Antibiofilm activity of bromelain from pineapple against Staphylococcus aureus

Bromelain is a set of proteolytic enzymes usually obtained from pineapple (Ananas comosus). Although bromelain has distinguished therapeutic properties, little is known about its proteolytic potential against opportunistic pathogens related to wound healing complications, such as Staphylococcus aureus. This study aimed toinvestigate the antibiofilm and antibacterial activity of bromelain in 43 clinical strains of S. aureusisolated from chronic wounds and blood cultures. Bromelain's activity against S. aureusbiofilm in vitrowas assessed by analyzing biofilm formation in cultures grownin the presence of 1% bromelain and biofilm destruction after the addition of 1% bromelain to mature biofilms. Proteinase K and sodium metaperiodate were also added to mature biofilms in parallel to compare their activity with that of bromelain and, together with exopolysaccharide and protein production rate assays, to determine the chemical composition of the biofilm extracellular matrix of selected strains of S. aureus. Bromelain was also evaluated for its DNase activity and impact on cellular hydrophobicity and auto-aggregation. Mueller-Hinton agar dilution was used to determine bromelain minimal inhibitory concentration (MIC). Biofilm assays showed that 1% bromelain significantly inhibits S. aureusbiofilm formation (p= 0.0157) by up to 4-fold and destroys its mature biofilms (p < 0.0001) by up to 6.4-fold, both compared to the control grown without bromelain. Biofilms of methicillin-resistant S. aureusstrains isolated from chronic wounds were the most affected by bromelain treatment. No antibacterial activity was detected with bromelain MIC assays and the proteolytic activity of bromelain was identified as the main antibiofilm mechanism of the enzyme, though its DNase activity may also contribute. The epithelial therapeutic properties of bromelain combined with its antibiofilm activity against S. aureusmake it a promising alternative to compose the therapeutic arsenal for the control of S. aureusbiofilms in the context of wound care.(AU)

Evaluation of methanolic crude extract of Linum usitatissimum for the removal of biofilm in diabetic foot isolates

Abstract Linum usitatissimum L is a widely used traditionally for multiple ailments. The present research was carried out to explore the antimicrobial, and anti-biofilm activity of crude extract of Linum usitatissimum L (Lu. Cr). Phytochemical and proximate analyses were performed. The bandages of diabetic foot patients were collected from the various hospitals. The bandages were cultured to isolate the bacterial strains present on it. The disc diffusion method was used to identify the antimicrobial potential whereas the minimum inhibitory concentration of the Lu.Cr were also determined. Proximate analysis confirms moisture content 8.33%, ash content 4.33%, crude protein 21.20%, crude fat 49.2% and crude fiber 5.63%. It was revealed that Gram-positive bacteria are most prevalent among all study groups. Lu.Cr possess significant bactericidal potential against S. aureus among all other microbes. Owing to this potential, linseed coated bandages can be used alternatively for the treatment of diabetic foot.

Resumo Linum usitatissimum L é amplamente utilizado tradicionalmente para doenças múltiplas. O presente trabalho foi realizado para explorar a atividade antimicrobiana e antibiofilme do extrato bruto de Linum usitatissimum L (Lu.Cr). Foram realizadas análises fitoquímicas e aproximadas. As ataduras de pacientes diabéticos com pé foram recolhidas nos vários hospitais. As bandagens foram cultivadas para isolar as cepas bacterianas presentes nas mesmas. O método de difusão em disco foi utilizado para identificar o potencial antimicrobiano e a concentração inibitória mínima do Lu.Cr também foi determinada. A análise aproximada confirma o teor de umidade 8,33%, teor de cinzas 4,33%, proteína bruta 21,20%, gordura bruta 49,2% e fibra bruta 5,63%. Foi revelado que as bactérias Gram-positivas são mais prevalentes entre todos os grupos de estudo. Lu.Cr possui potencial bactericida significativo contra S. aureus entre todos os outros micróbios. Devido a esse potencial, as ligaduras revestidas com linhaça podem ser utilizadas alternativamente para o tratamento do pé diabético.

Evaluation of methanolic crude extract of Linum usitatissimum for the removal of biofilm in diabetic foot isolates / Avaliação do extrato em bruto metanólico de Linum usitatissimum para remoção de biofilmes em isolados diabéticos de pé

Linum usitatissimum L is a widely used traditionally for multiple ailments. The present research was carried out to explore the antimicrobial, and anti-biofilm activity of crude extract of Linum usitatissimum L (Lu. Cr). Phytochemical and proximate analyses were performed. The bandages of diabetic foot patients were collected from the various hospitals. The bandages were cultured to isolate the bacterial strains present on it. The disc diffusion method was used to identify the antimicrobial potential whereas the minimum inhibitory concentration of the Lu.Cr were also determined. Proximate analysis confirms moisture content 8.33%, ash content 4.33%, crude protein 21.20%, crude fat 49.2% and crude fiber 5.63%. It was revealed that Gram-positive bacteria are most prevalent among all study groups. Lu.Cr possess significant bactericidal potential against S. aureus among all other microbes. Owing to this potential, linseed coated bandages can be used alternatively for the treatment of diabetic foot.

Linum usitatissimum L é amplamente utilizado tradicionalmente para doenças múltiplas. O presente trabalho foi realizado para explorar a atividade antimicrobiana e antibiofilme do extrato bruto de Linum usitatissimum L (Lu.Cr). Foram realizadas análises fitoquímicas e aproximadas. As ataduras de pacientes diabéticos com pé foram recolhidas nos vários hospitais. As bandagens foram cultivadas para isolar as cepas bacterianas presentes nas mesmas. O método de difusão em disco foi utilizado para identificar o potencial antimicrobiano e a concentração inibitória mínima do Lu.Cr também foi determinada. A análise aproximada confirma o teor de umidade 8,33%, teor de cinzas 4,33%, proteína bruta 21,20%, gordura bruta 49,2% e fibra bruta 5,63%. Foi revelado que as bactérias Gram-positivas são mais prevalentes entre todos os grupos de estudo. Lu.Cr possui potencial bactericida significativo contra S. aureus entre todos os outros micróbios. Devido a esse potencial, as ligaduras revestidas com linhaça podem ser utilizadas alternativamente para o tratamento do pé diabético.

Evaluation of methanolic crude extract of Linum usitatissimum for the removal of biofilm in diabetic foot isolates / Avaliação do extrato em bruto metanólico de Linum usitatissimum para remoção de biofilmes em isolados diabéticos de pé

Linum usitatissimum L is a widely used traditionally for multiple ailments. The present research was carried out to explore the antimicrobial, and anti-biofilm activity of crude extract of Linum usitatissimum L (Lu. Cr). Phytochemical and proximate analyses were performed. The bandages of diabetic foot patients were collected from the various hospitals. The bandages were cultured to isolate the bacterial strains present on it. The disc diffusion method was used to identify the antimicrobial potential whereas the minimum inhibitory concentration of the Lu.Cr were also determined. Proximate analysis confirms moisture content 8.33%, ash content 4.33%, crude protein 21.20%, crude fat 49.2% and crude fiber 5.63%. It was revealed that Gram-positive bacteria are most prevalent among all study groups. Lu.Cr possess significant bactericidal potential against S. aureus among all other microbes. Owing to this potential, linseed coated bandages can be used alternatively for the treatment of diabetic foot.(AU)

Linum usitatissimum L é amplamente utilizado tradicionalmente para doenças múltiplas. O presente trabalho foi realizado para explorar a atividade antimicrobiana e antibiofilme do extrato bruto de Linum usitatissimum L (Lu.Cr). Foram realizadas análises fitoquímicas e aproximadas. As ataduras de pacientes diabéticos com pé foram recolhidas nos vários hospitais. As bandagens foram cultivadas para isolar as cepas bacterianas presentes nas mesmas. O método de difusão em disco foi utilizado para identificar o potencial antimicrobiano e a concentração inibitória mínima do Lu.Cr também foi determinada. A análise aproximada confirma o teor de umidade 8,33%, teor de cinzas 4,33%, proteína bruta 21,20%, gordura bruta 49,2% e fibra bruta 5,63%. Foi revelado que as bactérias Gram-positivas são mais prevalentes entre todos os grupos de estudo. Lu.Cr possui potencial bactericida significativo contra S. aureus entre todos os outros micróbios. Devido a esse potencial, as ligaduras revestidas com linhaça podem ser utilizadas alternativamente para o tratamento do pé diabético.(AU)

Activity of rosemary (Rosmarinus officinalis - Family: Lamiaceae) essential oil compared to peracetic acid in Listeria monocytogenes biofilms

The objective of this study was to evaluate the activity of Rosmarinus officinalis essential oil (EO) compared to peracetic acid (PA) regarding formation and elimination of Listeria monocytogenes biofilms on polystyrene surface. The minimum inhibitory concentration (MIC) was determined according to standard protocol. Isolates were inoculated according to MIC standards polystyrene plate wells, which were then incubated at 37°C/96 hours for evaluation of biofilm formation. Regarding the evaluation of biofilm elimination, the biofilms were treated under MIC for 10 minutes. The MIC obtained were 2.0 and 3.0 mg mL-1 for EO and 0,015% for PA. Therefore, the results showed a reduction in the formation of biofilm with the presence of EO and PA, EO being more efficient (p < 0.05). Both compounds had a good capacity of eliminating biofilms, however the EO reduced the biofilm formation when compared to PA, highlighting its potential as an antibacterial agent and antibiofilm.(AU)

Chronic superficial infection in a dog caused by multidrug-resistant Pseudomonas aeruginosa

Background: Pseudomonas aeruginosa is a gram-negative aerobic bacterium and non-glucose fermenting, that usually causes opportunistic infections in animals, including humans. It is rarely involved in primary disease. The antibioticresistant bacterial strains are mainly developed due to the inappropriate use of antibiotics, however treating P. aeruginosa infections can be difficult owing to their natural resistance to antibiotics. Furthermorer resistant microorganisms such as P. aeruginosa grow by developing biofilms. Inaccurate diagnoses and absence of adequate microbiological tests can cause difficulties in resolving cases. This report describes a case of chronic superficial infection in a bitch caused by multidrugresistant Pseudomonas aeruginosa (MDR-PA). Case: A 6-year-old bitch Shih Tzu, initially presented with an exudative erythematous lesion in the snout region, which progressed to deep lesions, and spread to the back and limbs; furthermore, the animal always experienced a fever before new wounds emerged. Lesion samples, collected using a swab and processed at the Veterinary Microbiology Laboratory of the Federal University of Jatai (UFJ), revealed the presence of Pseudomonas aeruginosa. The isolate was multidrug-resistant and a carrier of TEM and ppyR genes. In the diffusion disk antibiogram, the isolate was found resistant to 14 different antibiotics belonging to 6 classes. Antimicrobial resistance was also tested using the minimum inhibitory concentration (MIC) test against imipenem, ceftazidime, ciprofloxacin, ticarcillin + clavulanic acid and aztreonam present in the MIC test strip. Treatment with amikacin and muporicin proved to be effective; however, owing to lesions extending to the face and palpebral involvement, the animal lost its eyeballs. Discussion: Pseudomonas aeruginosa is frequently associated with nosocomial infections mainly affecting immunosuppressed patients. Among the antibiotics tested, the group with the highest number of ineffective antibiotics was beta-lactams, where sensitivity was only observed for ticarcillin and ceftazidime. Recent studies have demonstrated that ceftazidime can reduce biofilm volume, inhibit motility, and repress the expression of genes associated with bacterial adhesion in P. aeruginosa. Therefore, the production of biofilm in P. aeruginosa is an important virulence factor as it facilitates a stable environment for the microorganism, which protects the bacteria from contact with antimicrobials. In addition, prolonged exposure to a wide variety of antimicrobials creates an environment of selective pressure between microorganisms, facilitating the emergence of multidrug-resistant strains. Furthermore, it is now well recognized that low doses of antibiotics, administered during continuous and fluctuating treatments, can stimulate biofilm establishment and are partly responsible for biofilm-specific antimicrobial tolerance. The resistance profile of P. aeruginosa isolated from dogs varies considerably, and the presence of isolates with a possible biofilm production capacity represents a challenge for the interpretation of the antimicrobial susceptibility profile. Culture and antibiogram is fundamentally important, both clinically and in environmental monitoring, in addition to the use of antibiogram data for decision making in clinical treatment.

Coriandrum sativum L. essential oil obtained from organic culture shows antifungal activity against planktonic and multibiofilm Candida / Óleo essencial de Coriandrum sativum L. obtido de cultura orgânica apresenta atividade antifúngica contra Candida planctônica e multibiofilme

This study aimed to analyze the phytochemical profile of essential oil obtained from the leaves of Coriandrum sativum L., and its antifungal activity against Candida spp. The research consisted of an in vitro study including collecting the vegetable product, analysis of its macronutrients, extraction, and chemical analysis of the essential oil, and assaying antifungal activity through minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), with growth inhibition kinetics, and the product's effects on multi-species Candida biofilm. Nitrogen (47.08 g Kg-1), phosphorus (5.3 g Kg-1) and potassium (50.46 g Kg-1) levels were within the normal range. The major constituents were octanal, decanal, dec-(2E)-enal, and dodecanal. The MIC and MFC of the product evaluated against 11 tested Candida strains ranged from 31.25 to 250 µg/mL. There was inhibition of fungal growth during 24 hours of exposure at the 3 concentrations tested (250, 125, and 62.5 µg/mL). The concentration of 80 mg/mL promoted the greatest reduction in multispecies biofilm (70% reduction in biofilm). Coriandrum sativum L. essential oil extract is principally constituted of alcohols and aldehydes and presents fungicidal activity against Candida spp. in its in planktonic and biofilm forms.

Este trabalho teve como objetivo analisar o perfil fitoquímico do óleo essencial obtido das folhas de Coriandrum sativum L., e sua atividade antifúngica contra Candida spp. A pesquisa consistiu em um estudo in vitro incluindo a coleta do produto vegetal, análise de seus macronutrientes, extração e análise química do óleo essencial e ensaio da atividade antifúngica por meio da concentração inibitória mínima (CIM) e concentração fungicida mínima (MFC), com crescimento cinética de inibição e os efeitos do produto no biofilme de Candida multi-espécies. Os níveis de nitrogênio (47,08 g Kg-1), fósforo (5,3 g Kg-1) e potássio (50,46 g Kg-1) estavam dentro da normalidade. Os principais constituintes foram octanal, decanal, dec-(2E)-enal e dodecanal. A CIM e CFM do produto avaliado contra 11 cepas de Candida testadas variaram de 31,25 a 250 µg/mL. Houve inibição do crescimento fúngico durante 24 horas de exposição nas 3 concentrações testadas (250, 125 e 62,5 µg/mL). A concentração de 80 mg/mL promoveu a maior redução no biofilme multiespécies (redução de 70% no biofilme). O extrato do óleo essencial de Coriandrum sativum L. é constituído principalmente por álcoois e aldeídos e apresenta atividade fungicida contra Candida spp. em suas formas planctônicas e biofilme.

Evaluation of methanolic crude extract of Linum usitatissimum for the removal of biofilm in diabetic foot isolates / Avaliação do extrato em bruto metanólico de Linum usitatissimum para remoção de biofilmes em isolados diabéticos de pé

Abstract Linum usitatissimum L is a widely used traditionally for multiple ailments. The present research was carried out to explore the antimicrobial, and anti-biofilm activity of crude extract of Linum usitatissimum L (Lu. Cr). Phytochemical and proximate analyses were performed. The bandages of diabetic foot patients were collected from the various hospitals. The bandages were cultured to isolate the bacterial strains present on it. The disc diffusion method was used to identify the antimicrobial potential whereas the minimum inhibitory concentration of the Lu.Cr were also determined. Proximate analysis confirms moisture content 8.33%, ash content 4.33%, crude protein 21.20%, crude fat 49.2% and crude fiber 5.63%. It was revealed that Gram-positive bacteria are most prevalent among all study groups. Lu.Cr possess significant bactericidal potential against S. aureus among all other microbes. Owing to this potential, linseed coated bandages can be used alternatively for the treatment of diabetic foot.

Resumo Linum usitatissimum L é amplamente utilizado tradicionalmente para doenças múltiplas. O presente trabalho foi realizado para explorar a atividade antimicrobiana e antibiofilme do extrato bruto de Linum usitatissimum L (Lu.Cr). Foram realizadas análises fitoquímicas e aproximadas. As ataduras de pacientes diabéticos com pé foram recolhidas nos vários hospitais. As bandagens foram cultivadas para isolar as cepas bacterianas presentes nas mesmas. O método de difusão em disco foi utilizado para identificar o potencial antimicrobiano e a concentração inibitória mínima do Lu.Cr também foi determinada. A análise aproximada confirma o teor de umidade 8,33%, teor de cinzas 4,33%, proteína bruta 21,20%, gordura bruta 49,2% e fibra bruta 5,63%. Foi revelado que as bactérias Gram-positivas são mais prevalentes entre todos os grupos de estudo. Lu.Cr possui potencial bactericida significativo contra S. aureus entre todos os outros micróbios. Devido a esse potencial, as ligaduras revestidas com linhaça podem ser utilizadas alternativamente para o tratamento do pé diabético.

Enterotoxigenic methicillin resistant Staphylococcus aureus contamination in salted fish from Gwadar Balochistan

Abstract Staphylococcus aureus is an important foodborne pathogen associated to food intoxication and other multiple infections in human being. Its presence in salted food is a serious issue due to its salt tolerance potential. A study was conducted to analyze the presence of enterotoxins producing drug resistance S. aureus in salted sea fish from Gwadar. Freshly persevered samples (n=50) of salted fish were subjected to analyze the presence of S. aureus using 16S rRNA and Nuc genes primers. The isolates were then evaluated for drug resistance and enterotoxins producing potential using specific primers for MecA (methicillin resistance gene), (SEA) staphylococcal enterotoxin A and (SEB) staphylococcal enterotoxin B genes. Total 13/50 (26%) of the samples were found positive for the presence of S. aureus, preliminary confirmed with biochemical profiling and finally with the help of target genes presence. The isolates were found showing 100% resistant to methicillin, which were molecularly confirmed by the presence of MecA gene present in genome. The isolates 5/13 (38%) were positive for SEA and 3/13 (23%) for SEB genes, whereas 2/13 (15%) were confirmed having both SEA and SEB genes in its genome. It was also confirmed that all the isolates were capable to form biofilm over the glass surfaces. It was concluded that the study confirmed the presence of enterotoxigenic methicillin resistance Staphylococcus aurous (MRSA) in salted fish product, that poses gross food safety concern. Preventive and control measures are necessary to handle this serious food safety concern.

Resumo Staphylococcus aureus é um importante patógeno de origem alimentar associado à intoxicação alimentar e outras infecções múltiplas em seres humanos. Sua presença em alimentos salgados é um problema sério devido ao seu potencial de tolerância ao sal. Um estudo foi realizado para analisar a presença de enterotoxinas produtoras de resistência a drogas S. aureus em peixes salgados do mar de Gwadar. Amostras recém-perseveradas (n = 50) de peixes salgados foram submetidas à análise da presença de S. aureus usando os primers dos genes 16S rRNA e Nuc. Os isolados foram então avaliados quanto à resistência a drogas e potencial de produção de enterotoxinas usando primers específicos para os genes MecA (gene de resistência à meticilina), (SEA) enterotoxina A estafilocócica e (SEB) enterotoxina B estafilocócica genes. Um total de 13/50 (26%) das amostras foi considerado positivas para a presença de S. aureus, confirmadas preliminarmente com perfis bioquímicos e finalmente com a ajuda da presença de genes-alvo. Os isolados foram encontrados com 100% de resistência à meticilina, os quais foram confirmados molecularmente pela presença do gene MecA no genoma. Os isolados 5/13 (38%) foram positivos para SEA e 3/13 (23%) para genes SEB, enquanto 2/13 (15%) foram confirmados tendo os genes SEA e SEB em seu genoma. Também foi verificado que todos os isolados foram capazes de formar biofilme sobre as superfícies de vidro. Concluiu-se que o estudo confirmou a presença de Staphylococcus aurous resistente à meticilina enterotoxigênica (MRSA) em produtos de peixe salgado, o que representa uma grande preocupação para a segurança alimentar. Medidas preventivas e de controle são necessárias para lidar com essa grave preocupação com a segurança alimentar.

Essential oils isolated from popular medicinal plants and spices as alternative antimicrobial and antibiofilm compounds against the pig pathogen Actinobacilluspleuropneumoniae / Óleos essenciais isolados de plantas medicinais e temperos populares como compostos antimicrobianos e antibiofilme alternativos contra o patógeno de suínosActinobacillus pleuropneumoniae

ABSTRACT: Actinobacilluspleuropneumoniae is the causative agent of swine pleuropneumonia, a contagious respiratory disease associated with high morbidity and economic losses. While antibiotic therapy helps to control the spreading of the pathogen on the farm, resistance to several classes of antibiotics were reported, and treatment can be impaired by the bacterial ability to form biofilms. This increases the need for alternative therapy approaches, including the use of natural compounds with antimicrobial and/or antibiofilm activities. In this research we analyzed, by the broth microdilution method, the inhibitory and bactericidal activities of the essential oils obtained from eighteen Brazilian popular medicinal plants or spices against clinical isolates of Actinobacilluspleuropneumoniae. After that, sub-inhibitory concentrations of active oils were tested for their antibiofilm effects, analyzed by the crystal violet method. Among the eighteen oils tested, eight (extracted from cinnamon, coriander, peppermint, spearmint, thyme, marjoram, eucalyptus, and laurel) presented bacteriostatic and bactericidal activities against all isolates, and subinhibitory concentrations of five of them disrupted up to 80% preformed biofilms, and significantly inhibited biofilm formation. The chemical composition of such oils was assessed by gas chromatography/mass spectrometry (GC/MS) and is presented, indicating that their bactericidal and antibiofilm properties were mostly associated with the presence of monoterpenes and phenylpropanoids. To our knowledge, this is the first report of essential oils with potential to control environmental contamination and animal infection with A. pleuropneumoniae, representing an alternative to increasing levels of antibiotic resistance.

RESUMO: Actinobacillus pleuropneumoniae é o agente causador da pleuropneumonia suína, uma doença respiratória contagiosa associada à alta morbidade e perdas econômicas. Embora a antibioticoterapia ajude a controlar a disseminação do patógeno na fazenda, a resistência a várias classes de antibióticos tem sido relatada e o tratamento pode ser prejudicado pela capacidade bacteriana de formar biofilmes. Isso aumenta a necessidade de abordagens terapêuticas alternativas, que incluem o uso de compostos naturais com atividades antimicrobianas e/ou antibiofilme. Neste trabalho, analisamos, pelo método de microdiluição em caldo nutriente, os efeitos inibitórios e bactericidas dos óleos essenciais obtidos de dezoito plantas medicinais brasileiras populares e/ou temperos contra isolados clínicos de Actinobacillus pleuropneumoniae. Então, concentrações subinibitórias dos óleos ativos foram testados quanto a suas atividades antibiofilme, analisados pelo método do cristal violeta. Dentre os dezoito óleos testados, oito (extraídos da canela, coentro, hortelã-pimenta, hortelã, tomilho, manjerona, eucalipto e louro) apresentaram atividade bacteriostática e bactericida contra todos os isolados, e concentrações subinibitórias de cinco deles romperam biofilmes pré-formados em até 80%, além de inibirem fortemente a formação de biofilmes. A composição química desses óleos foi avaliada por cromatografia gasosa/espectrometria de massa (CG/MS) e é apresentada, indicando que suas propriedades bactericidas e antibiofilme estavam principalmente associadas à presença de monoterpenos e fenilpropanóides. Este é o primeiro relato de óleos essenciais com potencial para controlar a contaminação ambiental e infecção animal por A. pleuropneumoniae, representando uma alternativa contra o crescente aumento de resistência bacteriana aos antibióticos.

Resistance determinants of emerging pathogens isolated from an intensive care unit as a parameter of population health conditions of the Legal Amazon microregion / Determinantes de resistência a patógenos emergentes isolados de uma unidade de terapia intensiva como parâmetro das condições de saúde da população da microrregião da Amazônia Legal

Bacteria responsible for causing infections are common in hospital environments, water, soil, and food products. The infection risk is intensified by the absence of public sanitation, poor quality of life, and food scarcity. These external factors promote the dissemination of pathogens by direct contamination or biofilm formation. In this work, we identified bacterial isolates obtained from intensive care units in the southern region of Tocantins, Brazil. We compared matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) techniques and 16S ribosomal ribonucleic acid (rRNA) molecular analysis; we also performed phenotypic characterization. Fifty-six isolates characterized using morphotinctorial tests were classified as gram-positive (80.4%; n = 45) and gram-negative (19.6%; n = 11) and were resistant to several antibiotic classes; notably, we identified the blaOXA-23 resistance gene in the ILH10 isolate. Microbial identification using MALDI-TOF MS resulted in the identification of Sphingomonas paucimobilis and Bacillus circulans. 16S rRNA sequencing revealed four isolates belonging to the genera Bacillus and Acinetobacter. The similarity was superior to 99% for Acinetobacter schindleri in the Basic Local Alignment Search Tool (BLAST), grouped in the clade superior to 90%. Several strains isolated from intensive care units (ICU) were resistant to various antibiotic classes. These techniques allowed for the identification of several microorganisms of importance in public health, enabling improvements in human infection control and proving the quality of inputs, food, and water.

As bactérias responsáveis por causar infecções são comuns em ambientes hospitalares, água, solo e produtos alimentícios. O risco de infecção é intensificado pela ausência de saneamento público, má qualidade de vida e escassez de alimentos. Esses fatores externos promovem a disseminação de patógenos por contaminação direta ou formação de biofilme. Neste trabalho, identificamos isolados bacterianos obtidos de unidades de terapia intensiva na região sul do Tocantins, Brasil. Comparamos técnicas de espectrometria de massa de tempo de voo com ionização por dessorção a laser assistida por matriz (MALDI-TOF MS) e análise molecular de ácido ribonucleico ribossômico 16S (rRNA); também realizamos caracterização fenotípica. Cinquenta e seis isolados caracterizados por testes morfotintoriais foram classificados como gram-positivos (80,3%; n = 45) e gram-negativos (19,6%; n = 11) e foram resistentes a várias classes de antibióticos; notavelmente, identificamos o gene de resistência blaOXA-23 no isolado de ILH10. A identificação microbiana usando MALDI-TOF MS resultou na identificação de Sphingomonas paucimobilis e Bacillus circulans. O sequenciamento do 16S rRNA revelou quatro isolados pertencentes aos gêneros Bacillus e Acinetobacter. A similaridade foi superior a 99% para Acinetobacter schindleri no BLAST, agrupado no clado superior a 90%. Várias cepas isoladas de ICU foram resistentes a várias classes de antibióticos. Essas técnicas permitiram a identificação de diversos microrganismos de importância em saúde pública, possibilitando melhorias no controle de infecções humanas e comprovando a qualidade dos insumos, alimentos e água.

Commercial mastitis vaccines - effects on mastitis rates and somatic cell counts in Saanen goats

Background: Staphylococcus spp. are the most frequently isolated microorganisms in mastitis cases of small ruminants. The virulence factors of Staphylococcus spp. are critical in the treatment. Therefore, preventive medicine and mastitis control programs, especially herd vaccinations are of great importance in the prevention of mastitis. However, it is not always easy to obtain these vaccines under field conditions. This study, it was aimed to compare the effects of different commercial Staphylococcus spp. vaccines licensed for bovines and species-specific mastitis vaccines on mastitis rates and somatic cell count (SCC) on Saanen goats on field conditions. Materials, Methods & Results: The animal material consisted of 115 (230 udder halves) nulliparous Saanen goats. Goats were randomly grouped as bovine vaccine 1 (BV1 , n = 58), bovine vaccine 2 (BV2 , n = 58), small ruminant vaccine (SRV, n = 56), and control (n = 56). Vaccines were administered to goats in 2 doses according to the label regimen. First milk samples were collected between 0-5 days in milk (DIM) for microbiological analysis and 25-35 DIM for SCC. The other milk samples were collected at 25-35 (1st month) DIM, 60-65 (2nd month) DIM, 85-95 (3rd month) DIM, 115-125 (4th month) DIM, 145-155 (5th month) DIM for microbiological analysis and SCC. Non-aureus staphylococci (NAS) and Staphylococcus aureus were the most frequently isolated microorganism. It was found that the total mastitis rate decreased in vaccine groups compared to the control group. A significant difference was found only in the BV2 and SRV groups. The significant difference in S. aureus infection was found only in the SRV group. Mastitis vaccines used in this study decreased the NAS mastitis rate, but no significant difference was observed. It was found that the clinical mastitis incidence decreased in all vaccine groups compared to the control group, and a significant difference was found between the BV2 and SRV groups compared to the control group (P < 0.05). Somatic cell count was lower in the SRV and BV2 groups compared to the control group (P < 0.05). Discussion: In this study, compatible with the previous reports NAS and S. aureus were the most frequently isolated microorganism. The diversity of virulence factors of Staphylococcus spp. also plays an important role in its high incidence. In some countries, mastitis vaccines used in cows are also administered to small ruminants for reducing infection rates. Similarly, in this study, it was found that the mastitis rate decreased in all vaccine groups compared to the control group. A significant difference was found only in the BV2 and SRV groups. It is thought that the reason for the statistical difference may be due to the biofilm antigen in the BV2 and SRV. In addition, J5 strain in the BV2 is estimated to be effective in reducing the prevalence of gram-negative mastitis. It was observed that the infection rates decreased in the vaccine groups, especially due to S. aureus and NAS. Spontaneous treatment rates were very close to each other between the groups. The reason for the high rate of spontaneous treatment in this study can be explained by the fact that the animals were young and in their 1st lactation. SCC was lower in all vaccine groups compared to the control group. This situation is associated with the decrease in infection rates related to the use of vaccines. It was observed that SCC was lower in the vaccine groups. In addition, SCC was found to be lower in this study compared to similar studies. However, it is evident that the use of species-specific vaccines in the SRV group significantly reduced the rates of total S. aureus mastitis, subclinical NAS mastitis, and new infections by NAS compared to other vaccines. Furthermore, the species-specific vaccine significantly increased the rate of spontaneous treatment for S. aureus mastitis.

Enterotoxigenic methicillin resistant Staphylococcus aureus contamination in salted fish from Gwadar Balochistan / Contaminação de Staphylococcus aureus resistente à meticilina enterotoxigênica em peixes salgados de Gwadar Balochistan

Staphylococcus aureus is an important foodborne pathogen associated to food intoxication and other multiple infections in human being. Its presence in salted food is a serious issue due to its salt tolerance potential. A study was conducted to analyze the presence of enterotoxins producing drug resistance S. aureus in salted sea fish from Gwadar. Freshly persevered samples (n=50) of salted fish were subjected to analyze the presence of S. aureus using 16S rRNA and Nuc genes primers. The isolates were then evaluated for drug resistance and enterotoxins producing potential using specific primers for MecA (methicillin resistance gene), (SEA) staphylococcal enterotoxin A and (SEB) staphylococcal enterotoxin B genes. Total 13/50 (26%) of the samples were found positive for the presence of S. aureus, preliminary confirmed with biochemical profiling and finally with the help of target genes presence. The isolates were found showing 100% resistant to methicillin, which were molecularly confirmed by the presence of MecA gene present in genome. The isolates 5/13 (38%) were positive for SEA and 3/13 (23%) for SEB genes, whereas 2/13 (15%) were confirmed having both SEA and SEB genes in its genome. It was also confirmed that all the isolates were capable to form biofilm over the glass surfaces. It was concluded that the study confirmed the presence of enterotoxigenic methicillin resistance Staphylococcus aurous (MRSA) in salted fish product, that poses gross food safety concern. Preventive and control measures are necessary to handle this serious food safety concern.

Staphylococcus aureus é um importante patógeno de origem alimentar associado à intoxicação alimentar e outras infecções múltiplas em seres humanos. Sua presença em alimentos salgados é um problema sério devido ao seu potencial de tolerância ao sal. Um estudo foi realizado para analisar a presença de enterotoxinas produtoras de resistência a drogas S. aureus em peixes salgados do mar de Gwadar. Amostras recém-perseveradas (n = 50) de peixes salgados foram submetidas à análise da presença de S. aureus usando os primers dos genes 16S rRNA e Nuc. Os isolados foram então avaliados quanto à resistência a drogas e potencial de produção de enterotoxinas usando primers específicos para os genes MecA (gene de resistência à meticilina), (SEA) enterotoxina A estafilocócica e (SEB) enterotoxina B estafilocócica genes. Um total de 13/50 (26%) das amostras foi considerado positivas para a presença de S. aureus, confirmadas preliminarmente com perfis bioquímicos e finalmente com a ajuda da presença de genes-alvo. Os isolados foram encontrados com 100% de resistência à meticilina, os quais foram confirmados molecularmente pela presença do gene MecA no genoma. Os isolados 5/13 (38%) foram positivos para SEA e 3/13 (23%) para genes SEB, enquanto 2/13 (15%) foram confirmados tendo os genes SEA e SEB em seu genoma. Também foi verificado que todos os isolados foram capazes de formar biofilme sobre as superfícies de vidro. Concluiu-se que o estudo confirmou a presença de Staphylococcus aurous resistente à meticilina enterotoxigênica (MRSA) em produtos de peixe salgado, o que representa uma grande preocupação para a segurança alimentar. Medidas preventivas e de controle são necessárias para lidar com essa grave preocupação com a segurança alimentar.

Monitoring periodontal lesions and their effects during pregnancy: microbiological aspects of the oral cavity and amniotic fluid in pregnant ewes / Monitoramento de lesões periodontais e seus efeitos na gestação: aspectos microbiológicos da cavidade bucal e líquido amniótico de ovelhas gestantes

Periodontitis affects the teeth supporting tissues, leading to tooth loss and damage to animal health. Evidence in humans suggests that oral microorganisms spread systemically, increasing the risk of pregnancy disorders such as miscarriage, prematurity, and low birth weight. This study aimed to verify whether periodontopathogenic microorganisms reach the transplacental unit, culminating in problems in pregnant ewes. After analyzing the oral cavity, 10 clinically healthy pregnant ewes (OGCH group) and 10 pregnant ewes with periodontitis (OGP group) were selected. The subgingival biofilm was collected for the polymerase chain reaction (PCR) test and amniotic fluid for both the PCR and interleukin (IL) analysis. Peripheral blood was collected for complete blood count, and analyses of IL-6, IL1-ß, and tumor necrosis factor-α were performed. Placental fragments were collected to assess the inflammatory changes using optical microscopy. After giving birth, both the ewes and their lambs were weighed. On clinical examination, a positive correlation between bleeding and suppuration (correlation index - CI=0.54), suppuration and marginal gingivitis (CI=0.34), and marginal gingivitis and edema (CI=0.54) was observed. The weights of the ewes (p=0.013) and their respective lambs (p=0.04) in the OGP group were lower than those of their OGCH group counterparts. The hematological analysis revealed that the OGP group ewes showed a slight increase in the mean corpuscular volume (p=0.2447), segmented cells (p=0.3375), and eosinophils (p=0.3823) when compared with the OGCH group ewes, without a statistical difference. Regarding the microorganisms detected in the oral cavity, there was a significant difference between the occurrence of periodontal pockets and the presence of Fusobacterium necrophorum (p=0.0328), Porphyromonas asaccharolytica (p=0.0392), and the Mollicutes class (p=0.0352). Staphylococcus genus (p=0.9107) and Archaea domain (p=0.7245) were detected in the amniotic samples of both groups, without a significant difference, whereas P. asaccharolytica (p=0.2685) was only detected in one sample in the OGCH group. The expression of cytokine IL-6 in the OGP group differed significantly between the prepartum and postpartum periods (p=0.0039); moreover, it differed significantly in the postpartum period between the OGCH and OGP groups (p=0.0198). Histological examination showed a higher percentage of placental changes in the OGP group (70%) than in the OGCH group, such as the presence of macrophages, neutrophils, plasma cells, and multifocal areas of calcification. These results do not corroborate the hypothesis of dissemination of oral microorganisms to the placental unit, suggesting that it constitutes placental isolation in sheep.

A periodontite afeta os tecidos de suporte dos dentes levando à perda dentária e danos à saúde do animal. Evidências em humanos sugerem que os microrganismos orais se espalham sistemicamente, aumentando o risco de distúrbios da gravidez, como aborto espontâneo, prematuridade e baixo peso ao nascer. Este estudo teve como objetivo verificar se microrganismos periodontopatogênicos atingem a unidade transplacentária, culminando em problemas em ovelhas gestantes. Após análise da cavidade oral, foram selecionadas 10 ovelhas gestantes clinicamente saudáveis (grupo OGCH) e 10 ovelhas gestantes com periodontite (grupo OGP). O biofilme subgengival foi coletado para o teste de reação em cadeia da polimerase (PCR) e o líquido amniótico para teste de PCR e análise de interleucina (IL). Sangue periférico foi coletado para hemograma completo e análises de IL-6, IL1-ß e fator de necrose tumoral-α foram realizadas. Fragmentos de placenta foram coletados para avaliação das alterações inflamatórias por meio de microscopia óptica. Após o parto, as ovelhas e seus cordeiros foram pesados. Ao exame clínico, observou-se correlação positiva entre sangramento e supuração (índice de correlação - IC=0,54), supuração e gengivite marginal (IC=0,34) e gengivite marginal e edema (IC=0,54). Os pesos das ovelhas (p=0,013) e de seus respectivos cordeiros (p=0,04) do grupo OGP foram inferiores aos do grupo OGCH. A análise hematológica revelou que as ovelhas do grupo OGP apresentaram discreto aumento no volume corpuscular médio (p=0,2447), células segmentadas (p=0,3375) e eosinófilos (p=0,3823) quando comparadas com as ovelhas do grupo OGCH, sem diferença estatística diferença. Em relação aos microrganismos detectados na cavidade oral, houve diferença significativa entre a ocorrência de bolsas periodontais e a presença de Fusobacterium necrophorum (p=0,0328), Porphyromonas asaccharolytica (p=0,0392) e da classe Mollicutes (p=0,0352). O gênero Staphylococcus (p=0,9107) e o domínio Archaea (p=0,7245) foram detectados nas amostras amnióticas de ambos os grupos, sem diferença significativa, enquanto P. asaccharolytica (p=0,2685) foi detectado apenas em uma amostra do grupo OGCH. A expressão da citocina IL-6 no grupo OGP diferiu significativamente entre os períodos pré e pós-parto (p=0,0039); além disso, diferiu significativamente no período pós-parto entre os grupos OGCH e OGP (p=0,0198). O exame histológico mostrou maior porcentagem de alterações placentárias no grupo OGP (70%) do que no grupo OGCH, como a presença de macrófagos, neutrófilos, plasmócitos e áreas multifocais de calcificação. Esses resultados não corroboram a hipótese de disseminação de microrganismos orais para a unidade placentária, sugerindo que se trata de um isolamento placentário em ovinos.

Enterotoxigenic methicillin resistant Staphylococcus aureus contamination in salted fish from Gwadar Balochistan / Contaminação de Staphylococcus aureus resistente à meticilina enterotoxigênica em peixes salgados de Gwadar Balochistan

Staphylococcus aureus is an important foodborne pathogen associated to food intoxication and other multiple infections in human being. Its presence in salted food is a serious issue due to its salt tolerance potential. A study was conducted to analyze the presence of enterotoxins producing drug resistance S. aureus in salted sea fish from Gwadar. Freshly persevered samples (n=50) of salted fish were subjected to analyze the presence of S. aureus using 16S rRNA and Nuc genes primers. The isolates were then evaluated for drug resistance and enterotoxins producing potential using specific primers for MecA (methicillin resistance gene), (SEA) staphylococcal enterotoxin A and (SEB) staphylococcal enterotoxin B genes. Total 13/50 (26%) of the samples were found positive for the presence of S. aureus, preliminary confirmed with biochemical profiling and finally with the help of target genes presence. The isolates were found showing 100% resistant to methicillin, which were molecularly confirmed by the presence of MecA gene present in genome. The isolates 5/13 (38%) were positive for SEA and 3/13 (23%) for SEB genes, whereas 2/13 (15%) were confirmed having both SEA and SEB genes in its genome. It was also confirmed that all the isolates were capable to form biofilm over the glass surfaces. It was concluded that the study confirmed the presence of enterotoxigenic methicillin resistance Staphylococcus aurous (MRSA) in salted fish product, that poses gross food safety concern. Preventive and control measures are necessary to handle this serious food safety concern.(AU)

Staphylococcus aureus é um importante patógeno de origem alimentar associado à intoxicação alimentar e outras infecções múltiplas em seres humanos. Sua presença em alimentos salgados é um problema sério devido ao seu potencial de tolerância ao sal. Um estudo foi realizado para analisar a presença de enterotoxinas produtoras de resistência a drogas S. aureus em peixes salgados do mar de Gwadar. Amostras recém-perseveradas (n = 50) de peixes salgados foram submetidas à análise da presença de S. aureus usando os primers dos genes 16S rRNA e Nuc. Os isolados foram então avaliados quanto à resistência a drogas e potencial de produção de enterotoxinas usando primers específicos para os genes MecA (gene de resistência à meticilina), (SEA) enterotoxina A estafilocócica e (SEB) enterotoxina B estafilocócica genes. Um total de 13/50 (26%) das amostras foi considerado positivas para a presença de S. aureus, confirmadas preliminarmente com perfis bioquímicos e finalmente com a ajuda da presença de genes-alvo. Os isolados foram encontrados com 100% de resistência à meticilina, os quais foram confirmados molecularmente pela presença do gene MecA no genoma. Os isolados 5/13 (38%) foram positivos para SEA e 3/13 (23%) para genes SEB, enquanto 2/13 (15%) foram confirmados tendo os genes SEA e SEB em seu genoma. Também foi verificado que todos os isolados foram capazes de formar biofilme sobre as superfícies de vidro. Concluiu-se que o estudo confirmou a presença de Staphylococcus aurous resistente à meticilina enterotoxigênica (MRSA) em produtos de peixe salgado, o que representa uma grande preocupação para a segurança alimentar. Medidas preventivas e de controle são necessárias para lidar com essa grave preocupação com a segurança alimentar.(AU)

Essential oils isolated from popular medicinal plants and spices as alternative antimicrobial and antibiofilm compounds against the pig pathogen Actinobacilluspleuropneumoniae / Óleos essenciais isolados de plantas medicinais e temperos populares como compostos antimicrobianos e antibiofilme alternativos contra o patógeno de suínosActinobacillus pleuropneumoniae

Actinobacilluspleuropneumoniae is the causative agent of swine pleuropneumonia, a contagious respiratory disease associated with high morbidity and economic losses. While antibiotic therapy helps to control the spreading of the pathogen on the farm, resistance to several classes of antibiotics were reported, and treatment can be impaired by the bacterial ability to form biofilms. This increases the need for alternative therapy approaches, including the use of natural compounds with antimicrobial and/or antibiofilm activities. In this research we analyzed, by the broth microdilution method, the inhibitory and bactericidal activities of the essential oils obtained from eighteen Brazilian popular medicinal plants or spices against clinical isolates of Actinobacilluspleuropneumoniae. After that, sub-inhibitory concentrations of active oils were tested for their antibiofilm effects, analyzed by the crystal violet method. Among the eighteen oils tested, eight (extracted from cinnamon, coriander, peppermint, spearmint, thyme, marjoram, eucalyptus, and laurel) presented bacteriostatic and bactericidal activities against all isolates, and subinhibitory concentrations of five of them disrupted up to 80% preformed biofilms, and significantly inhibited biofilm formation. The chemical composition of such oils was assessed by gas chromatography/mass spectrometry (GC/MS) and is presented, indicating that their bactericidal and antibiofilm properties were mostly associated with the presence of monoterpenes and phenylpropanoids. To our knowledge, this is the first report of essential oils with potential to control environmental contamination and animal infection with A. pleuropneumoniae, representing an alternative to increasing levels of antibiotic resistance.

Actinobacillus pleuropneumoniae é o agente causador da pleuropneumonia suína, uma doença respiratória contagiosa associada à alta morbidade e perdas econômicas. Embora a antibioticoterapia ajude a controlar a disseminação do patógeno na fazenda, a resistência a várias classes de antibióticos tem sido relatada e o tratamento pode ser prejudicado pela capacidade bacteriana de formar biofilmes. Isso aumenta a necessidade de abordagens terapêuticas alternativas, que incluem o uso de compostos naturais com atividades antimicrobianas e/ou antibiofilme. Neste trabalho, analisamos, pelo método de microdiluição em caldo nutriente, os efeitos inibitórios e bactericidas dos óleos essenciais obtidos de dezoito plantas medicinais brasileiras populares e/ou temperos contra isolados clínicos de Actinobacillus pleuropneumoniae. Então, concentrações subinibitórias dos óleos ativos foram testados quanto a suas atividades antibiofilme, analisados pelo método do cristal violeta. Dentre os dezoito óleos testados, oito (extraídos da canela, coentro, hortelã-pimenta, hortelã, tomilho, manjerona, eucalipto e louro) apresentaram atividade bacteriostática e bactericida contra todos os isolados, e concentrações subinibitórias de cinco deles romperam biofilmes pré-formados em até 80%, além de inibirem fortemente a formação de biofilmes. A composição química desses óleos foi avaliada por cromatografia gasosa/espectrometria de massa (CG/MS) e é apresentada, indicando que suas propriedades bactericidas e antibiofilme estavam principalmente associadas à presença de monoterpenos e fenilpropanóides. Este é o primeiro relato de óleos essenciais com potencial para controlar a contaminação ambiental e infecção animal por A. pleuropneumoniae, representando uma alternativa contra o crescente aumento de resistência bacteriana aos antibióticos.

Antiadhesion and antibiofilm potential of Fagonia indica from Cholistan desert against clinical multidrug resistant bacteria

Abstract High resistance to antimicrobials is associated with biofilm formation responsible for infectious microbes to withstand severe conditions. Therefore, new alternatives are necessary as biofilm inhibitors to control infections. In this study, the antimicrobial and antibiofilm activities of Fagonia indica extracts were evaluated against MDR clinical isolates. The extract exhibited its antibiofilm effect by altering adherence and disintegration of bacterial cell wall. Fagonia indica has antibacterial effect as minimum inhibitory concentration (MIC) values ranging from 125 to 500 µg mL-1 and minimum bactericidal concentration (MBC) value was 500-3000 µg mL-1 against multidrug resistant (MDR) clinical isolates. The extract exhibited its antibiofilm effect by altering adherence and disintegration of bacterial cell wall. Fagonia indica had antibacterial effect as minimum inhibitory concentration (MIC) values ranging from 125 to 500 µg mL-1 and minimum bactericidal concentration (MBC) value was 500-3000 µg mL-1 against MDR isolates. The maximum inhibitory effects of Fagonia indica chloroform extract on biofilm formation was observed on Staphylococcus aureus (71.84%) followed by Klebsiella pneumoniae (70.83%) after 48 hrs showing that inhibition is also time dependent. Our results about bacterial cell protein leakage indicated that MDR isolates treated with chloroform extract of Fagonia indica showed maximum protein leakage of K. pneumoniae (59.14 µg mL-1) followed by S. aureus (56.7 µg mL-1). Cell attachment assays indicated that chloroform extract resulted in a 43.5-53.5% inhibition of cell adherence to a polystyrene surface. Our results revealed that extracts of Fagonia indica significantly inhibited biofilm formation among MDR clinical isolates, therefore, could be applied as antimicrobial agents and cost effective biofilm inhibitor against these MDR isolates.

Resumo A alta resistência aos antimicrobianos está associada à formação de biofilme responsável por micróbios infecciosos para suportar condições severas. Portanto, novas alternativas são necessárias como inibidores de biofilme para controlar infecções. Neste estudo, as atividades antimicrobiana e antibiofilme dos extratos de Fagonia indica foram avaliadas contra isolados clínicos MDR. O extrato exibiu seu efeito antibiofilme ao alterar a aderência e a desintegração da parede celular bacteriana. Fagonia indica tem efeito antibacteriano com valores de concentração inibitória mínima (CIM) variando de 125 a 500 µg mL-1, e valor de concentração bactericida mínima (MBC) de 500-3000 µg mL-1 contra isolados clínicos multirresistentes (MDR). O extrato exibiu seu efeito antibiofilme ao alterar a aderência e a desintegração da parede celular bacteriana. Fagonia indica teve efeito antibacteriano com valores de concentração inibitória mínima (CIM) variando de 125 a 500 µg mL-1, e concentração bactericida mínima (MBC) de 500-3000 µg mL-1 contra isolados MDR. Os efeitos inibitórios máximos do extrato de clorofórmio Fagonia indica na formação de biofilme foi observada em Staphylococcus aureus (71,84%), seguido por Klebsiella pneumoniae (70,83%) após 48 horas, mostrando que a inibição também é dependente do tempo. Nossos resultados sobre extravasamento de proteínas de células bacterianas indicaram que isolados MDR tratados com extrato clorofórmico de Fagonia indica apresentaram vazamento máximo de proteínas de K. pneumoniae (59,14 µg mL-1), seguido por S. aureus (56,7 µg mL-1). Ensaios de fixação de células indicaram que o extrato de clorofórmio resultou em uma inibição de 43,5-53,5% da aderência das células a uma superfície de poliestireno. Nossos resultados revelaram que extratos de Fagonia indica inibiram significativamente a formação de biofilme entre isolados clínicos MDR, portanto, poderiam ser aplicados como agentes antimicrobianos e inibidores de biofilme de baixo custo contra esses isolados MDR.

Biofilm model on mice skin wounds

Purpose: To evaluate a biofilm model of Pseudomonas aeruginosa in excisional cutaneous wound in mice. Methods: Preclinical, translational study conducted with 64 C57BL/6 mice randomly assigned to control and intervention groups. Evaluation was on days D0, D3, D5, D7 and D10 of wound making. The profile of biofilm formation and induction was evaluated using wound closure kinetics, quantitative culture, and evaluation of wounds using transmission electron microscopy (TEM). Clinical evaluation was performed by liver tissue culture, weight variation, and quantification of leukocytes in peripheral blood. Analyses were performed with GraphPad Prism software. Results: Bacterial load for induction of infection with P. aeruginosa and survival of animals was 104 UFC·mL-1. In D5 (p < 0.0001) and D7 (p < 0.01), animals in the intervention group showed a delay in the healing process and had their wounds covered by necrotic tissue until D10. Statistical differences were observed in wound cultures and weight at D5 and D7 (p < 0.01). Liver cultures and leukocyte quantification showed no statistical differences. No bacteria in planktonic or biofilm form were identified by TEM. Conclusions: The findings raise questions about the understanding of the ease of formation and high occurrence of biofilm in chronic wounds.

Influence of the food matrix on dual-species biofilm of Listeria monocytogenes and Pseudomonas fluorescens

In the food industry, the formation of biofilms results in serious microbial recontamination problem. This work aimed to study Listeria sp. obtained from sliced products and food handling surfaces, for the preparation of food of animal origin to be consumed cold. Listeria monocytogenes, Listeria innocua and Listeria seeligeri were detected. In the evaluation of antibiotic susceptibility, the isolates were sensitive to ampicillin and penicillin, which were the main antibiotics used in treatment. The isolates showed the ability to form biofilm in microplate, in stainless steel and polypropylene surfaces, with a variation of sessile cells between 4.29±0.23 and 7.03±0.01 log10 CFU cm-2 in TSBYE. This ability was also observed in food matrix composed of UHT whole milk in mono-species cultivation and in associated cultivation of L. monocytogenes with Pseudomonas fluorescens. The application of sanitizers peracetic acid and sodium hypochlorite revealed efficiency in the eradication of adhered cells and biofilms formed in stainless steel surfaces. Therefore, Listeria sp. showed to be persistent and able to form biofilm in mono-species cultivation or associated with P. fluorescens, under different conditions. Taking these aspects into account, the need for proper hygiene in the food production process is highlighted in order to avoid risks to the consumers health.(AU)

Bacillus Cereus in Eggshell: Enterotoxigenic Profiles and Biofilm Production

A study was carried out with the objective of determining the presence of Bacillus cereus in eggshells commercialized in Mexico, the enterotoxigenic profile of the isolated strains, and the production of biofilms in different materials as well as in the eggshell. 1000 chicken eggs from four commercial brands were collected from markets and supermarkets located in the city of Chilpancingo, Mexico. Bacillus cereus was isolated from the eggshell. The molecular identification was by amplification of the gyrB gene and the enterotoxigenic profiles by the amplification of the cytK, ces, nheABC, and hblABD genes, in addition to the amplification of the tasA and sipW genes associated with the production of biofilms. In different materials and in eggshells, the production of biofilms was evaluated. The microbiological and molecular analysis of B. cereus yielded a frequency of 5.5% (55/1000), this was higher in brand III (11.6%, p=0.0001) and white eggshell (7.6%, 38/500, p≤0.001) and by marketing source, it was similar between market (5.2% / 26/500) and supermarket (5.8%, 29/500). The most common was the toxigenic profile A (23/55). Biofilm production is high in PVC in relation to other materials (p<0.0001), and the frequency of the related genes tasA and sipW was 72.7% and 40% respectively; the highest production was related to the tasA gene; in eggshell, most of the strains (54/55) were able to produce biofilm. Strains of B. cereus with toxigenic potential circulate and persist in this product, which shows the need for sanitary regulation in the country.(AU)