Microbial profile of the oral cavity of patients under mechanical ventilation is not influenced by the edentamento: an observational study / Perfil microbiano da cavidade oral em pacientes sob ventilação mecânica não é influenciado pelo edentameto: um estudo observacional

Objective: Understand whether the collection site (toothless or toothless) influences the frequency of bacteria in the oral cavity. It was performed as an observational, prospective, and cross-sectional study. Methods: Clinical samples of the oral surfaces of the teeth and/or cheek mucosa were collected in the oral cavity of 37 patients who underwent elective cardiac surgery in the preoperative period from May to July 2019. The clinical samples collected were subjected to identification of colonies and antimicrobial sensitivity tests. Results: It was observed that regardless of whether the collection site is toothless or toothless, the microbial profile, socio-demographic variables, comorbidities, and risk factors do not statistically influence the choice of the collection site. Conclusions: there wasn't statistical difference between the strains found at the collection sites. Practical Implications: the result found is relevant for other researchers that will work with oral cavity collections since the chosen collection site will not influence the frequency of strains found.

Objetivo: Compreender se o local de coleta (com dentes ou desdentado) influencia na frequência de bactérias na cavidade oral. Foi realizado como um estudo observacional, prospectivo e transversal. Métodos: Amostras clínicas das superfícies orais dos dentes e/ou mucosa jugal foram coletadas na cavidade oral de 37 pacientes submetidos à cirurgia cardíaca eletiva no período pré-operatório de maio a julho de 2019. As amostras clínicas coletadas foram submetidas à identificação de colônias e testes antimicrobianos de sensibilidade. Resultados: Observou-se que independente do local de coleta ser dentado ou desdentado, o perfil microbiano, variáveis sociodemográficas, comorbidades e fatores de risco não influenciam estatisticamente na escolha do local de coleta. Conclusões: Não houve diferença estatística entre as cepas encontradas nos locais de coleta. O resultado encontrado é relevante para outros pesquisadores que trabalharão com coletas de cavidade oral, pois o local de coleta escolhido não influenciará na frequência de cepas encontradas.

A Randomized Comparison Study of Lyophilized Nile Tilapia Skin and Silver-Impregnated Sodium Carboxymethylcellulose for the Treatment of Superficial Partial-Thickness Burns.

Glycerolized Nile tilapia skin (NTS) showed promising results when used for burn treatment in phases II and III randomized controlled trials. This pilot study aims to evaluate the effectiveness of lyophilized NTS (LNTS) as a temporary skin substitute for superficial partial-thickness burns by comparing it with silver-impregnated sodium carboxymethylcellulose dressing. This was a randomized, prospective, open-label, and controlled pilot study conducted in Fortaleza, Brazil, from April 2019 to December 2019. The 24 participants had ≥18 and ≤70 years of age and superficial partial-thickness burns affecting up to 10% of TBSA. Primary outcomes were the number of dressings performed and pain intensity, assessed via the Visual Analogue Scale and the Electronic von Frey. Secondary outcomes were the level of pain-related anxiety, assessed via the Burns Specific Pain Anxiety Scale, and analgesic consumption. In the test group, the number of dressings and the patient-reported pain after dressing-related procedures were lower. Analgesic intake, pain-related anxiety, and both patient-reported and objectively measured pain before dressing-related procedures were similar for the treatment groups. No adverse effects were detected. LNTS shares the same characteristics of an "'ideal'" wound dressing demonstrated by glycerolized NTS in previous studies. Also, it demonstrated noninferiority for burn management when compared with silver-impregnated sodium carboxymethylcellulose dressing. The safety and efficacy of LNTS demonstrated in this pilot study may allow the development of larger phases II and III RCTs in a near future.

Influence of preoperative hospital stay in the antimicrobial resistance profile of oral microbiotic / Influência do tempo de permanência hospitalar pré-operatória no perfil de resistência a antimicrobianos da Microbiota oral

Objective: Verify whether there was a relationship between the occurrence of multidrug-resistant bacterial strains and the length of stay in the preoperative period. Methods: Clinical samples of the oral surfaces of the teeth and/or cheek mucosa were collected in the oral cavity of 37 patients who underwent elective cardiac surgery in the preoperative period from May to July 2019. The clinical samples collected were subjected to identification of colonies and antimicrobial sensitivity tests. Results: We observed that the patients who stayed for more than 60 days in that hospital had 17 times more likely to develop multi-resistant strains (Multi-Rs) than those that have not remained. Conclusions: We realized that the longer the patient stays in the hospital, the greater the chances of bacterial strains Multi-Rs. Therefore, it is important to try to reduce the length of hospital stay so that there is no increase in the occurrence of multiresistant strains in these patients

Objetivo: Verificar se houve relação entre a ocorrência de cepas bacterianas multirresistentes e o tempo de internação no pré-operatório. Métodos: Amostras clínicas das superfícies orais dos dentes e / ou mucosa jugal foram coletadas na cavidade oral de 37 pacientes submetidos à cirurgia cardíaca eletiva no período pré-operatório de maio a julho de 2019. As amostras clínicas coletadas foram submetidas à identificação de colônias e testes de sensibilidade antimicrobiana. Resultados: Observamos que os pacientes que permaneceram por mais de 60 dias naquele hospital tiveram 17 vezes mais chance de desenvolver cepas multirresistentes (Multi-Rs) do que os que não permaneceram. Conclusões: Percebemos que quanto mais tempo o paciente permanece internado, maiores são as chances de cepas bacterianas Multi-Rs. Portanto, é importante tentar reduzir o tempo de internação hospitalar para que não haja aumento na ocorrência de cepas multirresistentes nesses pacientes.

Antimicrobial effect of anacardic acid-loaded zein nanoparticles loaded on Streptococcus mutans biofilms.

Bacterial biofilms play a key role in the pathogenesis of major oral diseases. Nanoparticles open new paths for drug delivery in complex structures such as biofilms. This study evaluated the antimicrobial effect of zein nanoparticles containing anacardic acid (AA) extracted from cashew shells of Anacardium occidentale on in vitro Streptococcus mutans biofilm formation and mature biofilms. The minimum inhibitory concentration (MIC), minimum bacterial concentration (MBC), and antibiofilm assays were performed. Streptococcus mutans UA159 biofilms were formed on saliva-coated hydroxyapatite disk for 5 days. To evaluate the preventive effect on biofilm formation, before contact with the inoculum, the disks were immersed once for 2 min in (1) hydroethanolic solution; (2) blank zein nanoparticles; (3) zein nanoparticles containing AA; and (4) 0.12% chlorhexidine gluconate. To determine the effect against mature biofilms, the disks containing 5-day preformed biofilms were further treated using the same procedure. The bacterial viability and dry weight were determined for both assays and used to compare the groups using ANOVA followed by Tukey's test (p < 0.05). Both MIC and MBC for AA-loaded zein nanoparticles were 0.36 µg/mL. Groups 3 and 4 were very effective in inhibiting S. mutans biofilm formation, as no colony-forming units were detected. In contrast, for mature biofilms, no difference in bacterial viability (p = 0.28) or dry weight (p = 0.09) was found between the treatments. Therefore, the AA-based nanoformulation presented very high inhibitory and bactericidal activities against planktonic S. mutans, and the results indicate a strong antiplaque effect. However, the formulation showed no antimicrobial effect on the established biofilm.

Zika Virus Infection and Microcephaly: A Case-Control Study in Brazil.

BACKGROUND: Brazil presented an alarming number of newborns with microcephaly in the years 2015 and 2016. The investigation of the cases raised the suspicion of the association of these cases with maternal infections by the zika virus. Also, in 2015, there was an epidemic of zika virus infection in Brazil, reinforcing this hypothesis. OBJECTIVE: The objective of this study was to identify factors associated with the diagnosis of microcephaly in newborns, including zika virus infection. METHODS: We conducted a case-control study. The cases were defined as children who received clinical and imaging diagnosis of microcephaly, born after October 2015 in Ceará, Brazil, which recorded the highest number of microcephaly cases in Brazil during the outbreak. The cases were identified in medical records of public and private maternity hospitals and in child development stimulation clinics tracked until June 2017. Epidemiological, clinical, and socioeconomic variables were collected, visiting their homes and confirming data from their medical records. Controls were children without microcephaly identified in the vicinity of the residence of each case. Logistic regression models were used to control confounding. FINDINGS: We evaluated 58 cases and 116 controls. The odds of having a baby with microcephaly was 14 times higher among mothers who had zika virus infection (p < 0.001), after multivariate analysis. Arboviruses infections symptoms, as fever (p = 0.220), skin change (p < 0.001), and joint pain (p = 0.002) also demonstrated an association with microcephaly. CONCLUSIONS: Maternal infection zika virus was associated with a diagnosis of microcephaly. Our study contributes to the investigation of the epidemiological factors associated with the diagnosis of microcephaly.

Clinical and environmental isolates of Burkholderia pseudomallei from Brazil: Genotyping and detection of virulence gene.

OBJECTIVE: To evaluate the genetic diversity of clinical and environmental isolates of Burkholderia pseudomallei (B. pseudomallei) recovered in Ceará, Brazil, and screen these isolates for the presence of type three secretion system virulence gene. METHODS: Nineteen B. pseudomallei isolates (9 from clinical cases and 10 from soils) were analyzed. Random amplified polymorphic DNA was performed with primers OPQ-2, OPQ-4 and OPQ-16 to evaluate the genetic diversity, and type three secretion system gene was detected through polymerase chain reaction. RESULTS: Random amplified polymorphic DNA showed a genetic relatedness of approximately 50% among the tested B. pseudomallei isolates, which were grouped into two clades, of which the biggest ones comprised 18/19 isolates for primer OPQ-2, and 17/19 isolates for primer OPQ-16. Primer OPQ-4 grouped the isolates into three clades comprising 1/19, 3/19 and 15/19 isolates. Additionally, type three secretion system gene was detected in all tested isolates. CONCLUSIONS: This is an effort to type B. pseudomallei strains from Ceará, which is important for better understanding this pathogen, contributing for the epidemiological surveillance of melioidosis in this endemic region.

Promethazine improves antibiotic efficacy and disrupts biofilms of Burkholderia pseudomallei.

Efflux pumps are important defense mechanisms against antimicrobial drugs and maintenance of Burkholderia pseudomallei biofilms. This study evaluated the effect of the efflux pump inhibitor promethazine on the structure and antimicrobial susceptibility of B. pseudomallei biofilms. Susceptibility of planktonic cells and biofilms to promethazine alone and combined with antimicrobials was assessed by the broth microdilution test and biofilm metabolic activity was determined with resazurin. The effect of promethazine on 48 h-grown biofilms was also evaluated through confocal and electronic microscopy. The minimum inhibitory concentration (MIC) of promethazine was 780 mg l-1, while the minimum biofilm elimination concentration (MBEC) was 780-3,120 mg l-1. Promethazine reduced the MIC values for erythromycin, trimethoprim/sulfamethoxazole, gentamicin and ciprofloxacin and reduced the MBEC values for all tested drugs (p<0.05). Microscopic analyses demonstrated that promethazine altered the biofilm structure of B. pseudomallei, even at subinhibitory concentrations, possibly facilitating antibiotic penetration. Promethazine improves antibiotics efficacy against B. pseudomallei biofilms, by disrupting biofilm structure.

Aeromonas and Plesiomonas species from scarlet ibis (Eudocimus ruber) and their environment: monitoring antimicrobial susceptibility and virulence.

The present study aimed at evaluating the role of captive scarlet ibises (Eudocimus ruber) and their environment as reservoirs of Aeromonas spp. and Plesiomonas spp., and analyzing the in vitro antimicrobial susceptibility and virulence of the recovered bacterial isolates. Thus, non-lactose and weak-lactose fermenting, oxidase positive Gram-negative bacilli were recovered from cloacal samples (n = 30) of scarlet ibises kept in a conservational facility and from water samples (n = 30) from their environment. Then, the antimicrobial susceptibility, hemolytic activity and biofilm production of the recovered Aeromonas spp. and Plesiomonas shigelloides strains were assessed. In addition, the virulence-associated genes of Aeromonas spp. were detected. Ten Aeromonas veronii bv. sobria, 2 Aeromonas hydrophila complex and 10 P. shigelloides were recovered. Intermediate susceptibility to piperacillin-tazobactam and cefepime was observed in 2 Aeromonas spp. and 1 P. shigelloides, respectively, and resistance to gentamicin was observed in 4 P. shigelloides. The automated susceptibility analysis revealed resistance to piperacillin-tazobactam and meropenem among Aeromonas spp. and intermediate susceptibility to gentamicin among P. shigelloides. All Aeromonas isolates presented hemolytic activity, while 3 P. shigelloides were non-hemolytic. All Aeromonas spp. and 3/10 P. shigelloides were biofilm-producers, at 28 °C, while 10 Aeromonas spp. and 6/10 P. shigelloides produced biofilms, at 37 °C. The most prevalent virulence genes of Aeromonas spp. were asa1 and ascV. Scarlet ibises and their environment harbour potentially pathogenic bacteria, thus requiring monitoring and measures to prevent contamination of humans and other animals.

Terpinen-4-ol, tyrosol, and ß-lapachone as potential antifungals against dimorphic fungi

Abstract This study aimed to evaluate the in vitro antifungal activity of terpinen-4-ol, tyrosol, and β-lapachone against strains of Coccidioides posadasii in filamentous phase (n = 22) and Histoplasma capsulatum in both filamentous (n = 40) and yeast phases (n = 13), using the broth dilution methods as described by the Clinical and Laboratory Standards Institute, to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of these compounds. The mechanisms of action of these compounds were also investigated by analyzing their effect on cell membrane permeability and ergosterol synthesis. The MIC and MFCf these compounds against C. posadasii, mycelial H. capsulatum, and yeast-like H. capsulatum, were in the following ranges: 350-5720 µg/mL, 20-2860 µg/mL, and 40-1420 µg/mL, respectively for terpinen-4-ol; 250-4000 µg/mL, 30-2000 µg/mL, and 10-1000 µg/mL, respectively, for tyrosol; and 0.48-7.8 µg/mL, 0.25-16 µg/mL, and 0.125-4 µg/mL, respectively for β-lapachone. These compounds showed a decrease in MIC when the samples were subjected to osmotic stress, suggesting that the compounds acted on the fungal membrane. All the compounds were able to reduce the ergosterol content of the fungal strains. Finally, tyrosol was able to cause a leakage of intracellular molecules.

Characterization of the microbiota of the skin and oral cavity of Oreochromis niloticus / Caracterização da microbiota da pele e cavidade oral de Oreochromis niloticus

Introduction: Fish are usually exposed to higher microbial loads than land or air animals. The microbiota of fish mostly consists of Pseudomonas spp., Aeromonas spp., Shewanella putrefasciens, Acinetobacter spp. and Moraxella spp. Objective: to analyze the oral cavity, and skin tissue microbiota on the Nile tilapia (Oreochromis niloticus), a fish species raised commercially in Brazil. Methods: Samples were collected from the oral cavity and skin of 20 Nile tilapia specimens (Oreochromis niloticus), each weighing approximately 1,000 grams. The samples were cultures for quantitative analysis on sheep blood agar (SBA) and chromID™ CPS® agar (CPS). Results: Eleven different bacterial species were identified on CPS and SBA plates. Gram-negative species were the most prevalent, while gram-positive Globicatella spp, Streptococcus spp and Enterococcus faecalis were also found. Pseudomonas aeruginosa species were isolated from all samples. Gram-positive Enterococcus faecalis was found in 70 and 60% of the skin and oral samples, respectively. Conclusion: For all samples studied, the microbial load was less than 100,000 colony-forming units - CFU/g of tissue. This value is a cutoff standardized for the American Society of Microbiology to differentiate the causal agent from the colonizers. In light of this result and considering the absence of infectious signs in the fish samples, we conclude that the CFU values found in this study reflect a normal, non-infectious colonization/microbiota. (AU)

Introdução: Os peixes são normalmente expostos a cargas microbianas mais elevadas do que os animais em terra ou ar. O perfil da microbiota em peixes compreende principalmente Pseudomonas spp., Aeromonas spp., Shewanella putrefasciens, Acinetobacter spp., e Moraxella spp. Objetivo: analisar a microbiota da cavidade oral e do tecido da pele no Tilápia do Nilo (Oreochromis niloticus), comercialmente criado no Brasil. Métodos: Vinte espécimes de Tilápia do Nilo (Oreochromis niloticus), cada uma pesando cerca de 1.000 gramas, foram submetidas a coleta de amostras da cavidade oral e da pele. Estas amostras foram cultivadas quantitativamente em ágar sangue de carneiro (SBA) e chromID® CPS® agar (CPS). Resultados: Foram identificadas 11 diferentes espécies de bactérias em placas CPS e SBA. Os resultados mostram que bacilos gram-negativos são os mais prevalentes. Cocos gram-positivos como Globicatella spp, Streptococcus spp e Enterococcus faecalis também foram encontrados. Espécies de Pseudomonas aeruginosa foram isoladas a partir de todas as amostras. Enterococcus faecalis foi encontrado em 70 e 60% das amostras de pele e por via oral, respectivamente. Conclusão: Os resultados deste estudo mostram, para todas as amostras estudadas, uma carga de CFU de menos de 100.000 unidades formadoras de colonias - UFC / g de tecido. Este valor é um cutoff padronizado pela Sociedade Americana de Microbiologia, a fim de diferenciar o agente causal dos colonizadores. Diante destes resultados e considerando a ausência de sinais infecciosos nas amostras de peixes, conclui-se que os valores CFU's encontrados neste estudo consistem em colonização/ microbiota. (AU)

Terpinen-4-ol, tyrosol, and ß-lapachone as potential antifungals against dimorphic fungi.

This study aimed to evaluate the in vitro antifungal activity of terpinen-4-ol, tyrosol, and ß-lapachone against strains of Coccidioides posadasii in filamentous phase (n=22) and Histoplasma capsulatum in both filamentous (n=40) and yeast phases (n=13), using the broth dilution methods as described by the Clinical and Laboratory Standards Institute, to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of these compounds. The mechanisms of action of these compounds were also investigated by analyzing their effect on cell membrane permeability and ergosterol synthesis. The MIC and MFCf these compounds against C. posadasii, mycelial H. capsulatum, and yeast-like H. capsulatum, were in the following ranges: 350-5720µg/mL, 20-2860µg/mL, and 40-1420µg/mL, respectively for terpinen-4-ol; 250-4000µg/mL, 30-2000µg/mL, and 10-1000µg/mL, respectively, for tyrosol; and 0.48-7.8µg/mL, 0.25-16µg/mL, and 0.125-4µg/mL, respectively for ß-lapachone. These compounds showed a decrease in MIC when the samples were subjected to osmotic stress, suggesting that the compounds acted on the fungal membrane. All the compounds were able to reduce the ergosterol content of the fungal strains. Finally, tyrosol was able to cause a leakage of intracellular molecules.

Synthesis and in vitro antifungal activity of isoniazid-derived hydrazones against Coccidioides posadasii.

Coccidioidomycosis is a potentially severe infection caused by dimorphic fungi Coccidioides immitis and Coccidioides posadasii. Although guidelines are well established, refractory disease is a matter of concern in the clinical management of coccidioidomycosis. In the present study three isoniazid-derived hydrazones N'-[(E)-1-(4-methoxyphenyl)ethylidene]pyridine-4-carbohydrazide, N'-[(E)-1-(4-methylphenyl)ethylidene]pyridine-4-carbohydrazide, and N'-[(E)-1-(phenyl)ethylidene]pyridine-4-carbohydrazide were synthesized and evaluated for antifungal activity against C. posadasii. Susceptibility assays were performed by macrodilution testing. Interactions between the hydrazones and amphotericin B or itraconazole were evaluated by the checkerboard method. We also investigated the impairment of such compounds on cell ergosterol and membrane integrity. The synthesized molecules were able to inhibit C. posadasii in vitro with MIC values that ranged from 25 to 400 µg/mL. Drug interactions between synthesized molecules and amphotericin B proved synergistic for the majority of tested isolates; regarding itraconazole, synergism was observed only when strains were tested against N'-[(E)-1-(phenyl)ethylidene]pyridine-4-carbohydrazide. Reduction of cellular ergosterol was observed when strains were challenged with the hydrazones alone or combined with antifungals. Only N'-[(E)-1-(4-methylphenyl)ethylidene]pyridine-4-carbohydrazide altered membrane permeability of C. posadasii cells. Isoniazid-derived hydrazones were able to inhibit C. posadasii cells causing reduction of ergosterol content and alterations in the permeability of cell membrane. This study confirms the antifungal potential of hydrazones against pathogenic fungi.

Enterobacteria and Vibrio from Macrobrachium amazonicum prawn farming in Fortaleza, Ceará, Brazil.

OBJECTIVE: To investigate the isolation of enterobacteria associated with Macrobrachium amazonicum (M. amazonicum) farming and evaluate the in vitro antimicrobial susceptibility of Vibrio strains. METHODS: Strains were isolated from female M. amazonicum prawns and environmental and hatchery water. Biochemical assays were used to identify bacterial genera and those belonging to the genus Vibrio were submitted to further analyses for species identification, through Vitek 2 automated system and serotyping. Susceptibility test was performed according to Clinical Laboratory Standards Institute. RESULTS: The following genera of enterobacteria were recovered: Enterobacter (n = 11), Citrobacter (n = 10), Proteus (n = 2), Serratia (n = 2), Kluyvera (n = 2), Providencia (n = 2), Cedecea (n = 1), Escherichia (n = 1), Edwardsiella (n = 1) and Buttiauxella (n = 1). As for Vibrio, three species were identified: Vibrio cholerae non-O1/non-O139 (n = 4), Vibrio vulnificus (V. vulnificus) (n = 1) and Vibrio mimicus (n = 1). Vibrio spp. showed minimum inhibitory concentrations values within the susceptibility range established by Clinical Laboratory Standards Institute for almost all antibiotics, except for V. vulnificus, which presented intermediate profile to ampicillin. CONCLUSIONS: Enterobacteria do not seem to be the most important pathogens associated with M. amazonicum farming, whereas the recovery of Vibrio spp. from larviculture, with emphasis on Vibrio cholerae and V. vulnificus, deserves special attention due to their role as potentially zoonotic aquaculture-associated pathogens. Furthermore, the intermediate susceptibility of V. vulnificus to ampicillin reflects the importance of monitoring drug use in prawn farming.

Inhibition of heat-shock protein 90 enhances the susceptibility to antifungals and reduces the virulence of Cryptococcus neoformans/Cryptococcus gattii species complex.

Heat-shock proteins (Hsps) are chaperones required for the maintenance of cellular homeostasis in different fungal pathogens, playing an important role in the infectious process. This study investigated the effect of pharmacological inhibition of Hsp90 by radicicol on the Cryptococcus neoformans/Cryptococcus gattii species complex--agents of the most common life-threatening fungal infection amongst immunocompromised patients. The influence of Hsp90 inhibition was investigated regarding in vitro susceptibility to antifungal agents of planktonic and sessile cells, ergosterol concentration, cell membrane integrity, growth at 37 °C, production of virulence factors in vitro, and experimental infection in Caenorhabditis elegans. Hsp90 inhibition inhibited the in vitro growth of planktonic cells of Cryptococcus spp. at concentrations ranging from 0.5 to 2 µg ml(-1) and increased the in vitro inhibitory effect of azoles, especially fluconazole (FLC) (P < 0.05). Inhibition of Hsp90 also increased the antifungal activity of azoles against biofilm formation and mature biofilms of Cryptococcus spp., notably for Cryptococcus gattii. Furthermore, Hsp90 inhibition compromised the permeability of the cell membrane, and reduced planktonic growth at 37 °C and the capsular size of Cryptococcus spp. In addition, Hsp90 inhibition enhanced the antifungal activity of FLC during experimental infection using Caenorhabditis elegans. Therefore, our results indicate that Hsp90 inhibition can be an important strategy in the development of new antifungal drugs.

Simvastatin inhibits planktonic cells and biofilms ofCandida and Cryptococcusspecies

ABSTRACTThe antifungal activity of some statins against different fungal species has been reported. Thus, at the first moment, the in vitro antifungal activity of simvastatin, atorvastatin and pravastatin was tested againstCandida spp. and Cryptococcus spp. Then, in a second approach, considering that the best results were obtained for simvastatin, this drug was evaluated in combination with antifungal drugs against planktonic growth and tested against biofilms ofCandida spp. and Cryptococcus spp. Drug susceptibility testing was performed using the microdilution broth method, as described by the Clinical and Laboratory Standards Institute. The interaction between simvastatin and antifungals against planktonic cells was analyzed by calculating the fractional inhibitory concentration index. Regarding biofilm susceptibility, simvastatin was tested against growing biofilm and mature biofilm of one strain of each tested yeast species. Simvastatin showed inhibitory effect against Candida spp. andCryptococcus spp. with minimum inhibitory concentration values ranging from 15.6 to 1000 mg L-1 and from 62.5 to 1000 mg L-1, respectively. The combination of simvastatin with itraconazole and fluconazole showed synergism against Candidaspp. and Cryptococcus spp., while the combination of simvastatin with amphotericin B was synergistic only againstCryptococcus spp. Concerning the biofilm assays, simvastatin was able to inhibit both growing biofilm and mature biofilm ofCandida spp. and Cryptococcus spp. The present study showed that simvastatin inhibits planktonic cells and biofilms ofCandida and Cryptococcus species.

Inhibitory activity of isoniazid and ethionamide against Cryptococcus biofilms.

In recent years, the search for drugs to treat systemic and opportunistic mycoses has attracted great interest from the scientific community. This study evaluated the in vitro inhibitory effect of the antituberculosis drugs isoniazid and ethionamide alone and combined with itraconazole and fluconazole against biofilms of Cryptococcus neoformans and Cryptococcus gattii. Antimicrobials were tested at defined concentrations after susceptibility assays with Cryptococcus planktonic cells. In addition, we investigated the synergistic interaction of antituberculosis drugs and azole derivatives against Cryptococcus planktonic cells, as well as the influence of isoniazid and ethionamide on ergosterol content and cell membrane permeability. Isoniazid and ethionamide inhibited both biofilm formation and viability of mature biofilms. Combinations formed by antituberculosis drugs and azoles proved synergic against both planktonic and sessile cells, showing an ability to reduce Cryptococcus biofilms by approximately 50%. Furthermore, isoniazid and ethionamide reduced the content of ergosterol in Cryptococcus spp. planktonic cells and destabilized or permeabilized the fungal cell membrane, leading to leakage of macromolecules. Owing to the paucity of drugs able to inhibit Cryptococcus biofilms, we believe that the results presented here might be of interest in the designing of new antifungal compounds.

Evidence of Fluconazole-Resistant Candida Species in Tortoises and Sea Turtles.

The aim of this study was to evaluate the antifungal susceptibility of Candida spp. recovered from tortoises (Chelonoidis spp.) and sea turtles (Chelonia mydas, Caretta caretta, Lepidochelys olivacea, Eretmochelys imbricata). For this purpose, material from the oral cavity and cloaca of 77 animals (60 tortoises and 17 sea turtles) was collected. The collected specimens were seeded on 2% Sabouraud dextrose agar with chloramphenicol, and the identification was carried out by morphological and biochemical methods. Sixty-six isolates were recovered from tortoises, out of which 27 were C. tropicalis, 27 C. famata, 7 C. albicans, 4 C. guilliermondii and 1 C. intermedia, whereas 12 strains were obtained from sea turtles, which were identified as Candida parapsilosis (n = 4), Candida guilliermondii (n = 4), Candida tropicalis (n = 2), Candida albicans (n = 1) and Candida intermedia (n = 1). The minimum inhibitory concentrations for amphotericin B, itraconazole and fluconazole ranged from 0.03125 to 0.5, 0.03125 to >16 and 0.125 to >64, respectively. Overall, 19 azole-resistant strains (14 C. tropicalis and 5 C. albicans) were found. Thus, this study shows that Testudines carry azole-resistant Candida spp.

Yeast microbiota of natural cavities of manatees (Trichechus inunguis and Trichechus manatus) in Brazil and its relevance for animal health and management in captivity.

The aim of this study was to characterize the yeast microbiota of natural cavities of manatees kept in captivity in Brazil. Sterile swabs from the oral cavity, nostrils, genital opening, and rectum of 50 Trichechus inunguis and 26 Trichechus manatus were collected. The samples were plated on Sabouraud agar with chloramphenicol and incubated at 25 °C for 5 days. The yeasts isolated were phenotypically identified by biochemical and micromorphological tests. Overall, 141 strains were isolated, of which 112 were from T. inunguis (Candida albicans, Candida parapsilosis sensu stricto, Candida orthopsilosis, Candida metapsilosis, Candida guilliermondii, Candida pelliculosa, Candida tropicalis, Candida glabrata, Candida famata, Candida krusei, Candida norvegensis, Candida ciferri, Trichosporon sp., Rhodotorula sp., Cryptococcus laurentii) and 29 were from T. manatus (C. albicans, C. tropicalis, C. famata, C. guilliermondii, C. krusei, Rhodotorula sp., Rhodotorula mucilaginosa, Rhodotorula minuta, Trichosporon sp.). This was the first systematic study to investigate the importance of yeasts as components of the microbiota of sirenians, demonstrating the presence of potentially pathogenic species, which highlights the importance of maintaining adequate artificial conditions for the health of captive manatees.

Virulence and antimicrobial susceptibility of clinical and environmental strains of Aeromonas spp. from northeastern Brazil.

The aims of the present study were to isolate and identify clinical and environmental strains of Aeromonas spp. by means of biochemical tests and the automated method VITEK 2 and to investigate the presence of the virulence genes cytotoxic enterotoxin (act), hemolysin (asa-1), and type III secretion system (ascV), and also the in vitro antimicrobial susceptibility of the strains. From the clinical isolates, 19 Aeromonas hydrophila, 3 Aeromonas veronii bv. sobria, and 1 Aeromonas caviae were identified, while from the environmental strains, 11 A. hydrophila, 22 A. veronii bv. sobria, 1 A. veronii bv. veronii, and 1 A. caviae were recovered. The gene act was detected in 69.5% of clinical isolates, asa-1 in 8.6%, and ascV in 34.7%. In the environmental strains, the detection rates were 51.4%, 45.7%, and 54.2% for the genes act, asa-1, and ascV, respectively. Resistance to amoxicillin-clavulanate and piperacillin-tazobactam was observed in 15 and 3 clinical strains, respectively, and resistance to ceftazidime, meropenem, imipenem, ciprofloxacin, and trimethoprim-sulfamethoxazole was observed in 1 strain for each drug. Resistance to amoxicillin-clavulanate and piperacillin-tazobactam was detected in 17 and 1 environmental strain, respectively. Higher resistance percentages were observed in clinical strains, but environmental strains also showed this phenomenon and presented a higher detection rate of virulence genes. Thus, it is important to monitor the antimicrobial susceptibility and pathogenic potential of the environmental isolates.

Simvastatin inhibits planktonic cells and biofilms of Candida and Cryptococcus species.

The antifungal activity of some statins against different fungal species has been reported. Thus, at the first moment, the in vitro antifungal activity of simvastatin, atorvastatin and pravastatin was tested against Candida spp. and Cryptococcus spp. Then, in a second approach, considering that the best results were obtained for simvastatin, this drug was evaluated in combination with antifungal drugs against planktonic growth and tested against biofilms of Candida spp. and Cryptococcus spp. Drug susceptibility testing was performed using the microdilution broth method, as described by the Clinical and Laboratory Standards Institute. The interaction between simvastatin and antifungals against planktonic cells was analyzed by calculating the fractional inhibitory concentration index. Regarding biofilm susceptibility, simvastatin was tested against growing biofilm and mature biofilm of one strain of each tested yeast species. Simvastatin showed inhibitory effect against Candida spp. and Cryptococcus spp. with minimum inhibitory concentration values ranging from 15.6 to 1000 mg L(-1) and from 62.5 to 1000 mg L(-1), respectively. The combination of simvastatin with itraconazole and fluconazole showed synergism against Candida spp. and Cryptococcus spp., while the combination of simvastatin with amphotericin B was synergistic only against Cryptococcus spp. Concerning the biofilm assays, simvastatin was able to inhibit both growing biofilm and mature biofilm of Candida spp. and Cryptococcus spp. The present study showed that simvastatin inhibits planktonic cells and biofilms of Candida and Cryptococcus species.