Microbiological analysis of oral biofilms in patients admitted to intensive care unit: Pilot study.

AIM: To identify Pseudomonas aeruginosa and Staphylococcus aureus in oral biofilms of intubated and non-intubated patients admitted to an Intensive Care Unit (ICU). METHODS: This was a cross-sectional study, with 30 biofilm sites sampled. S. aureus and P. aeruginosa were identified by conventional biochemical assays. Antimicrobial susceptibility was tested by disk-diffusion. RESULTS: Of 30 sites, 50% contained P. aeruginosa and 3.33% S. aureus. P. aeruginosa was detected in similar amounts in all 3 sample sites, with 5 colonized sites (50%). S. aureus colonized a single supragingival site (3.33%). There was resistance to multiple antimicrobial agents of P. aeruginosa in 7 sites (100%) and S. aureus in 1 (100%). CONCLUSIONS: This study revealed an important relationship between P. aeruginosa and S. aureus colonization at supragingival, subgingival and lingual sites and intubation, thus revealing antimicrobial resistant bacteria colonization of medical interest, which may contribute to the therapy choice directed to these microorganisms.

Cellular Growth Arrest and Efflux Pumps Are Associated With Antibiotic Persisters in Streptococcus pyogenes Induced in Biofilm-Like Environments.

Streptococcus pyogenes (group A Streptococcus-GAS) is an important pathogen for humans. GAS has been associated with severe and invasive diseases. Despite the fact that these bacteria remain universally susceptible to penicillin, therapeutic failures have been reported in some GAS infections. Many hypotheses have been proposed to explain these antibiotic-unresponsive infections; however, none of them have fully elucidated this phenomenon. In this study, we show that GAS strains have the ability to form antimicrobial persisters when inoculated on abiotic surfaces to form a film of bacterial agglomerates (biofilm-like environment). Our data suggest that efflux pumps were possibly involved in this phenomenon. In fact, gene expression assays by real-time qRT-PCR showed upregulation of some genes associated with efflux pumps in persisters arising in the presence of penicillin. Phenotypic reversion assay and whole-genome sequencing indicated that this event was due to non-inherited resistance mechanisms. The persister cells showed downregulation of genes associated with protein biosynthesis and cell growth, as demonstrated by gene expression assays. Moreover, the proteomic analysis revealed that susceptible cells express higher levels of ribosome proteins. It is remarkable that previous studies have reported the recovery of S. pyogenes viable cells from tissue biopsies of patients presented with GAS invasive infections and submitted to therapy with antibiotics. The persistence phenomenon described herein brings new insights into the origin of therapeutic failures in S. pyogenes infections. Multifactorial mechanisms involving protein synthesis inhibition, cell growth impairment and efflux pumps seem to play roles in the formation of antimicrobial persisters in S. pyogenes.

Ocorrência de Staphylococcus spp. resistente à meticilina em otite externa canina / Occurrence of methicillin-resistant Staphylococcus spp. in canine external otitis

Objetivo: O presente estudo objetivou traçar o perfil de resistência dos isolados de Staphylococcus spp. resistentes à meticilina (SMR) em cães com otite externa proveniente de atendimentos ambulatoriais ou de internação. Métodos: Isolamento e identificação bacteriológica por meio de provas bioquímicas e testes de susceptibilidade a antibacterianos. Detecção do gene mecA por PCR e determinação da concentração bactericida mínima (CBM) ao gluconato de clorexidina. Resultados: Foram coletadas 140 amostras e, destas, foram isolados 122 Staphylococcus spp. (49,4%). Dos isolados bacterianos, 14 cepas (11,47%) foram SMR (oito coagulase positiva e seis coagulase negativa), apresentando o gene mecA. A concentração bactericida mínima ao gluconato de clorexidina para os Staphylococcus spp. coagulase positiva foi de 500.000 mg/mL (0,5%) e para os coagulase negativa foi de 62.500 mg/mL (0,0625%). Cinco SMR foram positivos para o teste-D. Os SMR foram 100% sensíveis à linezolida, cloranfenicol e rifampicina. Conclusão: Apesar da baixa frequência da multirresistência encontrada, existe a necessidade de monitoramento efetivo em estirpes isoladas de animais domésticos, garantindo o sucesso do tratamento e controle da resistência bacteriana em infecções otológicas caninas.

Objective: The objective of this study is to outline the resistance profile of methicillin-resistant Staphylococcus spp. (MRS) isolates from outpatient and inpatient care dogs diagnosed with otopathy. Methods: Isolation and bacteriological identification through biochemical tests and antibacterial susceptibility testing. Detection of mecA gene by PCR and determination of minimum bactericidal concentration (CBM) to chlorhexidine gluconate. Results: 140 samples were collected and from these 122 was Staphylococcus spp. (49.4%). Of all bacterial isolates 14 (11.47%) were MRS (eight coagulase positive and six coagulase negative) with mecA gene. The minimum bactericidal concentration to chlorhexidine guconate was 500,000 mg/mL (0.5%) for coagulase positive Staphylococcus spp. and 62,500 mg/mL (0.0625%) for coagulase negative. Five MRS were positive for D-test. The MRS were 100% sensitive to linezolide, chloramphenicol and rifampicin. Conclusion: Despite the low frequency of multiressitance found, there is a need for more effective monitoring in strains isolated from domestic animals to guarantee successful treatment and control of bacterial resistance in canine otological infections.

Decreased susceptibility to chlorhexidine and distribution of qacA/B genes among coagulase-negative Staphylococcus clinical samples.

BACKGROUND: Healthcare-associated infection (HAI) is a major public health problem. As a form of prevention and control, preparations of chlorhexidine are used extensively; however, the reduction of susceptibility to chlorhexidine has been reported. The aim of this study was to investigate the susceptibility to chlorhexidine and the distribution of the qacA/B genes in 211 clinical isolates of coagulase-negative Staphylococci (CoNS). METHODS: CoNS were identified by conventional biochemical tests. Antimicrobial susceptibility was tested by disk-diffusion. Minimum inhibitory concentration (MIC) of chlorhexidine was determined by agar dilution test; detection of the qacA/B and mecA genes were evaluated by PCR. RESULTS: The most frequently isolated species were S. epidermidis, S. hominis hominis, S. auricularis, and S. haemolyticus, respectively. The strains presented a multidrug resistance profile of 87%, including methicillin resistance. Reduced susceptibility to chlorhexidine was observed in 31%. The qacA/B genes were detected in samples resistant (32/32) and susceptible (17/32) to chlorhexidine. The vast majority (94%) of the samples with reduced susceptibility to chlorhexidine were multidrug resistant. CONCLUSIONS: Our results show that qacA/B genes are not restricted to strains expressing chlorhexidine resistance. Further studies are needed to understand how the expression of these genes occurs.

Crude extract and fractions from Eugenia uniflora Linn leaves showed anti-inflammatory, antioxidant, and antibacterial activities.

BACKGROUND: This study showed phytochemical composition and evaluates the anti-inflammatory, and analgesic activities of crude extract (CE) and fractions from E. uniflora Linn leaves. METHODS: Polyphenols present in crude extract (CE), in aqueous fraction (AqF), and ethyl acetate (EAF) treated fractions from E. uniflora Linn leaves were shown by chromatographic analysis in order to conduct a phytochemical characterization. Antibacterial activity was evaluated based on minimum inhibitory concentrations (MICs) determined using the agar dilution method. Doses of 50, 100, and 200 mg/kg of the CE and fractions were applied for conducting in vivo models (male Swiss mice, 8-10 weeks old). The peritonitis experimental model was induced by carrageenan following of Myeloperoxidase activity (MPO), Total glutathione and malondialdehyde (MDA), IL-1ß and TNF-α levels by spectroscopic UV/VIS analysis. Antinociceptive activity was evaluated based on an abdominal writhing model and hot plate test. The results were statistically evaluated using one-way analysis of variance (ANOVA), followed by Bonferroni's post-hoc test. The level of statistical significance was p < 0.05. RESULTS: High-performance liquid chromatography with photodiode array detection (HPLC-DAD) detected varying concentrations of gallic acid, ellagic acid, and myricitrin in the CE and fractions obtained from E. uniflora Linn leaves (0.05-0.87%w/w, 0.20-0.32%w/w, and 1.71-6.56%w/w, respectively). In general, the CE had lower MIC values than the fractions, including the lowest MIC against the MRSA strain. The CE and AqF also significantly reduced leukocyte migration and MPO activity (p < 0.05). In addition, AqF significantly reduced IL-1ß and TNF-α levels (p < 0.05). Furthermore, the CE and fractions exhibited an antioxidant effect (p < 0.05) and peripheral analgesic activity (p < 0.05). CONCLUSIONS: The CE and fractions from the studied E. uniflora Linn leaves exhibited antibacterial, anti-inflammatory, antioxidant, and analgesic activity in the performed assays.

Evaluation of microbiological, cellular and risk factors associated with subclinical mastitis in female buffaloes.

OBJECTIVE: This study aimed to evaluate the microbiological and cellular milk profile for the diagnosis of subclinical mastitis in female buffaloes and to assess risk factors for predisposition of the disease. METHODS: Analyses were carried out by standard plate count (SPC), identification of species and antibiotic resistance, somatic cell count (SCC), electrical electrical conductivity of milk (ECM), and lactoferrin content in milk. Teat cups were swabbed to evaluate risk factors, observing hyperkeratosis, milking vacuum pressure and cleanliness of the site. Hence, 30 female buffaloes were randomly selected (15 from a group in early lactation and 15 in late lactation). RESULTS: The most common bacteria in the microbiological examination were Staphylococcus spp., Streptococcus spp. and Corynebacterium sp. In the antibiotic sensitivity test, 10 (58.82%) of the 17 antibiotics tested were sensitive to all isolates, and resistant bacteria were Streptococcus uberis, Streptococcus dysgalactiae, Streptococcus haemolyticus, and Escherichia coli. It was observed that positive samples in the microbiological examination showed total bacterial count between 9.10×103 to 6.94×106 colony forming units/mL, SCC between 42,000 to 4,320,000 cells/mL and ECM ranging from 1.85 to 7.40 mS/cm. It was also found that the teat cups had high microbial counts indicating poor hygiene, and even faults in the cleanliness of the animals' waiting room were observed. It is concluded that values of SCC above 537,000 cells/mL and ECM above 3.0 mS/mL are indications of mammary gland infection for this herd; however, the association of these values with a microbiological analysis is necessary to more accurately evaluate the health status of mammary glands with subclinical mastitis. CONCLUSION: Through phenotypic characterization of bacteria involved in the samples, the genera Staphylococcus spp., Streptococcus spp., and Corynebacterimum bovis were the most prevalent in this study. Faults in environment and equipment hygienization are factors that are directly associated with mastitis.

Enterotoxin-Encoding Genes in Staphylococcus spp. from Food Handlers in a University Restaurant.

Food handlers carrying enterotoxin-producing Staphylococcus are a potential source of food poisoning. The aim of this study was to analyze genes encoding enterotoxins in coagulase-positive Staphylococcus (CoPS) and coagulase-negative Staphylococcus (CoNS) isolated from the anterior nostrils and hands of food handlers at a university restaurant in the city of Natal, Northeast Brazil. Thirty food handlers were screened for the study. The isolates were subjected to Gram staining, a bacitracin sensitivity test, mannitol fermentation, and catalase and coagulase tests. CoNS and CoPS strains were subsequently identified by a Vitek 2 System (BioMerieux, France) and various biochemical tests. Polymerase chain reaction was used to detect genes for enterotoxins A, B, C, D, E, G, H, and I (sea, seb, sec, sed, see, seg, seh, and sei) and a disc-diffusion method was used to determine susceptibility to several classes of antimicrobials. All food handlers presented staphylococci on their hands and/or noses. The study found 58 Staphylococcus spp., of which 20.7% were CoPS and 79.3% were CoNS. S. epidermidis was the most prevalent species. Twenty-nine staphylococci (50%) were positive for one or more enterotoxin genes, and the most prevalent genes were seg and sei, each with a frequency of 29.3%. Indeed, CoNS encoded a high percentage of enterotoxin genes (43.5%). However, S. aureus encoded even more enterotoxin genes (75%). Most isolates showed sensitivity to the antibiotics used for testing, except for penicillin (only 35% sensitive). The results from this study reinforce that coagulase-negative as well as coagulase-positive staphylococci isolated from food handlers are capable of genotypic enterotoxigenicity.

Emergence of methicillin-resistant coagulase-negative staphylococci resistant to linezolid with rRNA gene C2190T and G2603T mutations.

The aim of this article were to determinate the mechanism of linezolid resistance in coagulase-negative methicillin-resistant staphylococci from hospitals in the northeast of Brazil. We identified the isolates using VITEK(®) 2 and MALDI-TOF. Susceptibility to antibiotics was measured by the disk-diffusion method and by Etest(®) . Extraction of the whole genome DNA was performed, followed by screening of all the strains for the presence of mecA and cfr genes. The domain V region of 23S rRNA gene was sequenced and then aligned with a linezolid-susceptible reference strain. Pulsed-field gel electrophoresis (PFGE) macro-restriction analysis was performed. Three linezolid-resistant Staphylococcus hominis and two linezolid-resistant Staphylococcus epidermidis strains were analyzed. The isolates showed two point mutations in the V region of the 23S rRNA gene (C2190T and G2603T). We did not detect the cfr gene in any isolate by PCR. The S. hominis showed the same pulsotype, while the S. epidermidis did not present any genetic relation to each other. In conclusion, this study revealed three S. hominis and two S. epidermidis strains with resistance to linezolid due to a double mutation (C2190T and G2603T) in the domain V of the 23S rRNA gene. For the first time, the mutation of C2190T in S. epidermidis is described. This study also revealed the clonal spread of a S. hominis pulsotype between three public hospitals in the city of Natal, Brazil. These findings highlight the importance of continued vigilance of linezolid resistance in staphylococci.

Prevalence of subgingival Staphylococcus at periodontally healthy and diseased sites.

Staphylococci are considered members of the transient oral microbiota and are seldom isolated from the oral cavity. The aim of this study was to establish the prevalence of subgingival staphylococci in healthy and periodontal disease sites. Sterile endodontic paper points were used to isolate subgingival staphylococci in periodontally healthy and periodontally diseased sites in 30 adult subjects (n=540 sites). Staphylococcus spp were identified by an automated method and confirmed by conventional biochemical tests. All the samples were identified as coagulase-negative staphylococci. The results were analyzed using Mann-Whitney U, chi-square and Fisher's exact test at 5% significance level. A total of 86.7% of the subjects harbored these microorganisms in 11.7% of their periodontal sites. The most frequently isolated species was S. auricularis, which was isolated from 31.4% of the periodontal sites, followed by S. epidermidis, isolated from 21.4% of them. There was no statistically significant difference between the frequencies of these species isolated either from the healthy and the diseased sites (p>0.153). Although staphylococci are present in the subgingival environment and contribute to the pathogenic synergism involved in periodontal diseases, the results suggest that they do not participate directly in the pathogenesis of these diseases.

Quantification of polyphenols and evaluation of antimicrobial, analgesic and anti-inflammatory activities of aqueous and acetone-water extracts of Libidibia ferrea, Parapiptadenia rigida and Psidium guajava.

ETHNOPHARMACOLOGICAL RELEVANCE: Vast numbers of plant species from northeastern Brazil have not yet been phytochemically or biologically evaluated. AIM OF THE STUDY: The goal of this work was to obtain, characterize and show the antimicrobial, analgesic and anti-inflammatory activities of aqueous and acetone-water extracts of Libidibia ferrea, Parapiptadenia rigida and Psidium guajava. MATERIALS AND METHODS: The plant material (100g) was dried, and the crude extracts were obtained by using turbo-extraction (10%; w/v) with water or acetone:water (7:3, v/v) as the extraction solvent. High-performance liquid chromatography (HPLC) methods were used to screen the crude extracts for hydrolysable tannins (gallic acid) and condensed tannins (catechins). The antibacterial activity was evaluated by agar-diffusion and microdilution methods against Gram-positive strains (Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis INCQS 00016, Enterococcus faecalis ATCC 29212 and a clinical isolate of methicillin-resistant Staphylococcus aureus) as well as Gram-negative strains (Escherichia coli ATCC 25922, Salmonella enteritidis INCQS 00258, Shigella flexneri and Klebsiella pneumoniae). To evaluate the anti-inflammatory activity, a leukocyte migration model was used. Analgesic activity was determined by the hot plate test and the acetic acid-induced abdominal writhing test. Data were analyzed by analysis of variance (ANOVA) at a significance level of 5%. RESULTS: Parapiptadenia rigida presented the highest amount of total polyphenols (35.82 ± 0.20%), while the greatest catechin content was found in the acetone-water extract of Psidium guajava (EAWPg; 1.04 µg/g). The largest amounts of catechins were found in the aqueous extract of Libidibia ferrea (EALf; 1.07 µg/g) and the acetone-water extract of Parapiptadenia rigida (EAWPr; 1.0 µg/g). All extracts showed activity against Gram-positive bacteria. The aqueous and acetone-water extracts of Psidium guajava showed the greatest inhibition zones in the agar diffusion tests. In the evaluation of the minimum inhibitory concentration (MIC), the most susceptible Gram-positive bacterium was Staphylococcus epidermidis and the most susceptible Gram-negative bacterium was Shigella flexneri. EAPg and EAWPg showed the greatest MIC values. All extracts were significant inhibitors of leukocyte migration (p<0.05). Using the writhing test, significant analgesic activity was found for EAPr (50 mg/kg), EAWPr (100 mg/kg and 200 mg/kg) and EAWPg (50 mg/kg) (p<0.05). CONCLUSIONS: Thus, the appropriate extraction procedure preserves the chemical components such as gallic acid and catechin, and showed antimicrobial, anti-inflammatory and analgesic properties.

Chromobacterium violaceum: um caso fatal no nordeste do Brasil / Chromobacterium violaceum: a fatal case in the northeast of the Brazil

Chromobacterium violaceum is a rare pathogen that can potentially cause fatal infections in humans. An 8-year-old child from Natal, northeast of Brazil, presented history of fever, sore throat, and abdominal pain, during 5 days before admission, and died 4 hours after hospitalization. Chromobacterium violaceum was isolated from oropharynx scrapings and was resistant to ampicillin, cefotaxime, cefalotin, ceftazidime, and ceftriaxone...

Chromobacterium violaceum é um patógeno raro que potencialmente pode causar infecções fatais em humanos. Relatamos o caso de uma criança de 8 anos de idade, moradora da cidade de Natal, nordeste do Brasil, que apresentou história de febre, dor na garganta e no abdome durante os cinco dias anteriores à internação, e veio a falecer após 4 horas de hospitalização. A bactéria Chromobacterium violaceum foi isolada da orofaringe e apresentou resistência a ampicilina, cefotaxima, cefalotina, ceftazidima e ceftriaxona...

Colonização nasal por Staphylococcus sp. em pacientes internados / Nasal colonization by Staphylococcus sp. in inpatients

Objetivo Analisar a colonização nasal por Staphylococcus sp., sua resistência à meticilina e fatores associados em pacientes internados.Métodos Foram realizados coleta de amostra nasal, testes de susceptibilidade antimicrobiana e análise de prontuários médicos de pacientes internados (n=71), e foi aplicado um questionário. Os dados foram analisados por meio de estatística descritiva e inferencial usando os testes c2, t de Student e Mann-Whitney (α=5%).Resultados Cerca de metade (44,4%) dos pacientes, significativamente associados ao tratamento antibiótico prolongado (p=0,02) estavam infectados por Staphylococcus sp resistentes à meticilina. Observou-se uma associação significativa entre pacientes com cepas sensíveis e ausência de tratamento com antibiótico antes da coleta (p=0,02) ou ausência de feridas (p=0,003).Conclusão Foram encontradas cepas de Staphylococcus sp. resistentes à meticilina e não houve diferença significativa entre a espécie S. aureus e os grupos de estafilococos coagulase negativos, o que indica o grau de disseminação da resistência à meticilina entre diferentes espécies de Staphylococcus.

Objective To analyze nasal colonization by Staphylococcus sp. its resistance to methicillin, and associated factors in inpatients.Methods Nasal sample collection, antimicrobial susceptibility tests, and analysis of medical records of inpatients (n=71) were performed, and a questionnaire was applied. Data were analyzed by descriptive and inferential statistics using the chi-square, Student’s t, and Mann-Whitney tests (α=5%).Results Nearly half (44.4%) of the patients who were significantly associated with prolonged antibiotic treatment (p=0.02) was infected with methicillin-resistant Staphylococcus sp.. A significant association was observed between patients with sensitive strains and absence of antibiotic treatment prior to sample collection (p=0.02) or absence of wounds (p=0.003).Conclusion Strains of methicillin-resistant Staphylococcus sp. were found, and there was no significant difference between the S. aureus species and the coagulase-negative Staphylococci groups, which indicates the degree of spread of methicillin resistance among different species of Staphylococcus.

Prevalence and factors associated with wound colonization by Staphylococcus spp. and Staphylococcus aureus in hospitalized patients in inland northeastern Brazil: a cross-sectional study.

BACKGROUND: Infections by Staphylococcus spp. are often associated with wounds, especially in hospitalized patients. Wounds may be the source of bacteria causing cross-contamination, and are a risk factor for methicillin-resistant Staphylococcus aureus (MRSA) infection. The aim of this study was to investigate the prevalence of wound colonization by Staphylococcus spp., especially S. aureus and MRSA, in hospitalized patients, and to identify the factors associated with such colonization. METHODS: This cross-sectional study enrolled patients with wounds who were hospitalized in a remote and underdeveloped inland region of northeastern Brazil with extreme poverty. Samples were collected using sterile swabs with 0.85% saline solution, and coagulase-negative Staphylococcus spp., S. aureus, and MRSA were identified using standard laboratory procedures. Data regarding the sociodemographic characteristics, antibiotic use, and comorbidities of the patients were collected using the medical records and a questionnaire. RESULTS: A total of 125 wounds were analyzed. The patients had a mean age of 63.88 years and a mean 3.84 years of school education. Eighty-one wounds (64.80%) were colonized by Staphylococcus spp. Twenty-five wounds (20%) were colonized by S. aureus, 32% of which were colonized by MRSA. Wound colonization by Staphylococcus spp. was associated with pneumonia or other respiratory disease (p = 0.03). Wound colonization by S. aureus was associated with nasal colonization by S. aureus (p < 0.001), fewer days of prior antibiotic use (p = 0.04), admission to a medical ward (p = 0.02), and age >65 years (p = 0.05). Among patients with wound colonization by MRSA, 37.50% had a history of prior antibiotic use, 75% had two or more comorbidities, 25% had cancer or diabetes, 50% had cardiovascular disease, and 50% died. CONCLUSIONS: Wounds can be the source of Staphylococcus spp. infection, and high proportions of wounds are colonized by S. aureus and MRSA. Nasal colonization by S. aureus may be a source for wound colonization by S. aureus, illustrating the importance of preventing cross-contamination in hospital environments, especially among elderly patients. Wounds should be carefully managed to prevent microbial spread, thereby assisting patient recovery and reducing healthcare costs.

Feature selection strategies for identification of Staphylococcus aureus recovered in blood cultures using FT-IR spectroscopy successive projections algorithm for variable selection: a case study.

Staphylococcus aureus is one of the leading causes of bacteremia, with high levels of accompanying morbidity and mortality. Current gold standard for the detection of S. aureus is very time-consuming, typically taking 24h or longer. We set out to determine whether Fourier-transform infrared spectroscopy (FT-IR) combined with variable selection techniques, such as, genetic algorithm-linear discriminant analysis (GA-LDA) and successive projection algorithm-linear discriminant analysis (SPA-LDA) could be applied to detect this pathogen of bloodstream infection in samples based on the unique spectral "fingerprints" of their biochemical composition. Thirty real blood samples from healthy volunteers were contaminated with five different concentrations (10(7) until 10(3) CFU/mL) of microorganism and it analyzed by IR spectroscopy. The resulting GA-LDA model successfully classified all test samples with respect to their concentration in contaminated blood using only 18 wavenumbers. Discriminant functions revealed that GA-LDA clearly segregated different microorganism concentrations and the variable selected confirmed the chemical entities associated with the microorganism. The current study indicates that IR spectroscopy with feature selection techniques have the potential to provide one rapid approach for whole-organism fingerprint diagnostic microbial directly in blood culture.

Prevalence of Subgingival Staphylococcus at Periodontally Healthy and Diseased Sites

Staphylococci are considered members of the transient oral microbiota and are seldom isolated from the oral cavity. The aim of this study was to establish the prevalence of subgingival staphylococci in healthy and periodontal disease sites. Sterile endodontic paper points were used to isolate subgingival staphylococci in periodontally healthy and periodontally diseased sites in 30 adult subjects (n=540 sites). Staphylococcus spp were identified by an automated method and confirmed by conventional biochemical tests. All the samples were identified as coagulase-negative staphylococci. The results were analyzed using Mann-Whitney U, chi-square and Fisher's exact test at 5% significance level. A total of 86.7% of the subjects harbored these microorganisms in 11.7% of their periodontal sites. The most frequently isolated species was S. auricularis, which was isolated from 31.4% of the periodontal sites, followed by S. epidermidis, isolated from 21.4% of them. There was no statistically significant difference between the frequencies of these species isolated either from the healthy and the diseased sites (p>0.153). Although staphylococci are present in the subgingival environment and contribute to the pathogenic synergism involved in periodontal diseases, the results suggest that they do not participate directly in the pathogenesis of these diseases.

Os estafilococos são considerados membros da microbiota oral transiente e são pouco isolados da cavidade oral. O objetivo deste estudo foi estabelecer a prevalência de estafilococos subgengivais em sítios saudáveis e com doença periodontal. Pontas endodônticas de papel absorvente estéreis foram usadas para isolar estafilococos subgengivais de sítios periodontais doentes e saudáveis, em 30 indivíduos adultos (n=540 sítios). Os Staphylococcus spp foram identificados por método automatizado e confirmados por provas bioquímicas convencionais. Todas as amostras foram identificadas como estafilococos coagulase-negativa. Os resultados foram analisados através dos testes de Mann-Whitney U, Qui-quadrado ou Exato de Fisher para um nível de significância de 5%. Um total de 86,7% dos indivíduos albergavam estes microrganismos em 11,7% de seus sítios periodontais. A espécie mais frequentemente isolada foi S. auricularis, a qual foi isolada em 31.4% dos sítios periodontais, seguida pela espécie S. epidermidis, isolada de 21.4% dos sítios. Não houve associação significativa na freqüência de isolamento das espécies, seja nos sitios periodontais saudáveis ou doentes (p>0.153). Embora os estafilococos estejam presentes no ambiente subgengival e contribuam para o sinergismo patogênico envolvido em doenças periodontais, sugere-se que eles não participem diretamente na patogênese destas doenças.

Potencial antimicrobiano dos antissépticos de uso popular anapyon®, água rabelo® e malvatricin® sobre microrganismos do meio ambiente oral / Antimicrobial Potential of the Popular Antiseptics Anapyon®, Água Rabelo® and Malvatricin® against Oral Microorganisms

Objetivo: Verificar, ?in vitro?, o potencial antimicrobiano do Anapyon®, da Água Rabelo® e do Malvatricin® sobre microrganismos presentes na cavidade oral.Método: Para realização do experimento, utilizou-se o protocolo sequenciado durante quatro dias que avaliou, através da medida da densidade óptica, o potencial antimicrobiano dos fármacos nos microrganismos (Staphylococcus aureus, Candida tropicalis, Candida parapsilosis e Candida albicans), em suas formas planctônicas, apenas o Malvatricin® foi avaliado sobre as formas de biofilme por ser o único fármaco que apresentou resultados satisfatórios sobre as formas planctônicas. O estudo adotou como controle negativo a água destilada e controle positivo a Clorexidina®. Os resultados obtidos foram submetidos a uma análise estatística com os testes de Kruskal-Wallis e Mann-Whitney. Resultados: Observou-se, através da medida da densidade óptica, que apenas o Malvatricin® apresentou bons resultados na forma planctônica, sendo estes semelhantes ao controle positivo (clorexidina), considerado padrão nos ensaios antimicrobianos em Odontologia. Os resultados do Malvatricin® foram estatisticamente melhores quando comparados aos demais fármacos (Anapyon®, Água Rabelo®) e ao controle negativo. Este resultado foi semelhante para todos os microrganismos estudados: Staphylococcus aureus (p=0,002), Candida tropicalis (p=0,002), Candida parapsilosis (p=0,001) e Candida albicans (p<0,001). Desta forma, apenas o Mavatricin® foi testado para o microrganismo arranjado em biofilme. Observou-se, então, que para a C.albicans e para o S. aureus, houve diferença significativa entre clorexidina e Malvatricin® (p<0,05), com melhores resultados para o clorexidina. Para C. tropicalis, o Malvatricin® diferiu significativamente (p<0,05) da água destilada. Em relação a C.parapsilosis, nenhuma diferença foi observada em relação ao controle negativo (p=0,468). Conclusão: Apesar de alguns fármacos alternativos serem tidos como antimicrobianos, tais propriedades sobre células planctônicas e, principalmente, sobre biofilme foram observadas apenas para o Malvatricin®.

Objective: To evaluate in vitro the antimicrobial potential of Anapyon®, Água Rabelo and Malvatricin® against oral microorganisms.Method: The experiment used a four-day sequential protocol that evaluated by optical density measurements the antimicrobial potential of these products against Staphylococcus aureus, Candida tropicalis, Candida parapsilosis and Candida albicans in their planktonic forms. Only Malvatricin® was also evaluated against microbial biofilms because it was the only one to produce satisfactory results against the planktonic forms. Distilled water was used as negative control and Chlorhexidine® as positive control. The data were analyzed statistically by the Kruskal-Wallis and Mann-Whitney tests. Results: According to the optical density readings, only Malvatricin® was effective against the planktonic microorganisms and its results were similar to those of the positive control (Chlorhexidine), which is the gold standard antimicrobial agent in dental research. Malvatricin® presented significantly higher efficacy than the other antiseptics (Anapyon® and Água Rabelo®) and the negative control, and this result was similar for all tested microorganisms: S. aureus (p=0.002), C tropicalis (p=0.002), C. parapsilosis (p=0.001) and C. albicans (p<0.001). For this reason, only Malvatricin® was evaluated against the microorganisms arranged as biofilms. Chlorhexidine presented significantly better results (p<0.05) than Malvatricin® against C. albicans and S. aureus. When tested against C. tropicalis, Malvatricin® differed significantly (p<0.05) from distilled water, while against C. parapsilosis no significant difference (p=0.468) was observed in comparison with the negative control. Conclusion: Although some pharmaceutical products being considered anti-microbial, such properties against planktonic cells and especially the biofilms were observed only for Malvatricin®.

The use of near infrared spectroscopy and multivariate techniques to differentiate Escherichia coli and Salmonella Enteritidis inoculated into pulp juice.

This study shows the application and usefulness of near infrared (NIR) transflectance spectra measurements in the identification and classification of Escherichia coli and Salmonella Enteritidis from commercial fruit pulp (pineapple). Principal component analysis (PCA), soft independent modeling of class analogy (SIMCA) analysis and partial least-squares discriminant analysis (PLS-DA) were used in the analysis. It was not possible to obtain total separation between the samples using PCA and SIMCA. PLS-DA presented good performance achieving prediction ability of 87.5% for E. coli and 88.3% for S. Enteritidis, respectively. For the best models, the sensitivity and specificity was 0.87 and 0.83 for PLS-DA with second derivative spectra. These results suggest that NIR spectroscopy and PLS-DA can be used to discriminate and detect bacteria in fruit pulp for modeling linear class boundaries.

Frequência e perfil de resistência de Klebsiella spp. em um hospital universitário de Natal/RN durante 10 anos / Frequence and resistance profile of Klebsiella spp. isolates in a university hospital in Natal/RN during a ten-year period

INTRODUÇÃO: As espécies de Klebsiella spp. podem causar vários tipos de infecções, principalmente hospitalares, e têm merecido destaque pelos seus variados e emergentes mecanismos de resistência. OBJETIVOS: Determinar a frequência de isolamento e a caracterização do perfil de resistência de Klebsiella spp. em um hospital universitário durante um período de 10 anos e, ainda, avaliar a tendência para o crescimento dessa resistência. Material e método: Fez-se um estudo descritivo e retrospectivo a partir de dados coletados nos livros de registro do Laboratório de Microbiologia Clínica do hospital investigado, correspondentes ao período de janeiro de 1999 a dezembro de 2008. RESULTADO: A frequência de isolamento de Klebsiella spp. foi de 13,4 por cento com predominância em uroculturas (56,4 por cento). Houve aumento significativo na resistência para a maioria dos antimicrobianos testados ao longo do período analisado com tendência para o crescimento da mesma. Nesse período, isolou-se 23 por cento de Klebsiella spp. com fenótipo produtor de betalactamases de amplo espectro (ESBL). DISCUSSÃO: O isolamento de Klebsiella spp. resistente a antimicrobianos em amostras de origem clínica e a detecção da tendência do crescimento da resistência, inclusive às drogas de reserva terapêutica, são motivos de grande preocupação. Nesse hospital, a implantação de métodos de triagem e de confirmatórios para os mecanismos de resistência de Klebsiella spp. poderiam auxiliar no diagnóstico e no tratamento das infecções causadas por esse microrganismo. CONCLUSÃO: A tendência de crescimento na resistência aos antibióticos detectada neste estudo reforça a importância de monitoramentos contínuos. Estes elucidam características locais, orientando para melhores medidas de controle.

INTRODUCTION: Klebsiella spp. species can cause several infections, particularly nosocomial ones. Furthermore, its multiple emerging resistance mechanisms have been widely described. OBJECTIVES: To determine the isolation frequency and resistance profile of Klebsiella spp. at a university hospital during a ten-year period as well as to assess the increase in its resistance. Material and method: A retrospective and descriptive study was carried out based on data collected from the record books of the Laboratory of Clinical Microbiology of the investigated Hospital from January 1999 to December 2008. RESULTS: The isolation frequency of Klebsiella spp. was 13.4 percent, predominantly in urine cultures (56.4 percent). There was a significant increase in resistance to most antimicrobials tested over the analyzed period; 23 percent of Klebsiella spp. with ESBL phenotype was isolated over this period. DISCUSSION: Multi-resistant Klebsiella spp. isolates from clinical samples as well as its growing trend in resistance mechanisms, including to reserve drugs, are cause for great concern. The implementation of screening and confirmatory methods of bacterial resistance could aid in the diagnosis and treatment of infections caused by this microorganism. CONCLUSION: The increase in resistance to antibiotics reinforces the importance of continuous monitoring, which elucidates local characteristics and allows more suitable control measures.

Evaluation of different methods for detecting methicillin resistance in staphylococcus aureus isolates in a university hospital located in the northeast of Brazil

Many methods have been described for the detection of methicillin-resistant Staphylococcus aureus (MRSA), but the heterogeneous expression of methicillin resistance affects the reliability of these methods. The aim of the present study was to evaluate some methods for detecting methicillin resistance in Staphylococcus aureus isolates in a university hospital located in the Northeast of Brazil. Among the isolates, 15 were methicillin-susceptible and 45 were methicillin-resistant, including low-level heterogeneous resistance strains. Both the 30 µg-cefoxitin disk and PBP2a test had 100 percent sensibility/specificity and appear to be good options for the detection of MRSA in the clinical laboratory.

Evaluation of different methods for detecting methicillin resistance in Staphylococcus aureus isolates in a university hospital located in the Northeast of Brazil.

Many methods have been described for the detection of methicillin-resistant Staphylococcus aureus (MRSA), but the heterogeneous expression of methicillin resistance affects the reliability of these methods. The aim of the present study was to evaluate some methods for detecting methicillin resistance in Staphylococcus aureus isolates in a university hospital located in the Northeast of Brazil. Among the isolates, 15 were methicillin-susceptible and 45 were methicillin-resistant, including low-level heterogeneous resistance strains. Both the 30 ηg-cefoxitin disk and PBP2a test had 100% sensibility/specificity and appear to be good options for the detection of MRSA in the clinical laboratory.