Nasopharyngeal carriage of Staphylococcus aureus among imprisoned males from Brazil without exposure to healthcare: risk factors and molecular characterization

Background: Previous studies report high prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) colonization among imprisoned populations. However, there are no data on that prevalence in Brazilian correctional institutions.Findings: We tested 302 male prisoners for nasopharyngeal colonization with Staphylococcus aureus from February 2009 through April 2010. The overall isolation rate of S. aureus was 16.5% (50/302). Men who had sex with men, users of inhalatory drugs and those with previous lung or skin diseases were more likely to be colonized with S. aureus. MRSA was isolated from 0.7% of subjects (2/302). The two Community-associated (CA)-MRSA belonged to ST5 but were unrelated based on the PFGE results. Both harbored SCCmec IV, and did not possess the Panton-Valentine Leukocidin gene.Conclusion: We found low prevalence of S. aureus and CA-MRSA among prisoners. MRSA isolates ST5 from two subjects harboured SCCmec IV and presented different PFGE patterns

Importância do Staphylococcus aureus nas mastites subclínicas: pesquisa de enterotoxinas e toxina do choque tóxico, e a relação com a contagem de células somáticas

Staphylococcus aureus is one of the major agents of contagious mastitis and has high incidence worldwide in most of dairy herds. Besides the economic impact, the public health aspects of the enterotoxins and the toxic shock syndrome toxin are very important. The enterotoxin A is frequently correlated with food related illness in man and can be associated with raw, pasteurized and other milk products. The toxic shock syndrome is caused most frequently by toxic shock syndrome toxin, but enterotoxins B and C also can be implicated. The aim of this study was to verify the occurrence of Staphylococcus aureus enterotoxins and toxic shock syndrome toxin producers. Milk samples from cows with clinical and subclinical mastitis were collected. The results of toxins research by "celofane over agar" to TNAase and by commercial kit to enterotoxins were associated with the electronic somatic cell count. Total of 209 milk samples from cows with clinical and subclinical mastitis caused by S.aureus were verified. A total of 209 (98.86%) were TNAase producers, nine samples (4.39%) were enterotoxin producers, and one of them (0.49%) was EED producer, three (1.46%) EEC producers and three (1.46%) EEB producers. The toxic shock syndrome toxin was not identified in any of the samples assayed on this study. There was no statistical correlation between the somatic cell count results and the samples with toxin production.O Staphylococcus aureus é um dos principais agentes das mastites consideradas contagiosas, apresentando elevada incidência na maioria dos rebanhos leiteiros em vários países. Além de perdas econômicas é importante salientar o aspecto de saúde pública para cepas produtoras de enterotoxinas e da toxina do choque tóxico. A enterotoxina A, relacionada com maior ênfase nos casos de toxinfecções alimentares, pode ser veiculada pelo leite cru, pasteurizado e subprodutos lácteos. A síndrome do choque tóxico é determinada mais freqüentemente pela toxina do choque tóxico, porém as enterotoxinas do tipo B e C também podem ser implicadas. O objetivo deste estudo foi verificar a ocorrência de S.aureus produtores de enteroxinas e da toxina do choque tóxico em amostras de leite de animais com mastite subclínica, e correlacionar estes resultados com a contagem de células somáticas; utilizando a técnica de "celofane over agar" para detecção da TNAase, kit comercial para identificação das enterotxinas e contagem eletrônica de células somáticas. Avaliod]MORENO, B.[u-se 209 amostras de leite oriundas de vacas com mastite subclínica por S.aureus, e dentre estas, 209 (98,86%) produziram TNAse, nove amostras (4,39%) foram produtoras de enterotoxinas, sendo que uma (0,49%) dentre elas foi produtora de EED, três (1,46%) de EEC, e três (1,46%) de EEB. Em uma amostra (0,49%), detectou-se concomitantemente EEA e EEB e em outra EEB e EEC. A toxina do choque tóxico não foi encontrada nas cepas avaliadas neste estudo, assim como não houve aumento estatisticamente significativo, na contagem de células somáticas, das amostras de cepas produtoras de enteroxinas

AVALIAÇÃO FENOTÍPICA E GENOTÍPICA DO PERFIL DE RESISTÊNCIA DE AMOSTRAS DE Staphylococcus aureus ISOLADAS DE CULTURAS CLÍNICAS E DE VIGILÂNCIA DE UM HOSPITAL DE ENSINO BRASILEIRO

Staphylococcus aureus pode causar uma variedade de infecções, principalmente nosocomiais. A sua importância reside na combinação da virulência, caráter invasivo e resistência aos antibióticos constituindo desafios terapêuticos. Este estudo objetivou avaliar fenotipica e genotipicamente o perfil de resistência de amostras de S. aureus isoladas de pacientes hospitalizados em um hospital de ensino brasileiro. Foram avaliadas 1078 amostras obtidas de culturas de vigilância e de amostras clínicas de S. aureus de pacientes internados no Hospital Estadual Bauru. Para avaliação do perfil fenotípico de resistência foi utilizado o método de disco-difusão conforme os critérios do CLSI, 2011. Para a determinação genotípica de resistência foi avaliada a presença do gene mecA pela Reação de Polimerase em Cadeia – PCR. Das 1078 amostras testadas fenotipicamente, foi observado que 75,1% das amostras eram Staphylococcus aureus resistente a Meticilina (MRSA), sendo que destes, 98.4% apresentaram resistência a oxacilina e 100%, a cefoxitina. Para a determinação genotípica foi realizada a técnica de PCR para amplificação do gene mecA. Das 443 amostras testadas para o gene mecA foram positivas 336 amostras (75.8%). Destas amostras, 85.7% apresentaram fenótipo de resistência a oxacilina e 88.4% a cefoxitina. Devido ao alto índice de MRSA, conclui-se a necessidade de investimento em pesquisas, racionalização do uso de antimicrobianos e criação de laboratórios de referência para verificação de resistência aos antimicrobianos

In vitro Effects of Antimicrobial Agents on Planktonic and Biofilm Forms of Staphylococcus saprophyticus Isolated From Patients With Urinary Tract Infections

Bacterial biofilms play an important role in urinary tract infections (UTIs), being responsible for persistent infections that lead to recurrences and relapses. Staphylococcus saprophyticus is one of the main etiological agents of UTIs, however, little is known about biofilm production in this species and especially about its response to the antimicrobial agents used to treat UTIs when a biofilm is present. For this reason, the aim of this work was to evaluate the response of S. saprophyticus biofilms to five antimicrobial agents. Staphylococcus saprophyticus was evaluated for antimicrobial susceptibility in its planktonic form by means of minimum inhibitory concentration (MIC) and in biofilms by means of minimum inhibitory concentration in biofilm (MICB) against the following antimicrobial agents by the microdilution technique: vancomycin, oxacillin, trimethoprim/sulfamethoxazole, ciprofloxacin, and norfloxacin. Of the 169 S. saprophyticus studied, 119 produced a biofilm as demonstrated by the polystyrene plate adherence method. Biofilm cells of S. saprophyticus exhibited a considerable increase in MICB when compared to the planktonic forms, with an increase of more than 32 times in the MICB of some drugs. Some isolates switched from the category of susceptible in the planktonic condition to resistant in the biofilm state. Statistical analysis of the results showed a significant increase in MICB (p < 0.0001) for all five drugs tested in the biofilm state compared to the planktonic form. Regarding determination of the minimum bactericidal concentration in biofilm (MBCB), there were isolates for which the minimum bactericidal concentration of all drugs was equal to or higher than the highest concentration tested

Immunization protected well nourished mice but not undernourished ones from lung injury in Methicillin-resistant Staphylococcus aureus (MRSA) infection

<p>Abstract</p> <p>Background</p> <p><it>Staphylococcus aureus </it>methicillin-resistant (MRSA) has been frequently isolated from endotracheal and lung puncture aspirates in malnourished children with pneumonia. In this work we evaluated the susceptibility of undernourished BALB/c mice and its ability to mount a protective immunity against MRSA with emphasis on the lung involvement.</p> <p>Results</p> <p>BALB/c mice submitted to a 20% dietary restriction during 20 days presented a significant decrease in body weight, lymphocyte number and also atrophy in thymus and intestinal epithelium. Determination of bacterial load by the number of colony forming units (CFU) indicated a similar susceptibility whereas the findings of Gram stain clearly suggested a higher amount of bacteria in the lungs of normal mice than in the undernourished ones. Immunization reduced bacterial growth in the lungs of normal mice but not in the undernourished ones. Histopathological analysis showed that inflammation appeared in the lungs from normal mice only after infection and that immunization prevented this pulmonary inflammatory process. On the other hand, undernourished mice presented lung inflammation even before infection. In addition, the degree of this inflammatory process did not change with infection or previous immunization.</p> <p>Conclusion</p> <p>Our results indicated that lung injury during MRSA infection is prevented by previous immunization in well nourished but not in undernourished mice.</p

Genes de enterotoxinas, multirresistência a antimicrobianos e caracterização molecular de espécies de Staphylococcus spp. isoladas de leite bovino orgânico

The multidrug resistant and the emergence of methicillin-resistant staphylococci isolated from animals, food, and humans are public health concern. These microorganisms produce different toxins related to food poisoning in humans. This study aimed to characterize Staphylococcus spp. isolated from two organic milk farms in Brazil. A total of 259 milk samples were collected, from which 58 (22.4%) Staphylococcus spp. were isolated. The highest sensibility to ceftiofur and sulfamethoxazole/trimethoprim was observed in 96.6% of Staphylococcus spp., and whereas 89% were resistant to penicillin G. The mecA gene was detected in 13.8% of the isolates. SEA and SEC were the most common enterotoxins detected. PFGE revealed genetic heterogeneity from S. intermedius and S. warneri analyzed, while S. aureus presented similar profiles among isolates from the two studied herds. To the best of our knowledge, the current study describes for the first time presence of enterotoxins, mecA gene, and genetic diversity of staphylococci isolated from organic dairy farms in Brazil.A emergência de estafilococos multirresistentes e resistentes à meticilina, isolados de animais, alimentos e humanos é uma preocupação em saúde pública. Esses micro-organismos produzem diferentes toxinas relacionadas à intoxicação alimentar em humanos. Este estudo caracterizou Staphylococcus spp. isolados em duas fazendas orgânicas no Brasil. Foram coletadas 259 amostras de leite em duas propriedades leiteiras orgânicas, nas quais 58 (22,4%) estirpes de Staphylococcus spp. foram isoladas. A maior sensibilidade dos isolados foi observada para ceftiofur e sulfametoxazol/trimetoprim em 96,6%. Em contraste, acima de 89% de resistência dos estafilicocos foi encontrada para penicilina G. O gene mecA foi identificado em 13,8% dos isolados. SEA e SEC foram as enterotoxinas mais comumente detectadas. PFGE revelou heterogeneidade genética entre S. intermedius e S. warneri, enquanto S. aureus demonstraram perfis semelhantes entre isolados dos dois rebanhos estudados. Relata-se pela primeira vez no Brasil a detecção de enterotoxinas, o gene mecA e diversidade genética em estafilococos isolados de vacas em produção orgânica

Safety issues of raw milk: evaluation of bacteriological and physicochemical characteristics of human milk from a bank in a teaching hospital, focusing on Staphylococcus species

Many infants are nurtured with milk supplied by human banks, whose bacteriological and physical-chemical profiles are a major issue. We investigated the bacteriological and physical-chemical characteristics, as well as genotypic and phenotypic and profiles of Staphylococcus species isolated from 240 samples of breast milk from a bank in a teaching hospital. Dornic acidity of milk revealed that 95.4% (229/240) had acceptable limits (&lt; 8.0 oD). Caloric intake showed a wide variation in cream content (4%), fat (4%) and energy values (559.81 Kcal/L). Staphylococcus (105/186 or 56.5%) and Enterobacter (25/186 or 13.4%) were the most prevalent genera, although other microorganisms were identified, including Klebsiella pneumoniae and Pseudomonas aeruginosa. Amoxicillin/clavulanic acid (125/157 or 79.6%), vancomycin (115/157 or 73.2%), and cephalexin (112/157 or 71.3%) were the most effective antimicrobials. High resistance rates of isolates were found to penicillin G (141/157 or 89.8%), ampicillin (135/157 or 86%), and oxacillin (118/157 or 75.2%). Multidrug resistance to ≥ 3 antimicrobials occurred in 66.2% (123/186) of the isolates. Residues of microbial multiplication inhibitory substances were found in 85% (204/240) of samples. Among the coagulase-positive-CPS and negative-CoNS staphylococci, the mecA gene was detected in 53.3% (8/15) and 75% (30/40), respectively. Genes sea, seb and sec were detected in 20% (3/15) of CPS, while tsst-1 was detected in 13.34% (2/15). In addition, 13.3% (2/15) of S. aureus were toxin-producers. Genes sea, seb and sec were detected in 90% (36/40), 5% (2/40) and 15% (6/40) CoNS, respectively. Enterotoxin production was identified in 5% (2/40) of CoNS. The identification of multidrug-resistant bacteria, staphylococci species toxin-producers harboring methicillin-resistance genes, and residues of microbial multiplication inhibitory substances reinforce the need for a continuous vigilance of milk quality offered to infant consumption by human banks