Characterization of Methicillin-resistant Staphylococcus aureus (MRSA) isolated in Santa Catarina (SC), Brazil.

The study investigated the characteristics of Methicillin-resistant Staphylococcus aureus (MRSA) isolated in Santa Catarina. Findings revealed prevalent SCCmecII and IV, multiresistance, Leucocidin ED genes, and one ST105 isolate. The results indicated that the in-state MRSA isolates showed the same characteristics as the out-of-state isolates among the investigated features.

Exploring the Bacteriome and Resistome of Humans and Food-Producing Animals in Brazil.

The epidemiology of antimicrobial resistance (AMR) is complex, with multiple interfaces (human-animal-environment). In this context, One Health surveillance is essential for understanding the distribution of microorganisms and antimicrobial resistance genes (ARGs). This report describes a multicentric study undertaken to evaluate the bacterial communities and resistomes of food-producing animals (cattle, poultry, and swine) and healthy humans sampled simultaneously from five Brazilian regions. Metagenomic analysis showed that a total of 21,029 unique species were identified in 107 rectal swabs collected from distinct hosts, the highest numbers of which belonged to the domain Bacteria, mainly Ruminiclostridium spp. and Bacteroides spp., and the order Enterobacterales. We detected 405 ARGs for 12 distinct antimicrobial classes. Genes encoding antibiotic-modifying enzymes were the most frequent, followed by genes related to target alteration and efflux systems. Interestingly, carbapenemase-encoding genes such as blaAIM-1, blaCAM-1, blaGIM-2, and blaHMB-1 were identified in distinct hosts. Our results revealed that, in general, the bacterial communities from humans were present in isolated clusters, except for the Northeastern region, where an overlap of the bacterial species from humans and food-producing animals was observed. Additionally, a large resistome was observed among all analyzed hosts, with emphasis on the presence of carbapenemase-encoding genes not previously reported in Latin America. IMPORTANCE Humans and food production animals have been reported to be important reservoirs of antimicrobial resistance (AMR) genes (ARGs). The frequency of these multidrug-resistant (MDR) bacteria tends to be higher in low- and middle-income countries (LMICs), due mainly to a lack of public health policies. Although studies on AMR in humans or animals have been carried out in Brazil, this is the first multicenter study that simultaneously collected rectal swabs from humans and food-producing animals for metagenomics. Our results indicate high microbial diversity among all analyzed hosts, and several ARGs for different antimicrobial classes were also found. As far as we know, we have detected for the first time ARGs encoding carbapenemases, such as blaAIM-1, blaCAM-1, blaGIM-2, and blaHMB-1, in Latin America. Thus, our results support the importance of metagenomics as a tool to track the colonization of food-producing animals and humans by antimicrobial-resistant bacteria. In addition, a network surveillance system called GUARANI, created for this study, is ready to be expanded and to collect additional data.

Genomic analysis of an extensively drug-resistant Pseudomonas aeruginosa ST312 harbouring IncU plasmid-mediated blaKPC-2 isolated from ascitic fluid.

OBJECTIVES: The Klebsiella pneumoniae carbapenemase (KPC) is disseminated worldwide mostly by plasmids. However, in Pseudomonas aeruginosa chromosomal mutations are more frequently responsible for resistance to carbapenems than the acquisition of mobile elements harbouring carbapenemases genes. Indeed, although uncommon, KPC-2-producing P. aeruginosa has appeared more frequently, including in Brazil. Here we report the first genomic analysis of a plasmid-mediated KPC-2 in an extensively drug-resistant (XDR) P. aeruginosa isolated in Santa Catarina, Brazil. METHODS: Antimicrobial susceptibility testing was performed according to CLSI 2020 guidelines. The genome was sequenced using an Illumina MiSeq platform and the data were analysed using SPAdes and Prokka. In silico predictions were fulfilled using curated bioinformatics tools. RESULTS: Pseudomonas aeruginosa strain MIMA_PA2.1 (JACGTM000000000) was classified as XDR, belongs to sequence type 312 (ST312) and harbours the blaKPC-2 gene located on a small (7975 bp) IncU plasmid. This plasmid showed 86.3% identity with a non-conjugative plasmid (KC609322) carrying the blaKPC-2 gene from a multidrug-resistant P. aeruginosa (ST1006) from Colombia isolated in 2006. Besides the blaKPC-2 gene, other resistance genes to ß-lactams, aminoglycosides, phenicol, fosfomycin and quinolones were detected, the last two also associated with mobile genetic elements other than the IncU plasmid described here. CONCLUSION: This is the first genomic report of the presence of the blaKPC-2 gene carried by Pseudomonas in Southern Brazil and highlights the adaptability of blaKPC-2 to different mobile elements. This draft genome might be useful for comparative genomic analyses to monitor the spread of plasmid-mediated blaKPC in P. aeruginosa in Latin America.

Impacto do microbioma na COVID-19 / Impact of the microbiome on COVID-19

Inúmeros estudos demonstram o papel da microbiota intestinal na aquisição e evolução do SARS-CoV-2. Atua diretamente inibindo a replicação viral, assim como indiretamente modulando a resposta imune. Alguns perfis bacterianos já foram associados com uma maior gravidade dos sintomas, baseado na já bem conhecida conexão intestino-pulmão,com a produção de metabólitos bacterianos e componentes da resposta imune. Sem dúvida, o intestino pode ser alvo de futuras intervenções, através de modulação intestinal,propiciando uma nova e promissora abordagem no manejo terapêutico dos pacientes comCOVID-19.

Numerous studies demonstrate the role of the intestinal microbiota in the acquisition and evolution of SARS-CoV-2. It acts directly by inhibiting viral replication, as well as indirectly modulating the immune response. Some bacterial profiles have already been associated with a greater severity of symptoms, based on the well-known intestinelung connection, with the production of bacterial metabolites and components of the immune response. Undoubtedly, the intestine can be the target of future interventions, through intestinal modulation, providing a new and promising approach in the therapeutic management of patients with COVID-19

First case report of non-human primates (Alouatta clamitans) with the hypervirulent Klebsiella pneumoniae serotype K1 strain ST 23: A possible emerging wildlife pathogen.

BACKGROUND: Hypervirulent strain of Klebsiella pneumoniae genotype K1 isolates have recently emerged, causing severe pyogenic liver abscess complicated by devastating metastatic infections in humans. METHODS: We describe a short outbreak of the non-human primate (NHP) research center, associated with a hypervirulent K. pneumoniae. The genetic similarity of the strains was evaluated by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) techniques, and virulence encoding genes were detected by polymerase chain reaction (PCR). RESULTS: The isolates were phenotypically like strains causing community-acquired invasive liver abscess syndrome in humans. All strains exhibited identical PFGE patterns and were found to belong to ST23 and presented a hypermucovisity phenotype and possessed magA and rmpA gene. CONCLUSION: This is the first case report of NHPs caused by K. pneumoniae displaying a hypermucoviscosity phenotype and belonging to capsular serotypes K1 and ST23.

Molecular epidemiology of heteroresistant vancomycin-intermediate Staphylococcus aureus in Brazil

ABSTRACTTo determine the epidemiological and molecular characteristics of 12 Staphylococcus aureus isolates presenting heteroresistance to vancomycin in laboratories of two cities in Santa Catarina, southern Brazil. Epidemiological data, including the city of isolation, health institution, and date of isolation were considered, as well as the associated clinical specimen. For molecular characterization, we analyzed the staphylococcal cassette chromosome types, the erm gene presence, and the genomic diversity of isolates using pulsed-field gel electrophoresis. The 12 isolates of S. aureus were previously confirmed as heteroresistance to vancomycin using the population analysis profile-area under curve. Regarding genetic variability, two clones were detected: the main one (clone A) composed of four isolates and the clones B, with two isolates. For clone A, two isolates presented identical band patterns and were related to the same hospital, with an interval of 57 days between their isolation. The other isolates of this clone showed no epidemiological link between them because they were isolated in different hospitals and had no temporal relationship. The other clone showed no detectable epidemiological relationship. The heteroresistance to vancomycin recovered in Santa Catarina State from 2009 to 2012 had, in general, heterogeneous genomic patterns based on pulsed-field gel electrophoresis results, which is in accordance with the fact that these isolates had little or no epidemiological relationship among them. Due to the characteristic phenotypic instability and often prolonged vancomycin therapy for selection, clonal spread is not as common as for other resistance mechanisms disseminated through horizontal gene transfer.

Molecular epidemiology of heteroresistant vancomycin-intermediate Staphylococcus aureus in Brazil.

To determine the epidemiological and molecular characteristics of 12 Staphylococcus aureus isolates presenting heteroresistance to vancomycin in laboratories of two cities in Santa Catarina, southern Brazil. Epidemiological data, including the city of isolation, health institution, and date of isolation were considered, as well as the associated clinical specimen. For molecular characterization, we analyzed the staphylococcal cassette chromosome types, the erm gene presence, and the genomic diversity of isolates using pulsed-field gel electrophoresis. The 12 isolates of S. aureus were previously confirmed as heteroresistance to vancomycin using the population analysis profile-area under curve. Regarding genetic variability, two clones were detected: the main one (clone A) composed of four isolates and the clones B, with two isolates. For clone A, two isolates presented identical band patterns and were related to the same hospital, with an interval of 57 days between their isolation. The other isolates of this clone showed no epidemiological link between them because they were isolated in different hospitals and had no temporal relationship. The other clone showed no detectable epidemiological relationship. The heteroresistance to vancomycin recovered in Santa Catarina State from 2009 to 2012 had, in general, heterogeneous genomic patterns based on pulsed-field gel electrophoresis results, which is in accordance with the fact that these isolates had little or no epidemiological relationship among them. Due to the characteristic phenotypic instability and often prolonged vancomycin therapy for selection, clonal spread is not as common as for other resistance mechanisms disseminated through horizontal gene transfer.

Complete Genome Sequence of Staphylococcus aureus FCFHV36, a Methicillin-Resistant Strain Heterogeneously Resistant to Vancomycin.

We report here the sequence of the entire chromosome of Staphylococcus aureus strain FCFHV36, a methicillin-resistant strain heterogeneously intermediate to vancomycin, bearing a type II staphylococcal chromosome cassette mec element (SCCmec), belonging to multilocus sequence type (MLST) 105, and isolated from a vertebra of a patient with osteomyelitis.

Evaluation of mtthods in detecting vancomycin mc among mrsa isolates and the cchanges in accuracy related to different mic values / Avaliação de métodos na detecção da MIC de vancomicina e mudanças na acurácia relacionada a diferentes valores de MIC

INTRODUCTION: Methicillin-Resistant Staphylococcus aureus (MRSA) presenting reduced susceptibility to vancomycin has been associated to therapeutic failure. Some methods used by clinical laboratories may not be sufficiently accurate to detect this phenotype, compromising results and the outcome of the patient. OBJECTIVES: To evaluate the performance of methods in the detection of vancomycin MIC values among clinical isolates of MRSA. MATERIAL AND METHODS: The Vancomycin Minimal Inhibitory Concentration was determined for 75 MRSA isolates from inpatients of Mãe de Deus Hospital, Porto Alegre, Brazil. The broth microdilution (BM) was used as the gold-standard technique, as well as the following methods: E-test® strips (BioMérieux), M.I.C.E® strips (Oxoid), PROBAC® commercial panel and the automated system MicroScan® (Siemens). Besides, the agar screening test was carried out with 3 µg/mL of vancomycin. RESULTS: All isolates presented MIC ≤ 2 µg/mL for BM. E-test® had higher concordance (40%) in terms of global agreement with the gold standard, and there was not statistical difference among E-test® and broth microdilution results. PROBAC® panels presented MICs, in general, lower than the gold-standard panels (58.66% major errors), while M.I.C.E.® MICs were higher (67.99% minor errors). CONCLUSIONS: For the population of MRSA in question, E-test® presented the best performance, although with a heterogeneous accuracy, depending on MIC values.

INTRODUÇÃO: Staphylococcus aureus resistente à meticilina (MRSA) apresentando suscetibilidade reduzida à vancomicina tem sido associado à falha terapêutica. Alguns métodos utilizados por laboratórios clínicos podem não ser suficientemente precisos para detectar este fenótipo, comprometendo os resultados e o desfecho do paciente. OBJETIVOS: Avaliar o desempenho de métodos na detecção dos valores de MIC de vancomicina entre isolados clínicos de MRSA. MATERIAIS E MÉTODOS: Determinamos a Concentração Inibitória Mínima de Vancomicina para 75 MRSA isolados de pacientes do Hospital Mãe de Deus, Porto Alegre, Brasil. Utilizamos a microdiluição em caldo como técnica padrão-ouro e os seguintes métodos: tiras de E-test® (BioMérieux), tiras M.I.C.E® (Oxoid), painel comercial da PROBAC® e sistema automatizado MicroScan® (Siemens). Além disso, foi realizado o teste de triagem em ágar com 3 µg/mL de vancomicina. RESULTADOS: Todos os isolados apresentaram MIC ≤ 2 µg/mL. Não houve diferença estatística entre os resultados do E-test® e da microdiluição em caldo. O painel da PROBAC® apresentou MICs, em geral, menores que o padrão-ouro (58,66% de erros maiores), enquanto que as MICs pelo M.I.C.E.® foram maiores (67,99% de erros menores). CONCLUSÕES: Para nossa população de MRSA, E-test® apresentou o melhor desempenho, embora com uma acurácia heterogênea, dependendo dos valores da MIC.

Evaluation of methods in detecting vancomycin MIC among MRSA isolates and the changes in accuracy related to different MIC values.

INTRODUCTION: Methicillin-Resistant Staphylococcus aureus (MRSA) presenting reduced susceptibility to vancomycin has been associated to therapeutic failure. Some methods used by clinical laboratories may not be sufficiently accurate to detect this phenotype, compromising results and the outcome of the patient. OBJECTIVES: To evaluate the performance of methods in the detection of vancomycin MIC values among clinical isolates of MRSA. MATERIAL AND METHODS: The Vancomycin Minimal Inhibitory Concentration was determined for 75 MRSA isolates from inpatients of Mãe de Deus Hospital, Porto Alegre, Brazil. The broth microdilution (BM) was used as the gold-standard technique, as well as the following methods: E-test® strips (BioMérieux), M.I.C.E® strips (Oxoid), PROBAC® commercial panel and the automated system MicroScan® (Siemens). Besides, the agar screening test was carried out with 3 µg/mL of vancomycin. RESULTS: All isolates presented MIC ≤ 2 µg/mL for BM. E-test® had higher concordance (40%) in terms of global agreement with the gold standard, and there was not statistical difference among E-test® and broth microdilution results. PROBAC® panels presented MICs, in general, lower than the gold-standard panels (58.66% major errors), while M.I.C.E.® MICs were higher (67.99% minor errors). CONCLUSIONS: For the population of MRSA in question, E-test® presented the best performance, although with a heterogeneous accuracy, depending on MIC values.

Is prediffusion test an alternative to improve accuracy in screening hVISA strains and to detect susceptibility to glycopeptides/lipopeptides?

The characterization of heteroresistant vancomycin-intermediate Staphylococcus aureus strains (hVISA) is even more challenging, as no routine standardized laboratory methods are available. A total of 124 S. aureus isolates recovered from inpatients attended in hospitals of Santa Catarina State, Southern Brazil, were evaluated. The MIC of vancomycin, teicoplanin, and daptomycin was determined by Etest and prediffusion tests using NeoSensitabs® tablets. All isolates were susceptible to vancomycin (MICs: 0.5-3 µg/mL) by Etest. However, according to prediffusion test, 17 isolates presented reduced susceptibility to vancomycin, and of these, 12 were confirmed as hVISA using populational analysis. Considering daptomycin, prediffusion results were in agreement with susceptibility data (MICs), as all isolates were susceptible. Considering that characterizing hVISA is challenging and that MIC determination is not adequate to characterize this phenotype, prediffusion test was a viable alternative to screening hVISA and reduced susceptibility to vancomycin. It was simple and low cost, with accuracy comparable to other well-established methods.

Role of gastric mucus secretion, oxinitrergic system and sulfhydryl groups on the gastroprotection elicited by Polygala cyparissias (Polygalaceae) in mice.

OBJECTIVES: This study has aimed to assess the mechanisms of action for the gastroprotective effect of the acetone extract (PCAE) and methanol fraction (PCMF) of Polygala cyparissias, as well as to evaluate the activity of 1,3,6,8-tetrahydroxy-2,7-dimethoxyxanthone (1), 1,7-dihydroxy-2,3-dimethoxyxanthone (2) and astragalin (3). METHODS: Gastric secretion and mucus content were determined by pylorus ligation in mice. Nitric oxide (NO) and sulfhydryl group participation were observed by the pretreatment of mice with L-NAME or NEM. Acute ulcer was induced by ethanol/HCl and chronic ulcer by acetic acid. Anti-Helicobacter pylori activity was evaluated by the agar solid dilution assay. KEY FINDINGS: Neither PCAE nor PCMF had the ability to reduce H(+) concentration. However, both of them enhanced mucus secretion. PCAE demonstrated its gastroprotection in a NO-dependent manner, while PCMF exerted the activity depending on the sulfhydryl group. In chronic ulcer, the curative ratios for the PCAE and PCMF were 67.5 and 58.4%, respectively. No effect over H. pylori was detected. Compounds 1, 2 and 3 were able to reduce lesions in the order of 79.6, 73.8 and 67.6%, respectively. CONCLUSIONS: The data suggested that PCAE and PCMF displayed antiulcer activity due to different mechanisms and with the participation of phenolic compounds obtained from the plant.

Staphylococcus lugdunensis: um olhar diferenciado no laboratório clínico / Staphylococcus lugdunensis: a different view in the clinical laboratory

Os estafilococos coagulase negativos (ECNs) são cocos Gram-positivos usualmente considerados contaminantes em laboratórios de microbiologia clínica. Apesar de pertencer a este grupo, Staphylococcus lugdunensis pode causar infecções complicadas, como endocardites, infecções de pele e tecidos moles, osteomielites, entre outras. Além da formação de biofilmes, apresenta patogenicidade similar ao Staphylococcus aureus. É um dos principais agentes causadores de endocardites, com taxa de mortalidade de até 70 por cento. Pode ser confundido com S. aureus quando se utilizam testes rápidos para sua identificação, como a pesquisa de clumping factor, no caso de teste de coagulase em lâmina, ou em testes de aglutinação direta em látex. Pode ser facilmente identificado por meio de provas bioquímicas acessíveis, como a presença de atividade da ornitina descarboxilase e pirrolidonil arilamidase (PYR). Apresenta sensibilidade à maioria dos agentes antimicrobianos, devendo ser pesquisada rotineiramente a presença de betalactamases e do gene mecA por meio de testes com cefalosporina cromogênica e suscetibilidade à cefoxitina, respectivamente. Convém salientar que os critérios interpretativos utilizados para avaliar a sensibilidade à cefoxitina são os mesmos preconizados para S. aureus e diferentes dos utilizados para os outros ECNs. Apesar de incomum, o S. lugdunensis é um patógeno com acentuada virulência que deve ser corretamente identificado, pois raramente poderá ser considerado contaminante quando isolado de sítios estéreis.

Coagulase-negatives staphylococci (CNS) are Gram-positives cocci commonly regarded as contaminants in clinical microbiology laboratories. Despite belonging to this group, Staphylococcus lugdunensis may cause complicated infections such as endocarditis, skin infections and soft tissue, osteomyelitis, among others. Apart from the formation of biofilms, it has pathogenic features similar to Staphylococcus aureus. It may be mistakenly identified as S. aureus when using rapid identification tests, such as clumping factor in slide coagulase or in agglutination latex tests. It is easily identified through available biochemical tests, such as the presence of ornithine decarboxylase and pyrrolidonyl arylamidase (PYR). It presents sensitivity to most antimicrobial agents. Furthermore, the presence of beta-lactamase and mecA gene should be routinely investigated by testing with chromogenic cephalosporin and cefoxitin susceptibility, respectively. It is convenient to highlight that the interpretative criteria used to evaluate cefoxitin sensitivity are the same recommended for S. aureus and different from those used for other CNS. Despite the fact it is atypical, S. lugdunensis is a virulent pathogen, which must be accurately identified insofar as it will rarely be deemed as a contaminant when isolated from sterile sites.

Prevalence of carbapenem resistant Pseudomonas aeruginosa and Acinetobacter baumannii in high complexity hospital

Pseudomonas aeruginosa and Acinetobacter baumannii are Gram-negative bacilli that in the last decades have become prevalent agents of hospital infection due to high antimicrobial resistance developed by these microorganisms. The present study is a retrospective analysis of all positive cultures for these microorganisms in the period of January 2004 to December 2008. Resistance levels of A. baumannii and P. aeruginosa to carbapenems was high and showed a trend to increase during the period of study. In recent years the increasing incidence and resistance levels of A. baumannii and P. aeruginosa to the antimicrobials used for their treatment in the hospital setting underscores the relevance of infections caused by these bacteria. The selective pressure caused by indiscriminated use of broad-spectrum antibiotics in empirical hospital infections is probably the main reason for such an increase with the consequent impact upon patient morbidity and mortality.

Quando e como valorizar culturas de urina polimicrobianas no laboratório de microbiologia clínica / When and how to enhance polymicrobial urine cultures at the laboratory of clinical microbiology

INTRODUÇÃO: Na maioria dos laboratórios de Microbiologia considera-se contaminação uma cultura de urina com mais de um morfotipo colonial, ignorando-se o desenvolvimento ou solicitando-se novo material. Raramente o isolado é considerado significativo. OBJETIVOS: Com a finalidade de estudar as infecções urinárias polimicrobianas, no período de agosto de 2003 a janeiro de 2004, na cidade de Tubarão, Santa Catarina, foram selecionadas 117 amostras de urina de pacientes internados no Hospital Nossa Senhora da Conceição, de ambos os sexos, com idades que variavam de 14 a 98 anos. MÉTODOS: Realizou-se uma análise minuciosa dos prontuários dos pacientes. Procedeu-se o Gram da gota de urina não centrifugada e a cultura com alça calibrada de 1 ou 10 μl em ágar CLED (cistina-lactose deficiente em eletrólitos). Todas as culturas foram repetidas com nova coleta de urina com supervisão direta. Os clínicos aguardaram a segunda coleta (confirmatória) para iniciar a antibioticoterapia. Descartaram-se os pacientes que iniciaram a antibioticoterapia imediatamente após a primeira coleta ou que estavam utilizando antimicrobianos. RESULTADOS: Obteve-se o total de seis (12,8 por cento) culturas polimicrobianas confirmadas, em um universo de 47 amostras com crescimento bacteriano estudadas. Os resultados foram compatíveis com as indicações clínicas. CONCLUSÃO: É importante ressaltar a correlação entre os achados laboratoriais e as indicações clínicas dos pacientes. Recomenda-se avaliar criteriosamente isolados polimicrobianos em amostras de urina, sejam ambulatoriais ou hospitalares.

INTRODUCTION: In most microbiology laboratories, a urine culture is regarded as contaminated when there is more than one colonial morphotype, thus either it is ignored or a new sample is requested. The isolate is rarely considered significant. OBJECTIVES: In order to study the polymicrobial urinary tract infections, 117 urine samples were selected from inpatients of both genders aged from 14 to 98 years old at Nossa Senhora da Conceição Hospital, Tubarão city, Santa Catarina, Brazil, from August 2003 to January 2004. METHODS: A detailed analysis of patients' records was carried out. Gram test of non-centrifuged urine drop and culture with calibrated loop of 1 or 10 microliters in CLED agar were performed. All cultures were repeated with new urine collection under direct supervision. Physicians waited for the second collection (confirmatory test) to initiate antibiotic therapy. Patients that had started antibiotic therapy immediately after the first collection or those that were using antibiotics were discarded. RESULTS: Six polymicrobial cultures were confirmed from a total of 47 samples with bacterial growth. The results were consistent with clinical indications. CONCLUSION: It is important to emphasize the correlation between laboratory findings and patients' clinical indications. It is recommended that polymicrobial isolates in urine samples from both out-patients and inpatients should be thoroughly investigated.

A Gardnerella vaginalis e as infecções do trato urinário / The Gardnerella vaginalis and the urinary tract infections

As infecções do trato urinário (ITUs) estão entre as mais frequentes nos seres humanos. São causadas por grande variedade de uropatógenos habituais, porém podem ser provocadas por alguns micro-organismos fastidiosos, como a Gardnerella vaginalis, que é uma bactéria anaeróbia facultativa, observada sob a forma de cocobacilos Gram-variáveis. Ela habita a mucosa vaginal e eventualmente pode ocasionar ITUs. O isolamento pode ser realizado em amostras de urina utilizando o ágar CNA (colistina e ácido nalidíxico), com incubação de 48 a 72 horas em atmosfera rica em CO2. O exame de Gram de urina não centrifugada pode auxiliar o microbiologista na identificação das amostras nas quais uma bactéria fastidiosa seja o agente causal, já que a visualização de inúmeras células epiteliais, a ausência de leucócitos e a presença de mais de um tipo morfológico sugerem contaminação da amostra. Como estudos comprovam a incidência de G. vaginalis entre os agentes causadores de ITUs, o isolamento em uroculturas não deve ser desprezado. A interpretação clínica do crescimento da G. vaginalis é de difícil avaliação, sendo imprescindível a troca de informações entre o laboratório de microbiologia clínica e a equipe médica, investigando a presença de sinais e sintomas que possam estar associados à ITU.

Urinary tract infections are among the most recurrent in human beings. They are caused by a wide variety of usual uropathogens, although they may be caused by some fastidious micro-organisms, such as Gardnerella vaginalis. It is a facultative anaerobe, found in the form of Gram-variable coccobacilli. It inhabits the vaginal mucosa and occasionally may cause urinary tract infections. The isolation may be performed on urine samples using CNA agar, incubated for 48-72 hours in atmosphere rich in CO2. The Gram examination of non-centrifuged urine may aid the microbiologist in identifying samples in which a fastidious bacterium is the causative agent, since the visualization of numerous epithelial cells, the absence of leukocytes and the presence of more than one morphological type suggest sample contamination. As studies show the Gardnerella vaginalis incidence among the causative agents of urinary tract infections, the isolation in urine cultures can not be overlooked. The clinical interpretation of the Gardnerella vaginalis growth is difficult to assess, thus being essential the information exchange between the clinical microbiology laboratory and medical staff in order to investigate the presence of signs and symptoms that may be associated with urinary tract infections.

Prevalence of carbapenem resistant Pseudomonas aeruginosa and Acinetobacter baumannii in high complexity hospital.

Pseudomonas aeruginosa and Acinetobacter baumannii are Gram-negative bacilli that in the last decades have become prevalent agents of hospital infection due to high antimicrobial resistance developed by these microorganisms. The present study is a retrospective analysis of all positive cultures for these microorganisms in the period of January 2004 to December 2008. Resistance levels of A. baumannii and P. aeruginosa to carbapenems was high and showed a trend to increase during the period of study. In recent years the increasing incidence and resistance levels of A. baumannii and P. aeruginosa to the antimicrobials used for their treatment in the hospital setting underscores the relevance of infections caused by these bacteria. The selective pressure caused by indiscriminated use of broad-spectrum antibiotics in empirical hospital infections is probably the main reason for such an increase with the consequent impact upon patient morbidity and mortality.