Characterization of Escherichia coli obtained from patients undergoing peritoneal dialysis and diagnosed with peritonitis in a Brazilian centre.

Purpose. This study aimed to characterize 27 Escherichia coli isolates obtained from peritoneal dialysis (PD)-related peritonitis that occurred at the University Hospital of Botucatu Medical School, Brazil, between 1997 and 2015.Methodology. These isolates were characterized regarding the occurrence of 22 virulence factor-encoding genes, antimicrobial resistance and biofilm production. We then evaluated whether these factors influenced the clinical outcome.Results. Over an 18-year period, 726 episodes of PD-related peritonitis were diagnosed, with 27 of them (3.7 %) being due to E. coli. The majority of the isolates were classified in phylogroups B1 (33.3 %), B2 (30.0 %) or F (18.0 %). fimH (100.0 %), ompT (66.7 %) and irp2 (51.9 %) were the most prevalent genes, while papA, papC, iha, sat, irp2, iucD, ireA, ibe10, ompT and kpsMTII were significantly more prevalent among isolates belonging to phylogroups B2 and F (P<0.05). Non-susceptibility to quinolones was detected in six isolates, which harboured chromosomal and/or plasmid-mediated quinolone resistance determinants, while two CTX-M extended-spectrum ß-lactamase-producing E. coli were identified. Virulence factor-encoding genes (alone or in combination) and antimicrobial resistance were not associated with non-resolution outcomes. However, there was a trend for the ability to produce biofilm to be associated with treatment failure, although this association was not statistically significant.Conclusion. The E. coli isolates were heterogeneous in terms of the features investigated, and were susceptible to most of the antimicrobial drugs tested, despite the unsuccessful treatment observed in more than 50.0 % of the patients. Studies including more cases could help to clarify if biofilm production can influence the outcome in patients with PD-related peritonitis.

Peritoneal dialysis-related peritonitis due to Staphylococcus aureus: a single-center experience over 15 years.

Peritonitis caused by Staphylococcus aureus is a serious complication of peritoneal dialysis (PD), which is associated with poor outcome and high PD failure rates. We reviewed the records of 62 S. aureus peritonitis episodes that occurred between 1996 and 2010 in the dialysis unit of a single university hospital and evaluated the host and bacterial factors influencing peritonitis outcome. Peritonitis incidence was calculated for three subsequent 5-year periods and compared using a Poisson regression model. The production of biofilm, enzymes, and toxins was evaluated. Oxacillin resistance was evaluated based on minimum inhibitory concentration and presence of the mecA gene. Logistic regression was used for the analysis of demographic, clinical, and microbiological factors influencing peritonitis outcome. Resolution and death rates were compared with 117 contemporary coagulase-negative staphylococcus (CoNS) episodes. The incidence of S. aureus peritonitis declined significantly over time from 0.13 in 1996-2000 to 0.04 episodes/patient/year in 2006-2010 (p = 0.03). The oxacillin resistance rate was 11.3%. Toxin and enzyme production was expressive, except for enterotoxin D. Biofilm production was positive in 88.7% of strains. The presence of the mecA gene was associated with a higher frequency of fever and abdominal pain. The logistic regression model showed that diabetes mellitus (p = 0.009) and ß-hemolysin production (p = 0.006) were independent predictors of non-resolution of infection. The probability of resolution was higher among patients aged 41 to 60 years than among those >60 years (p = 0.02). A trend to higher death rate was observed for S. aureus episodes (9.7%) compared to CoNS episodes (2.5%), (p = 0.08), whereas resolution rates were similar. Despite the decline in incidence, S. aureus peritonitis remains a serious complication of PD that is associated with a high death rate. The outcome of this infection is negatively influenced by host factors such as age and diabetes mellitus. In addition, ß-hemolysin production is predictive of non-resolution of infection, suggesting a pathogenic role of this factor in PD-related S. aureus peritonitis.

Peritonitis in recent years: clinical findings and predictors of treatment response of 170 episodes at a single Brazilian center.

PURPOSE: Peritonitis continues to be a major cause of dropout in peritoneal dialysis (PD) patients. Changes in the prevalence of peritonitis etiologies and an increase in the frequency of methicillin-resistant coagulase-negative staphylococci (CoNS) and Gram-negative species resistant to commonly used antibiotics have been reported. As a consequence, the current clinical presentation and patient outcome may differ from classical descriptions. The objectives of this study were to describe the clinical and microbiological characteristics of PD-related peritonitis episodes that occurred over a period of 6 years at a single Brazilian dialysis center and to identify predictors of outcome. METHODS: A total of 170 peritonitis episodes that occurred in 92 PD patients between January 2004 and December 2009 were reviewed. Multivariate analysis was used to identify demographic, clinical, and microbiological factors predicting endpoints (resolution and peritonitis-related death). Patients' characteristics and peritonitis incidence, etiology and outcomes were compared with a series of 232 episodes that occurred in the first 6 years (1995-2000) of the PD program at the same center. RESULTS: The overall peritonitis rate was 0.65 episodes/patient-year. Gram-positive cocci were identified in 79 (46.5%) episodes, whereas Gram-negative bacilli were isolated from 48 (28.2%). CoNS were the main Gram-positive species identified in 48 episodes. Of these, 56.3% were resistant to methicillin. Among Gram-negative species, amikacin resistance was observed in 60% of non-fermentative Gram-negative bacilli (NFGNB) and in only 3.6% of Enterobacteriaceae. The overall resolution rate was 44.1%. Oxacillin resistance and NFGNB etiology were strong predictors of non-resolution, whereas older age was the only predictor of death. Antibiotic protocols did not influence outcome. Comparison with the results obtained for the 1990-1995 period showed a lower peritonitis rate, a strong decline in the proportion of Staphylococcus aureus episodes, a significant increase in the frequency of oxacillin-resistant CoNS and amikacin-resistant NFGNB, and a significantly lower resolution and higher death rate. CONCLUSIONS: The current clinical characteristics and outcome suggest a greater severity of peritonitis episodes and higher risk of death, possibly due to bacterial resistance. Older age is a risk factor for death.

The role of virulence factors in the outcome of staphylococcal peritonitis in CAPD patients.

BACKGROUND: Peritonitis continues to be the most frequent cause of peritoneal dialysis (PD) failure, with an important impact on patient mortality. Gram-positive cocci such as Staphylococcus epidermidis, other coagulase-negative staphylococci (CoNS), and Staphylococcus aureus are the most frequent etiological agents of PD-associated peritonitis worldwide. The objective of the present study was to compare peritonitis caused by S. aureus and CoNS and to evaluate the factors influencing outcome. METHODS: Records of 86 new episodes of staphylococcal peritonitis that occurred between 1996 and 2000 in the Dialysis unit of a single university hospital were studied (35 due to S. aureus, 24 to S. epidermidis and 27 to other CoNS). The production of slime, lipase, lecithinase, nuclease (DNAse), thermonuclease (TNAse), alpha- and beta-hemolysin, enterotoxins (SEA, SEB, SEC, SED) and toxic shock syndrome toxin-1 (TSST-1) was studied in S. aureus and CoNS. Antimicrobial susceptibility was evaluated based on the minimal inhibitory concentration determined by the E-test. Outcome predictors were evaluated by two logistic regression models. RESULTS: The oxacillin susceptibility rate was 85.7% for S. aureus, 41.6% for S. epidermidis, and 51.8% for other CoNS (p = 0.001). Production of toxins and enzymes, except for enterotoxin A and alpha-hemolysin, was associated with S. aureus episodes (p < 0.001), whereas slime production was positive in 23.5% of CoNS and 8.6% of S. aureus strains (p = 0.0047). The first model did not include enzymes and toxins due to their association with S. aureus. The odds of resolution were 9.5 times higher for S. epidermidis than for S. aureus (p = 0.02) episodes, and were similar for S. epidermidis and other CoNS (p = 0.8). The resolution odds were 68 times higher for non-slime producers (p = 0.001) and were not influenced by oxacillin resistance among vancomycin-treated cases (p = 0.89). In the second model, the resolution rate was similar for S. aureus and S. epidermidis (p = 0.70), and slime (p = 0.001) and alpha-hemolysin (p = 0.04) production were independent predictors of non-resolution. CONCLUSION: Bacterial species and virulence factors rather than antibiotic resistance influence the outcome of staphylococcal peritonitis.

Bacteriúria em pacientes com diabetes mellitus / Bacteriuria in patients with diabetes mellitus

Realizamos o presente trabalho com o objetivo de compreender melhor a associaçäo: diabetes mellitus e infecçäo urinária (IU). Trezentos e dezesseis diabéticos (88 por cento ambulatoriais) fortam acompanhados por um período de um a oito anos. Verificou-se prevalência de 24,7 por cento de bacteriúria significativa (BS>- 105 germes/ml): 32,3 por cento entre mulheres e 13,4 por cento entre os homens. Ambos os grupos de diabéticos, com e sem BS, caracterizaram-se por terem 40 ou mais anos de idade, serem diabéticos näo-insulinodependentes e portadores das complicaçöes crônicas. Ainda näo diferiram quanto ao tempo e grau de controle da doenca. Entretanto, no grupo com BS houve maior número de pacientes internados e com outros fatores predisponentes: hiperplasia prostática, cistocele, calculose renal. Os agentes etiológicos mais frequentes foram E.coli e Klebsiella pneumoniae (61, 6 por cento e 15,2 por cento das BS, respectivamente) e houve 67,9 dos casos com BS e assintomáticos. As amostras testadas destas bactérias prevalentes foram sensíveis à maioria dos antimicrobianos comumente utilizados, com exceçäo da ampiclina. Assim, recomendamos a realizaçäo de urinocultura em diabéticos semelhantes aos deste estudo, que infelizmente, ainda representam a maioria dos que procuram os cuidados médicos, mesmo na ausência de evidência clínica e dos fatores correlacionados à mesma

Atividade in vitro da cefepima em comparação com outras cefalosporinas de amplo espectro contra amostras clínicas de 18 hospitais brasileiros / In vitro activity of cefepime in comparisiom with others cephalosporins of extended-spectrum agaisnt clinical amostra of 18 brazilians hospitals

INTRODUÇÄO: A cefepima é uma cefalosporina de quarta geraçäo lançada recentemente tanto no Brasil quanto nos Estados Unidos. Trabalhos internacionais têm mostrado que esse composto apresenta maior potência tanto contra bacilos gram-negativos quanto cocos gram-positivos aeróbios, quando comparada com as cefalosporinas de terceira geraçäo. OBJETIVO: Avaliar a atividade antimicrobiana da cefepima em comparaçäo com ceftazidima, ceftriaxona, cefotaxima e imipenem em amostras clínicas isoladas em hospitais brasileiros. MATERIAL E MÉTODOS: Foram estudadas 982 amostras clínicas coletadas durante o periódo de dezembro de 1995 a março de 1996. Foi incluída apenas 1 amostra por paciente. As amostras foram testadas através do método de E test seguindo as recomendaçöes do National Commitee for Clinical Laboratory Standards (NCCLS). RESULTADOS: O espectro de ação da cefepima foi superior àquele apresentado pelas outras cefalosporinas de amplo espectro tanto contra bacilos Gram-negativos quanto contra cocos Gram-positivos. A superioridade da cefepima foi mais evidente contra Enterobacter sp. (MIC90, 2µg/ml), Serratia sp. (MIC90, 2µg/ml) e S. aureus sensível à oxacilina (MIC90,3µg/ml). Contra P. aeruginosa, a cefepima (MIC90, 16µg/ml) foi somente um pouco mais ativa que a ceftazidima (MIC90, 32µg/ml) e 8 a 16 vezes mais ativa que a ceftriaxona ou a cefotaxima (MIC90, > 256 µg/ml). DISCUSSÄO: Nossos resultados mostram que bactérias hospitalares, especialmente bacilos Gram-negativos, apresentam altas taxas de resistência às cefalosporinas no Brasil. Porém, uma parte dessas amostras multirresistentes permanecem sensíveis à cefepima

Infecçåo urinária por Escherichia coli: correlaçåo de características clínicas, patogênicas e sorogrupos / Urinary tract infections by Escherichia coli: correlation of virulence, serogroups and clinical characteristics

Estudou-se a uropatogenicidade (pesquisa de adesinas - MSHA, MRHA e hemolisinas) e a sorotipagem (por titulaçåo em tubos) de 248 amostras de E. coli isoladas de pacientes do Hospital das Clínicas da Faculdade de Medicina de Botucatu com quadro clínico de cistite, pielonefrite, bacteriúria assintomática ou indeterminado. Observou-se que: as amostras relacionadas pielonefrite apresentaram hemaglutinaçåo manose resistente (MRHA) em maior proporçåo (54,3 por cento), hemaglutinaçåo manose sensível (MSHA) foi observada em mais de 91 por cento das bactérias de todos os quadros clínicos, enquanto que amostras hemolíticas (53,2 por cento em média) se distribuiram uniformemente pelos mesmos. Os sorogrupos prevalentes foram: O7 (20,8 por cento), O2 (18,5 por cento) e O4 (18,5 por cento) em pielonefrite; O18ac (41,9 por cento) e O7 (41,7 por cento em cistite e O75 (26,9 por cento) em assintomáticos. Todas as amostras O18ac e O4 provenientes de pielonefrite apresentaram MRHA e 82 por cento delas, hemolisinas. Estes dados sugerem que em determinados sorogrupos de E. coli, alguns fatores de virulência coexistem, favorecendo, assim, sua sobrevivência nas céluls uroepiteliais

Caracterizaçäo da sensibilidade bacteriana aos antimicrobianos no Brasil - 1980-1987 / Characterization of the bacterial sensitivity antimicrobial agents in Brazil - 1980-1987

Por meio do antibiograma realizado com 44.583 amostras bacterianas (E.coli - 20.326, Klebsiella sp - 7.444, Proteus mirabilis - 3.286, Pseudomonas sp - 5.315 e S. aureus - 8.212 nos Laboratórios de Referência do Sistema COBA, no período de 1980 a 1987, pode-se caracterizar a sensibilidade e sua evoluçäo a 6 antimicrobianos (sulfametoxazol + trimetoprim, cefalotina, cefoxitina, gentamicina, amicacina e ampicilina) de uso freqüente em nosso meio. Amicacina e cefoxitina apresentaram a maior atividade "in vitro", enquanto os mais elevados índices de resistência foram registrados para Pseudomonas sp e Klebsiella sp. A análise da evoluçäo revelou maior tendência à manutençäo ou queda da resistência em amostras de Proteus mirabilis e à elevaçäo da mesma entre S. aureus. Em relaçäo às drogas, houve nítida elevaçäo da resistência a cefalotina para E. coli; a cefalotina e cefoxitina para Klebsiella sp; a sulfametoxazol +_ trimetoprim, ampicilina, cefoxitina e amicacina para S. aureus; observou-se também diminuiçäo da resistência à gentamicina em relaçäo a todos os germes