Usefulness of catheter tip culture in the diagnosis of neonatal infections

Objective: To determine the number of colony-forming units (CFU) that best correlates with catheter-related infections (CRI) in newborns.Methods: This was a prospective study of semiquantitative cultures of catheter tips obtained from newborns in the neonatal unit at Faculdade de Medicina de Botucatu, state of São Paulo, Brazil. The microorganisms isolated from catheter and peripheral blood cultures were identified and submitted to a drug susceptibility test. The optimal cutoff point was determined by the receiver operating characteristic (ROC) curve.Results: A total of 85 catheters obtained from 63 newborns were studied. Staphylococcus epidermidis was the predominant species in the catheters (75%). Eight of 11 (72.7%) CRI episodes were associated with coagulase-negative staphylococci, six of which were of the S. epidermidis type. ROC curve analysis indicated that the optimal cutoff point for the diagnosis of CRI was 122 CFU.Conclusions: The cutoff point of 122 CFU correlated best with the diagnosis of CRI in newborns.

Aspectos citológicos e microbiológicos do leite em propriedades no sistema orgânico de produção

A produção de leite no sistema orgânico tem despertado o interesse dos produtores rurais, pelo aumento de consumo de produtos naturais. Estudaram-se os aspectos citológicos e microbiológicos do leite no sistema orgânico de produção em quatro propriedades no município de Botucatu, SP, utilizando métodos como CMT, exame microbiológico das amostras positivas, contagem de células somáticas (CCS/mL de leite) e Contagem de Unidades Formadoras de Colônias (UFC de microrganismos mesófilos/mL de leite) em amostras individuais de leite em animais com pelo menos um teto positivo ao CMT. Foi também realizado a CCS/mL de leite e UFC/mL de leite, e exame microbiológico de amostras de leite do conjunto (tanque) de cada propriedade. Das 150 glândulas mamárias examinadas, 66 (44,00%) amostras foram positivas ao CMT, com isolamento de Corynebacterium bovis em 37,90%, Staphylococcus aureus (18,20%), S. epidermidis (15,20%), Streptococcus uberis (3,00%) e S. dysgalactiae (3,00%), e isolamento de mais de um agente bacteriano em 7,60% das amostras. Os valores de CCS/mL das amostras do leite de conjunto estiveram dentro dos limites de normalidade em três das quatro propriedades (< 400x10³), por outro lado considerando a UFC/mL em três das quatro propriedades observou-se altos índices (8,5x10(5); 1,5x10(6); 4,1x10(5)). Obteve-se o isolamento de microrganismos ambientais, como Escherichia coli e Pseudomonas aeruginosa, sugerindo a contaminação do leite durante ou após a ordenha, o que reforça a importância de atividades de educação sanitária para obtenção higiênica do leite.

Inhibition of Sodium Hypochlorite Antimicrobial Activity in the Presence of Bovine Serum Albumin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Predictive factors of outcome following staphylococcal peritonitis in continuous ambulatory peritoneal dialysis

Background and aims: Staphylococcus epidermidis and other coagulase-negative staphylococci (CoNS) are the most common agents of continuous ambulatory peritoneal dialysis (CAPD) peritonitis. Episodes caused by Staphylococcus aureus evolve with a high method failure rate while CoNS peritonitis is generally benign. The purpose of this study was to compare episodes of peritonitis caused by CoNS species and S. aureus to evaluate the microbiological and host factors that affect outcome. Material and methods: Microbiological and clinical data were retrospectively studied from 86 new episodes of peritonitis caused by staphylococci species between January 1996 and December 2000 in a university dialysis center. The influence of microbiological and host factors (age, sex, diabetes, use of vancomycin, exchange system and treatment time on CAPD) was analyzed by logistic regression model. The clinical outcome was classified into two results (resolution and non-resolution). Results: the odds of peritonitis resolution were not influenced by host factors. Oxacillin susceptibility was present in 30 of 35 S. aureus lineages and 22 of 51 CoNS (p = 0.001). There were 32 of 52 (61.5%) episodes caused by oxacillin-susceptible and 20 of 34 (58.8%) by oxacillin-resistant lineages resolved (p = 0.9713). of the 35 cases caused by S. aureus, 17 (48.6%) resolved and among 51 CoNS episodes 40 (78.4%) resolved. Resolution odds were 7.1 times higher for S. epidermidis than S. aureus (p = 0.0278), while other CoNS had 7.6 times higher odds resolution than S. epidermidis cases (p = 0.052). Episodes caused by S. haemolyticus had similar resolution odds to S. epidermidis (p = 0.859). Conclusions: S. aureus etiology is an independent factor associated with peritonitis non-resolution in CAPD, while S. epidermidis and S. haemolyticus have a lower resolution rate than other CoNS. Possibly the aggressive nature of these agents, particularly S. aureus, can be explained by their recognized pathogenic factors, more than antibiotic resistance.

Detection of enterotoxins genes in coagulase-negative staphylococci isolated from foods

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of toxigenic capacity by reverse transcription polymerase chain reaction in coagulase-negative staphylococci and Staphylococcus aureus isolated from newborns in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identification and antimicrobial susceptibility of Staphylococcus from home-treated peritoneal dialysis patients

Staphylococcus aureus is the main agent of infections during peritoneal dialysis (PD). The presence of S. aureus in the nasal cavity has been extensively studied and suggested as a risk factor of dialysis-related infections, whereas coagulase-negative Staphylococcus (CNS) species are frequently considered part of the normal human microbiota. The aim of this study was to identify Staphylococcus in the nasal cavity, pericatheter skin and peritoneal effluent from PD patients, as well as to evaluate the antimicrobial activity evolution in vitro. Thirty-two chronic PD patients were observed during 12 months and had nasal and pericatheter skin samples collected for culture. When peritonitis was detected, samples were also collected from the peritoneal effluent for culture. The activity of several antimicrobial drugs (penicillin G, oxacillin, cephalothin, ofloxacin, netilmicin and vancomycin) against different Staphylococcus species was measured by using the agar drug diffusion assay (Kirby-Bauer method). Staphylococcus was separated into S. aureus, S. epidermidis and other CNS species in order to determine the in vitro resistance level. S. epidermidis resistance to oxacillin progressively increased during the study period (p < 0.05). Resistance to ofloxacin was inexpressive, whereas resistance to netilmicin and vancomycin was not detected. of the oxacillin-resistant species (n = 74), 83% were S. epidermidis, 13% other CNS and 4% S. aureus (p < 0.05). Regarding multidrug resistant strains (n = 45), 82% were S. epidermidis, 13% other CNS, and 5% S. aureus (p < 0.05). This study shows the relevance of resistance to oxacillin and CNS multi-drug resistance, particularly concerning S. epidermidis, in PD patients.

Molecular detection of enterotoxins E, G, H and I in Staphylococcus aureus and coagulase-negative staphylococci isolated from clinical samples of newborns in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Polymerase Chain Reaction Detection of Enterotoxins Genes in Coagulase-Negative Staphylococci Isolated from Brazilian Minas Cheese

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of photodynamic therapy on clinical isolates of Staphylococcus spp

Staphylococcus spp. are opportunistic microorganisms known for their capacity to develop resistance against antimicrobial agents. The objective of this study was to evaluate the effect of photodynamic therapy (PDT) on 20 Staphylococcus strains isolated from the human oral cavity, including S. aureus, S. schleiferi, S. epidermidis, S. capitis, S. haemolyticus, and S. lentus. A suspension of each Staphylococcus strain (10(6) cells/mL) was submitted to PDT using methylene blue and a low power laser. The isolated effects of methylene blue, laser treatment and ciprofloxacin were also evaluated. After the experimental treatments, 0.1 mL aliquots of the suspensions were seeded onto BHI agar for determination of the number of colony-forming units (CFU/mL). The results were analyzed by analysis of variance and Tukey's test (p < 0.05). The mean reduction in bacterial counts of the strains submitted to PDT ranged from 4.89 to 6.83 CFU (log10)/mL, with the observation of a decreasing susceptibility to treatment of S. schleiferi, S. haemolyticus, S. epidermidis, S. capitis, S. aureus, and S. lentus. The results showed that PDT was effective in reducing the number of viable cells of all clinical Staphylococcus isolates studied.

Oral microbial colonization in patients with systemic lupus erythematous: correlation with treatment and disease activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of TNF-alpha blockers on the oral prevalence of opportunistic microorganisms in ankylosing spondylitis patients

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Staphylococcus spp., Enterobacteriaceae and Pseudomonadaceae oral isolates from Brazilian HIV-positive patients. Correlation with CD4 cell counts and viral load

The aim was to evaluate the presence of Staphylococcus spp., Enterobacteriaceae and Pseudomonadaceae in the oral cavities of HIV-positive patients. Forty-five individuals diagnosed as HIV-positive by ELISA and Western-blot, and under anti-retroviral therapy for at least 1 year, were included in the study. The control group constituted 45 systemically healthy individuals matched to the HIV patients to gender, age and oral conditions. Oral rinses were collected and isolates were identified by API system. Counts of microorganisms from HIV and control groups were compared statistically by a Mann-Whitney test (alpha = 5%). The percentages of individuals positive for staphylococci were similar between the groups (p = 0.764), whereas for Gram-negative rods, a higher percentage was observed amongst HIV-positive (p = 0.001).There was no difference in Staphylococcus counts between HIV and control groups (p = 0.1008). Counts were lower in the oral cavities of patients with low viral load (p = 0.021), and no difference was observed in relation to CD4 counts (p = 0.929). Staphylococcus aureus was the most frequently isolated species in HIV group, and Staphylococcus epidermidis was the prevalent species in the control group. Significantly higher numbers of enteric bacteria and pseudomonas were detected in the oral cavities of the HIV group than in the control (p = 0.0001). Enterobacter cloacae was the most frequently isolated species in both groups. Counts of enteric bacteria and pseudomonas were significantly lower in patients with low CD4 counts (p = 0.011); however, there was no difference relating to viral load. It may be concluded that HIV group showed greater species diversity and a higher prevalence of Enterobacteriaceae/Pseudomonadaceae. (C) 2011 Elsevier Ltd. All rights reserved.

Staphylococcus spp. in the oral cavity and periodontal pockets of chronic periodontitis patients

Staphylococcus spp. não são usualmente isolados a partir da cavidade bucal. Quando presentes, são considerados pertencentes à microbiota transitória. Indivíduos que apresentam doença periodontal representam possíveis reservatórios dessas bactérias oportunistas na cavidade bucal. O uso de antibióticos para o tratamento da doença periodontal ou outras infecções pode predispor o aumento do número de Staphylococcus spp. na boca, pois estes adquirem facilmente resistência aos antibióticos, podendo resultar em superinfecção. O objetivo deste estudo foi verificar a presença de Staphylococcus spp. na cavidade bucal e nas bolsas periodontais de pacientes com periodontite crônica; identificar as cepas isoladas; verificar a relação entre a presença de Staphylococcus spp. na cavidade bucal e presença de bolsa periodontal. Participaram deste estudo 88 pacientes, entre 25 e 60 anos de idade e apresentando periodontite crônica, com pelo menos dois sítios com profundidade de sondagem maior ou igual a 5mm. Após anamnese e exame clínico periodontal foram feitas coletas de material da bolsa periodontal com cones de papel e da cavidade bucal por meio de bochechos. do total de pacientes 37,50% apresentaram Staphylococcus spp. na bolsa periodontal e 61,36% na cavidade bucal, sendo que 27,27% apresentaram a bactéria nos 2 sítios. S. epidermidis foi a espécie mais prevalente para bolsa periodontal (15,9%) e cavidade bucal (27,27%). Não houve diferença estatística significante quanto à presença desses microrganismos entre as faixas etárias e aumento da profundidade de sondagem. A presença de bactérias oportunistas na cavidade bucal pode representar dificuldades para a manutenção do tratamento periodontal.

Estudo da produção de beta -lactamase e sensibilidade às drogas em linhagens de estafilococos coagulase-negativos isolados de recém-nascidos

Os estafilococos coagulase-negativos (ECN), embora reconhecidos como saprófitas por muito tempo, têm emergido como agentes etiológicos de uma série de infecções, sendo atualmente os principais responsáveis por sepse em UTI neonatal. Tendo em vista estas características, este estudo objetivou a identificação de estafilococos coagulase-negativos isolados de processos infecciosos em recém-nascidos, bem como a determinação da produção de beta-lactamase e sensibilidade às drogas pelas linhagens isoladas. O Staphylococcus epidermidis foi a espécie mais freqüentemente isolada (77,8%). O estudo da produção de beta-lactamase revelou esta característica na maioria das linhagens de ECN isoladas (71,8%). As linhagens de ECN mostraram, ainda, resistência múltipla aos antibióticos utilizados, com 63,2% dos isolados apresentando resistência a cinco ou mais drogas. A elevada transmissibilidade de plasmídios entre estas linhagens e o uso abusivo de drogas antimicrobianas têm-se constituído em importantes fatores na seleção de amostras multirresistentes e na transferência de genes de resistência.