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.

Phenotype characterization of Staphylococcus species strains isolated from buffalo (Bubalus bubalis) milk

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

Dimetilsulfóxido - DMSO no teste de sensibilidade microbiana in vitro em cepas de Rhodococcus equi isoladas de afecções pulmonares em potros

Comparou-se a sensibilidade microbiana in vitro de isolados de Rhodococcus equi pelo teste padrão de difusão com discos, com o modificado, pela adição de 5% de dimetilsulfóxido-DMSO. Observou-se aumento da sensibilidade do R. equi no teste com DMSO, frente a aminoglicosídeos (canamicina, amicacina, estreptomicina) e ao cloranfenicol, enquanto para a eritromicina e derivados ß-lactâmicos (penicilina G, cefalosporinas, amoxicilina, oxacilina), constatou-se redução da sensibilidade do agente.

Sensitivity of ant (Cephalotes) colonies and individuals to antibiotics implies feeding symbiosis with gut microorganisms

Ants in the tribe Cephalotini are exceptional in that they maintain microorganisms in their digestive tract. To understand what these microorganisms mean to the ants, we observed the feeding habits of Cephalotes pusillus and Cephalotes atratus, finding that in nature they feed on extrafloral nectars, homopteran secretions, and bird droppings. Feeding the antibiotic kanamycin to colonies of C. pusillus in the laboratory kills them. Ants desiccate or starve rather than feed on liquids to which the antibiotics gentamycin and netilmycin have been added, but feed and survive on liquids containing nystatin, penicillin, and ampicillin. We identified over 10 microorganisms from the intestine of C. pusillus with different antibiotic-resistance patterns. The bacteria are from the genera Corynebacterium, Brevibacterium, Sphingobacterium, Ochrobactrum, Myroides, Brevundimonas, Alcaligenes, Stenotrophomonas, Moraxella, and Pseudomonas. We hypothesize that the microorganisms provide nutrients to the ants by synthesizing amino acids from carbohydrates and nitrates. We do not know whether the ants collect the bacteria from the environment, but they transmit them to their young. They culture them in their digestive tract, eventually feeding on them.

Staphylococcus aureus: Resistance patterns to antimicrobials and Penicillinase among strains isolated from apparently healthy lactating cows

Ninety-two strains of Staphylococcus aureus isolated from the nasal fossa and udder skin of apparently healthy lactating cows were analyzed for resistance to antibiotics and production of penicillinase.The results showed a greater frequency of resistance patterns to penicillin and ampicillin.All strains were sensitive to oxacyllin and gentamicin.The most frequent Barber and Burston model was SSSS (60.90%), followed by RSSS (18.50%).With respect to the production of penicillinase although the Lucas method indicated a larger number of positive samples, we suggest the use of the Haight and Finland method due to a greater consistency of data obtained with it.

SALMONELLA IN POULTRY FEEDS IN BRAZIL

This experiment was undertaken to determine the possible presence of Salmonella in poultry diets. A total of two hundred samples of ration from 4 commercial poultry feed industries were examined. The results revealed the presence of salmonellae in 10% of the samples studied and 14 serotypes were identified. The procedure for Salmonella isolation included the pre-enrichment step and the strains were submitted to antimicrobial tests. The 29 strains were resistant to the followings antimicrobial agents (% of resistance in parenthesis): Erythromycin (100%), sulphonamides (100%), colistin (100%), streptomycin (100%), bacitracin (100%), penicillin (100%), tetracycline (92,9%), cephalothin (75%), carbenicillin (62,5%), ampicillin (46,5%), kanamycin (46,5%), nitrofurantoin (39,3%), neomycin (25%), amikacin (21,4%), sulphazotrin (21,4%), nalidix acid (18,8%), chloramphenycol (17,9%), linco-spectin (17,9%), gentamicin (17,9%), and cefoxitin (6,3%).

Predictors of incorrectness in antimicrobial prescription in the Bauru State Hospital (Bauru city, São Paulo State, Brazil)

The inappropriate use of antimicrobials in hospitals presents a negative impact on patient outcome and is associated with the emergence and spread of multidrug-resistant microorganisms. Antimicrobial stewardship programs (ASPs) have been instituted in order to improve the quality of prescriptions in hospitals. In this setting, the identification of patterns of inappropriate antimicrobial prescription is a valuable tool that allows ASPs to identify priorities for directing educative/restrictive policies. With this purpose, a study was conducted in the Bauru State Hospital, a teaching hospital with 285 beds affiliated to the Botucatu Medical School, São Paulo State University. The hospital maintains an active ASP since it was opened, in 2002. We selected 25% of the requests for parenteral antimicrobials (RPAs) from 2005 for analysis. Prescriptions for prophylactic purposes were excluded. All other RPAs were classified according to a modified Kunin and Jones categories. Univariate and multivariable analyses were performed to identify predictors of general inappropriateness and of specific prescription errors. Prescriptions classified as "appropriate'' or "probably appropriate" were selected as controls in all stages of the study. Among 963 RPAs included in our study, 34.6% were inappropriate. General predictors of inappropriateness were: prescription on weekends/holidays (OR = 1.67, 95% CI = 1.20-2.28, p = 0.002), patient from intensive care unit (OR = 1.57, 95% CI = 1.11-2.23, p = 0.01), peritoneal (OR = 2.15, 95% CI = 1.27-3.65, p = 0.004) or urinary tract infection (OR = 1.89, 95% CI = 1.25-2.87, p = 0.002), combined therapy with two or more antimicrobials (OR = 1.72, 95% CI = 1.15-2.57, p = 0.008) and prescriptions including penicillin (OR = 2.12, 95% CI = 1.39-3.25, p = 0.001) or first-generation cephalosporins (OR = 1.74, 95% CI = 1.01-3.00, p = 0.048). Previous consultation with an infectious diseases (ID) specialist had a protective effect against inappropriate prescription (OR = 0.34, 95% CI = 0.24-0.50, p < 0.001). Factors independently associated with specific prescription errors varied. However, consultation with an ID specialist was protective against both unnecessary antimicrobial use (OR = 0.04, 95% CI = 0.01-0.26, p = 0.001) and requests for agents with insufficient spectrum (OR = 0.14, 95% CI = 0.03-0.30, p = 0.01). In conclusion, the analysis of factors predictive of inappropriateness in antimicrobial prescription allowed us to identify issues requiring intervention. Also, it provided a positive feedback of the ASP efficacy, demonstrating the importance of previous consultation with an ID specialist to assure the quality of antimicrobial prescriptions.

Ocorrência de mastite bovina causada por Staphylococcus sp., Streptococcus sp. E Candida sp. em uma propriedade rural no município de Indianópolis – Minas Gerais

The objective of this study was to evaluate the occurrence of bovine mastitis by Staphylococcus sp., Streptococcus sp. and Candida sp. in a rural area of Indianopolis, Minas Gerais. It was realized the California Mastitis Test (CMT) in six collect, a total 671 of milk sample positive. Then the microbiological examination was performed, where the results revealed the presence of 137 milk samples with microbial multiplication. These, showed the presence of Staphylococcus aureus (45.2% of strains), other coagulase negative Staphylococcus (10.2%), Staphylococcus epidermidis (9.4%), Staphylococcus simulans (5.8%), other coagulase negative (15.3%), Streptococcus agalactiae (7.2%), other Streptococcus sp. (5.1%) and yeasts (1.4%). It was found that 100% of Staphylococcus were susceptible to rifampicin, gentamicin and ciprofloxacin; but, resistant to penicillin, tetracycline, and oxacillin. Regarding antimicrobial susceptibility Streptococcus, were employed, except to clindamycin, erythromycin and tetracycline. We conclude that there is a great necessity of proper hygiene practices and taking prophylactic measures taken in order to reduce the infection of animals caused by infectious microorganisms and resistance.

Minimum inhibitory concentrations of Staphylococcus aureus recovered from clinical and subclinical cases of bovine mastitis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

EFEITO DE SURFACTANTES NA ESTABILIDADE DE COMPOSTOS DE USO TERAPEUTICO

A critical revision of literature as regards to the drug stability in the presence of surfactants were realized. The functional groups envolved in the drug decomposition were used to the development of the discussion. The analysis indicated that the detergent effect can be used to control the rates and mechanisms of drug decomposition and to obtain specific information about the drug reactivity in the environment of pharmacological action.