Coagulase-Negative Staphylococci Isolated from Human Bloodstream Infections Showed Multidrug Resistance Profile.

Coagulase-negative staphylococci (CNS) are important pathogens causing nosocomial infections worldwide with increasing resistance to antimicrobials. The aim of this study was to characterize resistance aspects of CNS isolated from patients with bloodstream infections acquired in hospitals in Belo Horizonte, MG, Brazil. Staphylococcus strains were characterized using repetitive sequence-based polymerase chain reaction (rep-PCR) fingerprinting with (GTG)5 primer. Phenotypic resistance was analyzed using AST-P5085 card (bioMérieuxVitek®). PCR was used to detect mecA, vanA, blaZ, ermA/B/C, aac-aphD, and SCC-mec. For statistical analyses, we used hierarchical cluster, chi-square test (χ2), and correspondence. Several clusters were formed within the same species using (GTG)5 primer, and strains showed resistance to the following antimicrobials: benzylpenicillin (100%); oxacillin (93.1%); gentamicin (36.3%); ciprofloxacin (63.7%); moxifloxacin (32.7%); norfloxacin (81.0%); erythromycin (86.2%); clindamycin (75.8%); linezolid, teicoplanin and vancomycin (1.7%); tigecycline (0%); fusidic acid (10.35%); rifampicin (13.7%); and trimethoprim/sulfamethoxazole (46.5%). Regarding genotypic analyses, 40%, 0%, 78%, 42%, 100%, 24%, and 30% were positive for mecA, vanA, blaZ, ermA, ermB, ermC, and aac-aphD, respectively. Regarding staphylococcal cassette mec (SCCmec) type, 3.4% presented type I; 5.0% type II; 27.1% type III; 20.3% type IIIA; and 32.2% type IIIB. Six clusters were formed and frequency distributions of resistant strains to oxacillin, gentamicin, ciprofloxacin, moxifloxacin, norfloxacin, erythromycin, clindamycin, linezolid, teicoplanin, vancomycin, fusidic acid, rifampicin, and trimethoprim/sulfamethoxazole, and mecA, blaZ, ermC, aac-aphD, and SCCmec type differed (p < 0.001). In conclusion, the strains investigated in this study were multidrug resistant and carried multiple antibiotic resistance genes.

Procalcitonin versus C-reactive protein for guiding antibiotic therapy in sepsis: a randomized trial.

OBJECTIVE: We sought to evaluate whether procalcitonin was superior to C-reactive protein in guiding antibiotic therapy in intensive care patients with sepsis. DESIGN: Randomized open clinical trial. SETTING: Two university hospitals in Brazil. PATIENTS: Patients with severe sepsis or septic shock. INTERVENTIONS: Patients were randomized in two groups: the procalcitonin group and the C-reactive protein group. Antibiotic therapy was discontinued following a protocol based on serum levels of these markers, according to the allocation group. The procalcitonin group was considered superior if the duration of antibiotic therapy was at least 25% shorter than in the C-reactive protein group. For both groups, at least seven full-days of antibiotic therapy were ensured in patients with Sequential Organ Failure Assessment greater than 10 and/or bacteremia at inclusion, and patients with evident resolution of the infectious process had antibiotics stopped after 7 days, despite biomarkers levels. MEASUREMENTS AND MAIN RESULTS: Ninety-four patients were randomized: 49 patients to the procalcitonin group and 45 patients to the C-reactive protein group. The mean age was 59.8 (SD, 16.8) years. The median duration of antibiotic therapy for the first episode of infection was 7.0 (Q1-Q3, 6.0-8.5) days in the procalcitonin group and 6.0 (Q1-Q3, 5.0-7.0) days in the C-reactive protein group (p=0.13), with a hazard ratio of 1.206 (95% CI, 0.774-1.3; p=0.13). Overall, protocol overruling occurred in only 13 (13.8%) patients. Twenty-one patients died in each group (p=0.836). CONCLUSIONS: C-reactive protein was as useful as procalcitonin in reducing antibiotic use in a predominantly medical population of septic patients, causing no apparent harm.

Effects of oxidative stress on the virulence profile of Prevotella intermedia during experimental infection in gnotobiotic mice.

Prevotella intermedia is a component of the indigenous microbiota but is also responsible for anaerobic infections of the gastrointestinal tract and oral cavity. The aim of the present study was to investigate the influence of oxidative stress on the in vivo pathogenicity of P. intermedia. Germ-free mice were challenged intraperitoneally with parental (wt) or oxidative stress adapted (aero) strains. Bacterial virulence was evaluated by histopathology, hyperaemia and blood analysis [C-reactive protein (CRP), serum albumin and white blood cells (WBCs)], 3 and 10 days after challenge. CRP levels and WBC count were higher in animals challenged with the aero strain, and the albumin level was lower in this group, only 10 days after infection (P<0.05). Body weight gain was significantly reduced whereas hyperaemia and ratios of spleen/organ weight were increased in animals challenged with the aero strain (P<0.05). The liver of animals challenged with the aero strain showed hyperaemia, vasodilatation as well as an increase in the number of inflammatory cells and liver/organ weight ratio (P<0.05). Similar, but more discrete, alterations were observed in the small intestine of animals challenged with the aero strain. Studies on stress responses of this putative pathogen may help to better understand the aggressive potential and virulence markers of anaerobic bacteria.