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Streptococcus agalactiae is a common agent of clinical and subclinical bovine mastitis and an important cause of human infections, mainly among pregnant women, neonates and nonpregnant adults with underlying diseases. The present study describes the genetic and phenotypic diversity among 392 S. agalactiae human and bovine strains isolated between 1980 and 2006 in Brazil. The most prevalent serotypes were Ia, II, III and V and all the strains were susceptible to penicillin, vancomycin and levofloxacin. Resistance to clindamycin, chloramphenicol, erythromycin, rifampicin and tetracycline was observed. Among the erythromycin resistant strains, mefA/E, ermA and, mainly, ermB gene were detected, and a shift of prevalence from the macrolide resistance phenotype to the macrolide-lincosamide-streptogramin B resistance phenotype over the years was observed. The 23 macrolide-resistant strains showed 19 different pulsed-field gel electrophoresis profiles. Regarding macrolide resistance, a major concern in S. agalactiae epidemiology, the present study describes an increase in erythromycin resistance from the 80s to the 90s followed by a decrease in the 2000-2006 period. Also, the genetic heterogeneity described points out that erythromycin resistance in Brazil is rather due to horizontal gene transmission than to spreading of specific macrolide-resistant clones., (Copyright © 2013 Elsevier Editora Ltda. All rights reserved.)

This study investigated the participation and risk factors of VAP by resistant (ORSA) or sensitive (OSSA) S. aureus to oxacillin and evaluated the implications of adequate or inadequate empirical antimicrobial therapeutics in its evolution in patients interned in a mixing ICU of adults. A patient control-case study with PAVs by ORSA and OSSA was carried out from May 2005 to April 2007 involving 993 patients. VAP was defined based on clinical, radiological, and microbiological (>or= 10(6) CFU/mL count in the tracheal aspirate) criteria. Four hundred and seventy four (47.7%) patients were submitted to mechanical ventilation with 141 (29.7%) VAPs, with S. aureus as the most frequent agent (41.2%). The phenotype ORSA accounted for 47.5% and OSSA for 52.5%, predominant in late-onset VAPs with frequencies of 93.1% and 68.7%, respectively. Age > 60, use of corticoid and previous antibiotic therapy were related (p<0.05) with the development of VAP by ORSA. Mortality rate was higher (p>0.05) in the group with VAP by ORSA (37.9%). S. aureus was the main agent of VAPs, around half by ORSA, associated with age, late-onset VAP development and previous use of antibiotics and corticoids, but with no significant difference in mortality compared with VAP by OSSA.

The objective of this study was to evaluate clinical characteristics, etiology, and resistance to antimicrobial agents, among patients with ventilator-associated pneumonia (VAP). A case study vs. patients control under mechanical ventilation and hospitalized into clinical-surgical adults ICU of HC-UFU was performed from March/2005 to March/2006. Patients under ventilation for over 48 h were included in the study including 84 with diagnosis of VAP, and 191 without VAP (control group). Laboratory diagnosis was carried out through quantitative microbiological evaluation of tracheal aspirate. The identification of pathogens was performed by classical microbiological tests, and the antibiotics sensitivity spectrum was determined through the CLSI technique. VAP incidence rate over 1,000 days of ventilation was 24.59. The mean (+/- SD) duration of mechanical ventilation prior to VAP diagnosis was 23.2 +/- 17.2 days. By multivariate analysis the risk factors predisposing for VAP were: mechanical ventilation time and mechanical ventilation > seven days, tracheostomy and use of > or = three antibiotics. Mortality rate was high (32.1 %) but lower than that of the control group (46.5%). Major pathogens were identified in most of patients (95.2%) and included: Pseudomonas aeruginosa (29%), Staphylococcus aureus (26%), Enterobacter/Klebsiella/Serratia (19%) and Acinetobacter spp. (18%), with expressive frequencies of P. aeruginosa (52%), S. aureus (65.4%) and Enterobacteriaceae (43.7%) resistant to imipenem, oxacillin and 3/4 generation cephalosporins, respectively. In conclusion, our observation showed VAPs caused by multiresistant microorganisms, the prescription of > or = three antibiotics, and mortality with unacceptably high rates. The practice of de-escalation therapy appears to be urgently needed in order to improve the situation.