Group B streptococcal bacteriuria during pregnancy as a risk factor for maternal intrapartum colonization: a prospective cohort study.

PURPOSE: Current evidence is inconclusive regarding the intrapartum administration of chemoprophylaxis, merely based on the presence of group B streptococcal (GBS) bacteriuria of any colony count, in the prevention of early-onset neonatal GBS infection. The aim of this study was to assess whether GBS bacteriuria is a risk factor for intrapartum colonization (IPC) regardless of urinary concentration or the results of late third-trimester rectovaginal screening cultures (RVSCs). METHODOLOGY: Six hundred and eight pregnant women, with urine specimens cultured between May 2011 and May 2013, were enrolled in this prospective cohort study. RVSCs were available for 582 women and intrapartum rectovaginal cultures for 246. RESULTS: The prevalence of GBS bacteriuria and positive RVSCs was 10.8 and 16.5 %, respectively. The frequency of IPC was 15.9 % (39/246). Sensitivity, specificity, positive and negative predictive values of urine culture and of RVSC in predicting GBS IPC were 41, 94.7, 59.3 and 89.5 %, and 76.9, 95.4, 76.9 and 95.4 %, respectively. GBS bacteriuria was significantly associated with IPC, overall [relative risk (RR) 5.6] and in women with negative RVSC (RR 8.5), with bacteriuria <104 c.f.u. ml-1 (RR 5.9) or when both circumstances coexisted (RR 8.9). The urinary colony count was <104 c.f.u. ml-1 in 13 of the 16 women with GBS bacteriuria and IPC. CONCLUSION: GBS bacteriuria is a risk factor for IPC, irrespective of urinary GBS concentration or of colonization status at late gestation. Therefore, microbiology laboratories should search, and report, GBS of any colony count in urine from pregnant women, and not only in the presence of ≥104 c.f.u. ml-1 as the 2010 CDC guidelines recommend.

ß-Lactamases, transferable quinolone resistance determinants, and class 1 integron-mediated antimicrobial resistance in human clinical Salmonella enterica isolates of non-Typhimurium serotypes.

This work investigates the occurrence and features of class 1 integrons and the presence of transferable quinolone resistance determinants (TQRD) among 382 clinical Salmonella enterica isolates of non-Typhimurium serotypes as well as the ß-lactamases produced by amoxicillin-resistant isolates. These isolates were recovered in 2001 and from 2004 to 2009 from patients from the health region of Terres de l'Ebre (Catalonia, Spain) and comprised 41 different serotypes, mostly of serovar Enteritidis (n=272), being 16.5% multidrug-resistant (MDR). Among the 93 amoxicillin-resistant isolates, 84 produced TEM-1,4 produced an extended-spectrum ß-lactamase (CTX-M-9 in one S. Grumpensis and in one S. Virchow, CTX-M-15 in S. Kapemba, and SHV-12 in S. Enteritidis), one produced DHA-1 (S. Newport), and 4 did not present any of the investigated ß-lactamases. TQRD were found in 2 isolates (qnrA1 in CTX-M-9-producing S. Grumpensis and qnrB4 in DHA-1-producing S. Newport). Overall, 35 isolates (9.2% of all isolates and 54% of MDR isolates) belonging to 15 different serotypes carried class 1 integrons that were transferred by conjugation in 17 isolates. Eleven distinct cassette arrangements were identified, with dfrA1-aadA1, dfrA17-aadA5, and dfrA12-orfF-aadA2 being the most prevalent and widely distributed ones. Atypical sul3-associated integrons were detected in 5 isolates of serotypes Rissen and Enteritidis. Moreover, the presence of integrons in the serotypes Kapemba, Mikawasima, and [9,12:Iv:i:-], of the estX-psp (linked to sul3) and aadA13-sat cassette arrangements in S. enterica, of extended-spectrum ß-lactamases in S. Kapemba and S. Grumpensis, and of TQRD in S. Grumpensis is reported here for the first time.