Association of sexually-transmitted infection and African-American race with Streptococcus agalactiae colonization in pregnancy.

BACKGROUND: Group B Streptococcus (GBS) remains a significant cause of neonatal infection, but the maternal risk factors for GBS colonization remain poorly defined. We hypothesized that there may be an association between antibiotic exposure during pregnancy and GBS colonization and/or the presence of inducible clindamycin resistance (iCLI-R) in GBS isolates from GBS-colonized pregnant women. METHODS: A retrospective cohort study was performed at Louisiana State University Health Sciences Center - Shreveport including demographic and clinical data from 1513 pregnant women who were screened for GBS between July 1, 2009 and December 31, 2010. RESULTS: Among 526 (34.8%) women who screened positive for GBS, 124 (23.6%) carried GBS strains with iCLI-R (GBS-iCLI-R). While antibiotic exposure, race, sexually-transmitted infection (STI) in pregnancy, GBS colonization in prior pregnancy and BMI were identified as risk factors for GBS colonization in univariate analyses, the only independent risk factors for GBS colonization were African-American race (AOR = 2.142; 95% CI = 2.092-3.861) and STI during pregnancy (AOR = 1.309; 95% CI = 1.035-1.653). Independent risk factors for GBS-iCLI-R among women colonized with GBS were non-African-American race (AOR = 2.13; 95% CI = 1.20-3.78) and younger age (AOR = 0.94; 95% CI = 0.91-0.98). Among GBS-colonized women with an STI in the current pregnancy, the only independent risk factor for iCLI-R was Chlamydia trachomatis infection (AOR = 4.31; 95% CI = 1.78-10.41). CONCLUSIONS: This study identified novel associations for GBS colonization and colonization with GBS-iCLI-R. Prospective studies will improve our understanding of the epidemiology of GBS colonization during pregnancy and the role of antibiotic exposure in alterations of the maternal microbiome.

Public health considerations associated with molluscan aquaculture systems: Human viruses.

The documentation of several recent outbreaks of human virus diseases associated with the consumption of shellfish has reiterated the threat posed by these agents to the shellfish industry. This article reviews pertinent outbreaks, identifies principal viral agents involved, and delineates systems which may be at greatest risk. The results of two recent laboratory studies which sought to define environmental factors that contribute to virus accumulation by shellfish are also discussed. First, the accumulation of environmentally significant levels of feces-associated and monodispersed poliovirus by oysters (Crassostrea virginica) and clams (Mercenaria mercenaria) was investigated. The results of this study suggested that virus accumulation by mollusks may not be significant when water column concentrations are below ⋍0.01 plaque-forming units (PFU) per milliliter. The second study focused on the relative contributions of undisturbed sediments versus those in the water column in the accumulation of viruses by epifaunal and infaunal shellfish (C. virginica and M. mercenaria). Viruses were found to be most efficiently accumulated when suspended in the water column.

Isolation of Naturally Occurring Enteroviruses from a Variety of Shellfish Species Residing in Long Island and New Jersey Marine Embayments.

Shellfish ( Crassostrea virginica and Mercenaria mercenaria ) and shellfish-raising waters from a variety of Long Island and New Jersey marine embayments were examined for the presence of human enteroviruses. Little difference in virological quality was noted between areas designated as being open or closed to shellfishing. Viral isolations could not be correlated with coliform counts from identical samples, indicating the need to re-evaluate the use of bacterial standards as indices of the overall sanitary quality of water and shellfish.

Modified Procedure for Extraction of Poliovirus from Naturally-Infected Oysters Using Cat-Floc and Beef Extract.

Methods for recovery of poliovirus type 1 (LSc2ab) from naturally-infected oysters ( Crassostrea gigas ) were examined. Extraction procedures analyzed included glycine-saline and polyelectrolyte (Cat-Floc) methods followed by concentration using modifications of an acid precipitation technique, Direct viral assay of shellfish homogenates, when compared to virus recovery following extraction, indicated that substantially fewer viruses were detected in initial homogenates. These data appeared to support the contention that input values based on homogenate assay were inappropriate in determining recovery efficiencies with naturally-infected shellfish. Since absolute efficiencies could not be determined, relative efficiencies using samples from pooled homogenates were used to determine the recovery efficiencies of various extraction procedures. Cat-Floc extraction followed by a beef extract-modified acid precipitation technique resulted in higher virus recoveries than a glycine-saline extraction procedure.