Description of 'Candidatus Berkiella aquae' and 'Candidatus Berkiella cookevillensis', two intranuclear bacteria of freshwater amoebae.

Two novel bacteria of the phylum Proteobacteria were isolated during searches for amoeba-resistant micro-organisms in natural and constructed water systems. Strain HT99 was isolated from amoebae found in the biofilm of an outdoor hot tub in Cookeville, Tennessee, USA, and strain CC99 was isolated from amoebae in the biofilm of a cooling tower in the same city. Both bacteria were Gram-stain-negative cocci to coccobacilli, unculturable on conventional laboratory media, and were found to be intranuclear when maintained in Acanthamoeba polyphaga. The genomes of both isolates were completely sequenced. The genome of CC99 was found to be 3.0 Mbp with a 37.9 mol% DNA G+C content, while the genome of HT99 was 3.6 Mbp with a 39.5 mol% DNA G+C content. The 16S rRNA gene sequences of the two isolates were 94 % similar to each other. Phylogenetic comparisons of the 16S rRNA, mip and rpoB genes, the DNA G+C content and the fatty acid composition demonstrated that both bacteria are members of the order Legionellales, and are most closely related to Coxiella burnetii. The phenotypic and genetic evidence supports the proposal of novel taxa to accommodate these strains; however, because strains HT99 and CC99 cannot be cultured outside of the amoeba host, the respective names 'Candidatus Berkiella aquae' and 'Candidatus Berkiella cookevillensis' are proposed.

Vaginal douching among Latina immigrants.

Little is known about vaginal douching among Latina immigrants in the U.S. Understanding factors associated with douching is important due to the negative reproductive outcomes associated with this practice. This study examined demographic and behavioral factors associated with vaginal douching among Latina immigrants. A cross-sectional anonymous survey was administered among a convenience sample of 206 Latina immigrants aged 19-44 years (mean = 28 years) living in the U.S. at least 6 months (mean = 4 years). Demographic and behavioral characteristics, history of regular douching (at least once a month for 6 months), and current regular douching (at least once a month for the last 6 months) were assessed. Adjusted odds ratios (adj. OR) were estimated using multiple logistic regression. Overall, 25% (n = 50) of women reported ever douching regularly and 15% (n = 31) reported current regular douching. Ever douching regularly was significantly associated with a woman's number of lifetime sex partners (adj. OR = 1.6 per additional partner over one, 95% CI: 1.1-2.5), hormonal contraceptive use (adj. OR = 0.3, 95% CI: 0.1-0.9), and healthcare seeking behavior (adj. OR = 2.3, 95% CI: 1.1-5.2). Regular vaginal douching is a common practice among Latina immigrants. Factors associated with douching in this population vary from those in other U.S. populations and, therefore, it needs to be addressed in a culturally appropriate manner.

Interactions between food-borne pathogens and protozoa isolated from lettuce and spinach.

The survival of Salmonella enterica was recently shown to increase when the bacteria were sequestered in expelled food vacuoles (vesicles) of Tetrahymena. Because fresh produce is increasingly linked to outbreaks of enteric illness, the present investigation aimed to determine the prevalence of protozoa on spinach and lettuce and to examine their interactions with S. enterica, Escherichia coli O157:H7, and Listeria monocytogenes. Glaucoma sp., Colpoda steinii, and Acanthamoeba palestinensis were cultured from store-bought spinach and lettuce and used in our study. A strain of Tetrahymena pyriformis previously isolated from spinach and a soil-borne Tetrahymena sp. were also used. Washed protozoa were allowed to graze on green fluorescent protein- or red fluorescent protein-labeled enteric pathogens. Significant differences in interactions among the various protist-enteric pathogen combinations were observed. Vesicles were produced by Glaucoma with all of the bacterial strains, although L. monocytogenes resulted in the smallest number per ciliate. Vesicle production was observed also during grazing of Tetrahymena on E. coli O157:H7 and S. enterica but not during grazing on L. monocytogenes, in vitro and on leaves. All vesicles contained intact fluorescing bacteria. In contrast, C. steinii and the amoeba did not produce vesicles from any of the enteric pathogens, nor were pathogens trapped within their cysts. Studies of the fate of E. coli O157:H7 in expelled vesicles revealed that by 4 h after addition of spinach extract, the bacteria multiplied and escaped the vesicles. The presence of protozoa on leafy vegetables and their sequestration of enteric bacteria in vesicles indicate that they may play an important role in the ecology of human pathogens on produce.