Prevalence of Vibrio cholerae in Coastal Alternative Supplies of Drinking Water and Association with Bacillus-Like Spore Formers

Abstract

The scarcity of hygienic drinking water is a normal phenomenon in the coastal areas of Bangladesh due to the high salinity of ground water. The inhabitants of this locality, therefore, live on alternative supplies of water including rain-fed pond water, and rainwater with persistent complex microbial interactions therein, often contaminated with life-threatening pathogens. Hence, this study was aimed at analyzing the prevalence of Vibrio cholerae (Vc) in the alternative drinking waters of Mathbaria, a coastal subdistrict neighboring the Bay of Bengal, the efficacy of pond sand filter (PSF) and the co-association among Bacillus-like spore formers (Sf) and Vc. Vc presumably entrapped into the membrane filter was enriched in alkaline peptone water medium and was isolated on selective thiosulfate-citrate-bile salts-sucrose and taurocholate-tellurite-gelatin agar media. They were finally identified by immunochromatographic one step rapid test and serology test. A total of 26% Vc positive samples were obtained out of 100 [ponds—48, household (HH)—29, and PSFs—23] where 13% cases were pathogenic (Vc O1) and 13% were non-pathogenic (Vc non-O1/non-O139). The distribution of Vc as observed was 33, 26, and 13.8% in waters derived from pond surface, PSF, and HH reservoirs, respectively, and for pathogenic type, it was 62.5%, 50%, and nil, respectively. Although none of the samples was identified with pathogenic Vc O139, the statistics represents a significant and augmentative risk of cholera outbreak in the focused area. The antibiotic sensitivity pattern in this study resembled the trend observed during last few years for Vc. The PSF demonstrated its inability to remove Vc from any of the samples and in addition, the filter itself was evidenced to be the source of pathogens and spores in further contamination and transmission. The development of biofilm in the PSF could be hypothesized as the reservoir in contaminating pathogen-free water samples. From the test of homogeneity, the risk levels of alternative water sources were estimated equal regarding Vc. Simultaneously, it was determined statistically that the prevalence of Vc, by no means, is influenced by Bacillus-like Sf be it for pond surface, HH, or PSF derived water.

Recovery of Pasteurization-Resistant Vibrio parahaemolyticus from Seafoods Using a Modified, Two-Step Enrichment

“…Our findings suggest, for the first time, that V. parahaemolyticus could survive food processing and cooking criteria [ 15 ], which could be an overlooked root cause of the persistent vibriosis in the US, and that they could be activated/recovered using the modified, two-step enrichment of combined nourishment (APW, 48 h), heating selection (80 °C, 20 min), and cooling steps. As previously noted, the prevalence of the V. parahaemolyticus variant [ 5 , 21 , 55 ], such as heat-resistant strains of environmental V. parahaemolyticus , could be attributed to specific gene transfers within the bacterial complex/mixture community, that could consist of Vibrio species and heat-resistant symbionts [ 73 ], and induced by global warming [ 74 ]. The results revealing positive KP activity and tlh amplicons suggest the presence of environmental V. parahaemolyticus pathogens [ 19 , 20 ], and that these strains (i.e., VHT1 and VHT2 derived strains, VHT79, VHT80, and VHT81) ( Table 5 and Table 7 ) possess heat-stable hemolysin gene(s), such as tlh , and that it encodes a heat-stress protecting product, possibly suggesting a positive correlation between V. parahaemolyticus heat resistance (i.e., 62 °C, 8 h) and persistent vibriosis cases, as noted by Ueda et al [ 75 ], whose work determined a positive correlation between thermolabile protein expression and thermotolerance in a member of Gram-negative bacteria.…”

Feasibility and Efficacy Study of Spices in Meat Preservation

“…The inocula of the test organisms were prepared by transferring one loop-full of the colony from TSA (Sigma, USA) medium into 9.0 ml of sterile Mueller-Hinton Broth (Difco, Sparks, MD) and incubated at 37°C for 5 to 6 hours. The bacterial cultures were compared with the McFarland turbidity standard (10 8 CFU/ml) prepared by mixing 0.05 ml of 1.175% Barium chloride dihydrate (BaCl2.2H2O), with 9.95 ml of 1% sulfuric acid (H2SO4) in a test tube with constant stirring (16,17).…”

“…The antibacterial activity of ethanol extracts of spices was evaluated following the agar well diffusion method (18). In brief, to prepare bacterial lawn of test pathogens, overnight liquid cultures in MHB medium at desired turbidity of 0.5 M McFarland standard were seeded on Muller Hinton Agar (MHA) plates with sterilized cotton swabs (16,17). The cotton swabs were soaked in the liquid cultures and applied evenly in three directions at an angle of 60°C onto the surface of MHA plates.…”