Molecular Detection and Distribution of Six Medically Important Vibrio spp. in Selected Freshwater and Brackish Water Resources in Eastern Cape Province, South Africa

Abstract

Water resources contaminated with pathogenic Vibrio species are usually a source of devastating infection outbreaks that have been a public health concern in both developed and developing countries over the decades. The present study assessed the prevalence of six medically significant Vibrio species in some water resources in Eastern Cape Province, South Africa for 12 months. We detected vibrios in all the 194 water samples analyzed using polymerase chain reaction (PCR). The prevalence of Vibrio cholerae, Vibrio mimicus, Vibrio fluvialis, Vibrio vulnificus, Vibrio alginolyticus, and Vibrio parahaemolyticus in freshwater samples was 34, 19, 9, 2, 3, and 2%, and that in brackish water samples was 44, 28, 10, 7, 46, and 51%, respectively. The population of the presumptive Vibrio spp. isolated from freshwater (628) and brackish water (342) samples that were confirmed by PCR was 79% (497/628) and 85% (291/342), respectively. Twenty-two percent of the PCR-confirmed Vibrio isolates from freshwater (n = 497) samples and 41% of the PCR-confirmed Vibrio isolates from brackish water samples (n = 291) fall among the Vibrio species of interest. The incidences of V. cholerae, V. mimicus, V. fluvialis, V. vulnificus, V. alginolyticus, and V. parahaemolyticus amidst these Vibrio spp. of interest that were recovered from freshwater samples were 75, 14, 4, 6, 1, and 1%, whereas those from brackish water samples were 24, 7, 3, 3, 47, and 18%, respectively. Our observation during the study suggests pollution as the reason for the unusual isolation of medically important vibrios in winter. Correlation analysis revealed that temperature drives the frequency of isolation, whereas salinity drives the composition of the targeted Vibrio species at our sampling sites. The finding of the study is of public health importance going by the usefulness of the water resources investigated. Although controlling and preventing most of the factors that contribute to the prevalence of medically important bacteria, such as Vibrio species, at the sampling points might be difficult, regular monitoring for creating health risk awareness will go a long way to prevent possible Vibrio-related infection outbreaks at the sampling sites and their immediate environment.

An Assay Combining Droplet Digital PCR With Propidium Monoazide Treatment for the Accurate Detection of Live Cells of Vibrio vulnificus in Plasma Samples

“…Meanwhile, the atypical clinical signs of V. vulnificus infection with increasingly unclear factors of exposure risk have caused difficulties in its early diagnosis and treatment (Liang et al, 2021). With the development of molecular diagnosis technology, qPCR based on nucleic acid fragment detection has provided a rapid, efficient, and specific way to detect V. vulnificus (Abioye et al, 2021;Lee et al, 2021a;Álvarez-Contreras et al, 2021;Bonny et al, 2022). However, there is no official authority that can provide V. vulnificus DNA calibrations with clear quantitative values.…”

Water is a preservative of microbes

“…It is possible, however, that re‐evaluating where, why, and how water preserves life in nature can inspire new biotechological applications. For example, to develop enhanced sterilization methodologies (Craven et al ., 2021) or understand how and where unwanted human pathogens may persist in natural and built environments so that we can make knowledge‐based interventions (Cabral, 2010; Rhoads et al ., 2015; Santos et al ., 2015; Abioye et al ., 2021; Vadell et al ., 2021). In general, microorganisms are preserved in culture collections using –80°C storage or lyophilization (freeze‐drying).…”

Validity of cold storage and heat treatment on the deactivation of <i>Vibrio parahaemolyticus</i> isolated from fish meat market

“…Vibrio species have the highest rates of growth among bacteria, multiplying in response to favorable circumstances such as high temperature, salt, and dissolved oxygen nearly instantly (Abioye et al ., 2021 ).…”