Prevalence of Biofilm Formation and Wide Distribution of Virulence Associated Genes among Vibrio spp. Strains Isolated from the Monastir Lagoon, Tunisia

Spotlight on the epidemiology and antimicrobial susceptibility profiles of Vibrio species in the MENA region, 2000-2023

Recent cholera outbreaks in many countries in the Middle East and North Africa (MENA) region have raised public health concerns and focused attention on the genus Vibrio. However, the epidemiology of Vibrio species in humans, water, and seafood is often anecdotal in this region. In this review, we screened the literature and provided a comprehensive assessment of the distribution and antibiotic resistance properties of Vibrio species in different clinical and environmental samples in the region. This review will contribute to understanding closely the real burden of Vibrio species and the spread of antibiotic-resistant strains in the MENA region. The overall objective is to engage epidemiologists, sanitarians and public health stakeholders to address this problem under the One-health ethos.

A meta-analysis on the distribution of pathogenic Vibrio species in water sources and wastewater in Africa

Vibrio species are waterborne ubiquitous organisms capable of causing diseases in humans and animals and the occurrence of infections caused by pathogenic Vibrio species among humans have increased globally. This reemergence is attributed to environmental impacts such as global warming and pollution. Africa is most vulnerable to waterborne infections caused by these pathogens because of lack of good water stewardship and management. This study was carried out to provide an in-depth inquiry into the occurrence of pathogenic Vibrio species in water sources and wastewater across Africa. In this regard, a systematic review and meta-analysis was conducted by searching five databases: PubMed, ScienceDirect, Google Scholar, Springer Search and African Journals Online (AJOL). The search yielded 70 articles on pathogenic Vibrio species presence in African aquatic environments that fit our inclusion criteria. Based on the random effects model, the pooled prevalence of pathogenic Vibrio species in various water sources in Africa was 37.6 % (95 % CI: 27.7-48.0). Eighteen countries were represented by the systematically assessed studies and their nationwide prevalence in descending order was: Nigeria (79.82 %), Egypt (47.5 %), Tanzania (45.8 %), Morocco (44.8), South Africa (40.6 %), Uganda (32.1 %), Cameroon (24.5 %), Burkina Faso (18.9 %) and Ghana (5.9 %). Furthermore, 8 pathogenic Vibrio species were identified across water bodies in Africa with the highest detection for V. cholerae (59.5 %), followed by V. parahaemolyticus (10.4 %), V.alginolyticus (9.8 %), V. vulnificus (8.5 %), V. fluvialis (6.6 %), V. mimicus (4.6 %), V. harveyi (0.5 %) and V. metschnikovii (0.1 %). Evidently, pathogenic Vibrio species occurrence in these water sources especially freshwater corroborates the continuous outbreaks observed in Africa. Therefore, there is an urgent need for proactive measures and continuous monitoring of water sources used for various purposes across Africa and proper treatment of wastewater before discharge into water bodies.

Rapid and Visualized Detection of Virulence-Related Genes of Vibrio cholerae in Water and Aquatic Products by Loop-Mediated Isothermal Amplification

ABSTRACT

Vibrio cholerae can cause pandemic cholera in humans. The bacterium resides in aquatic environments worldwide. Continuous testing of V. cholerae contamination in water and aquatic products is imperative for food safety control and human health. In this study, a rapid and visualized method was developed for the first time based on loop-mediated isothermal amplification (LAMP) for detection of the important virulence-related genes ace, zot, cri, and nanH for toxins and the infectious process of V. cholerae. Three pairs of molecular probes targeting each of these genes were designed and synthesized. The one-step LAMP reaction was conducted at 65°C for 40 min. Positive results were inspected by the production of a light green color under visible light or green fluorescence under UV light (302 nm). Limit of detection of the LAMP method ranged from 1.85 to 2.06 pg per reaction of genomic DNA or 2.50 × 100 to 4.00 × 102 CFU per reaction for target genes of cell culture of V. cholerae, which was more sensitive than standard PCR. Inclusivity and exclusivity of the LAMP method were 100% for all target genes. The method showed similar high efficiency to a certain extent in rapid testing of spiked or collected specimens of water and aquatic products. Target genes were detected by absence from all water samples from various sources. However, high occurrences of the nanH gene were observed in intestinal samples derived from four species of fish and one species of shellfish, indicating a risk of potentially toxic V. cholerae in commonly consumed aquatic products. The results in this study provide a potential tool for rapid and visualized detection of V. cholerae in water and aquatic products.

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