Vibriosis and Aeromonas infection in shrimp: Isolation, sequencing, and control

Abstract

Background and Aim: Shrimp is one of the most commonly consumed types of seafood. It is a very nutritious healthy food. Shrimp is low in calories and rich in protein and healthy fats. It also contains a treasure trove of vitamins and minerals. On the negative side, it may be affected by many bacterial diseases which affect its health. Furthermore, it may be incriminated as a vector of foodborne illnesses that range from mild gastrointestinal upset to life-threatening diseases. This study was designed to assess the clinical picture and zoonotic importance of vibriosis and Aeromonas infection in live shrimp and to study the antibacterial effect of citric acid (lemon juice) and acetic acid (vinegar) on these pathogens. Materials and Methods: A total of 170 live shrimp (Metapenaeus monoceros) samples were collected from Suez City, Egypt. The samples were examined clinically, and then, they were enriched into alkaline peptone water and cultivated on thiosulfate-citrate-bile salts-sucrose agar and ampicillin MacConkey agar for the isolation of Vibrio and Aeromonas species, respectively. The recovered isolates were confirmed biochemically and genotypically using duplex polymerase chain reaction (PCR) and sequencing. The germicidal effects of vinegar and lemon on artificially contaminated shrimp samples with Aeromonas hydrophila and Vibrio parahaemolyticus at different times (0.25, 1, 1.5, and 24 h) and temperatures (5° and 30°C) were studied. Results: The results revealed that some of the infected shrimp were hypoxic, lethargic with abnormal swimming behavior. In most cases, body appendages, telsons, uropods, and gills took black coloration. In addition, the hepatopancreas appeared soft, swollen, and congested. The prevalence rates of vibriosis in each of the musculature and hepatopancreas were 4.7%, while the prevalence rates of Aeromonas infection in the musculature and hepatopancreas were 11.8% and 11.2%, respectively. Duplex PCR showed that Aeromonas isolates gave double bands: 237 bp specific for gcat and 500 bp specific for 16S rRNA, while Vibrio spp. and Plesiomonas shigelloides isolates gave single band at 500 bp. The effect of organic acid treatment showed that acetic acid (vinegar 5%) had increasing reduction rates that reached its maximum level after 24 h; where it caused (100% inhibition) for A. hydrophila at both temperatures and (33.63% and 60% inhibition) for V. parahaemolyticus at refrigerator and room temperatures, respectively. Moreover, acetic acid was more effective at room temperature than at refrigerator temperature. Concerning the effect of lemon juice (citric acid), it was more effective than acetic acid at short marination (0.25 and 1 h) at both temperatures for the two pathogens. Moreover, lemon was more effective at refrigerator temperature than at room temperature at the same aforementioned time. The difference between the reduction effects of the two acids on both pathogens was statistically significant (p<0.0001). Conclusion: Overall, the examined shrimp samples were found to be vectors for Vibrio and Aeromonas spp. Application of hygienic measures during handling and cooking of shrimp should be esteemed. The organic acid treatment trial showed that vinegar and lemon juice can be used as a safe and economic method to limit the microbial contamination in seafood.

Bacterial Shrimp Disease in Iraqi Marine Waters

“…Table 3 showed that among the 116 examined samples, the overall prevalence of Aeromonas was 21.55% (25 samples). These results are higher than what was recorded by Fadel & El-Lamie (2019) who recorded prevalence of infection as 16 (9.41%) of 170 tested shrimp.…”

“…On the negative side, many bacterial diseases infect them to affect their health and compromise the hygiene. They can also be charged as a vector of foodborne infections ranging from mild gastrointestinal upset to life-threatening diseases (Fadel & El-Lamie, 2019).…”

Presence and Virulence Potential of Aeromonas hydrophila in Selected Water Sources for Household Consumption in Makurdi, Benue State

“…The presence of this gene is a strong evidence of pathogenic potential of A. hydrophila isolates [22,23,38]. The production of these virulence properties have been known to contribute to pathogenesis and disease in humans [8,38]. The pathogenesis is that of a toxicoinfection with symptoms including fever, diarrhoea and abdominal pain [39].…”

“…Reports show that a greater risk of infection occurs in young children, elderly people and immune compromised patients [7]. Virulence in A. hydrophila is multifactorial, with disease resulting from the production of various virulent factors including haemolytic, cytotoxic and enterotoxigenic properties [8].…”

The DNA binding domain of theVibrio vulnificusSmcR transcription factor is flexible and recognizes diverse DNA sequences

“…Upon entering a host, bacteria need to upregulate genes required for colonization and establishing an infection, including cell surface appendages for attachment to surfaces, secretion systems for delivery of toxins, and enzymes for digestion of macromolecules for nutrient acquisition (1-5). Vibrios are Gram-negative bacteria that are found in the marine environment, and many of these bacteria are also pathogens of a variety of fish and shellfish (6)(7)(8)(9)(10). Notably, some vibrios are potent human pathogens such as Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus.…”