Antibiotic Resistance, Virulence Gene Detection, and Biofilm Formation in Aeromonas spp. Isolated from Fish and Humans in Egypt

Abstract

The genus Aeromonas is widely distributed in aquatic environments and is recognized as a potential human pathogen. Some Aeromonas species are able to cause a wide spectrum of diseases, mainly gastroenteritis, skin and soft-tissue infections, bacteremia, and sepsis. The aim of the current study was to determine the prevalence of Aeromonas spp. in raw fish markets and humans in Zagazig, Egypt; identify the factors that contribute to virulence; determine the isolates’ profile of antibiotic resistance; and to elucidate the ability of Aeromonas spp. to form biofilms. The examined samples included fish tissues and organs from tilapia (Oreochromis niloticus, n = 160) and mugil (Mugil cephalus, n = 105), and human skin swabs (n = 51) and fecal samples (n = 27). Based on biochemical and PCR assays, 11 isolates (3.2%) were confirmed as Aeromonas spp. and four isolates (1.2%) were confirmed as A. hydrophila. The virulence genes including haemolysin (hyl A) and aerolysin (aer) were detected using PCR in A. hydrophila in percentages of 25% and 50%, respectively. The antimicrobial resistance of Aeromonas spp. was assessed against 14 antibiotics comprising six classes. The resistance to cefixime (81.8%) and tobramycin (45.4%) was observed. The multiple antibiotic resistance (MAR) index ranged between 0.142–0.642 with 64.2% of the isolates having MAR values equal to 0.642. Biofilm formation capacity was assessed using a microtiter plate assay, and two isolates (18.1%) were classified as biofilm producers. This study establishes a baseline for monitoring and controlling the multidrug-resistant Aeromonas spp. and especially A. hydrophila in marine foods consumed in our country to protect humans and animals.

Cross-sectional analysis of risk factors associated with Mugil cephalus in retail fish markets concerning methicillin-resistant Staphylococcus aureus and Aeromonas hydrophila

“…human sickness as well as a fish pathogen (Stratev and Odeyemi, 2016). The prevalence of A. hydrophila in fish (37.72%) was higher than that in mullet fish (1.2%; El-Hossary et al, 2023) but lower than the 54.2% reported by Abd El-Tawab et al ( 2021). The highest level of A. hydrophila was identified in washing water, followed by fish handlers, fish skin, knives, chopping boards, and fish muscle.…”

“…In comparison, our discovery was higher than the reported 3.2% for Aeromonas spp. in Egyptian mullet fish by El-Hossary et al (2023). Most Aeromonas species were found in washing water, followed by fish skin, knives, chopping boards, fish handlers, and fish muscle.…”

Molecular characterization of Aeromonas hydrophila detected in Channa marulius and Sperata sarwari sampled from rivers of Punjab in Pakistan

“…The main reason behind the high prevalence of A. hydrophila was contamination caused by marketing and transportation. Similarly, El-Hossary, [79] detected aerolysin (aerA) and hemolysin (hylA) genes in A. hydrophila isolated from infected Nile tilapia (Oreochromis niloticus) collected from local fish markets in Egypt. They found A. hydrophila in 28.8% of market fish samples.…”

Prevalence of Extended-Spectrum β-Lactamases (ESBLs) Producing Aeromonas spp. Isolated from Lamellidens marginalis (Lamark, 1819) of Sewage-Fed Wetland: A Phenotypic and Genotypic Approach

“…The MARI was determined as per El-Hossary et al [27] using the formula MARI = a/b, where 'a' denotes the count of antibiotics to which the tested Aeromonas isolate exhibited resistance, and 'b' denotes the total number of antibiotics included in the assessment for the tested Aeromonas isolate. In the case of a specific Aeromonas isolate, the RI was defined as a quantification representing the count of antibiotics to which the isolate displayed either intermediate or full resistance.…”