Assessing pathogenicity: OmpA and AbaR gene expression in foodborne Acinetobacter baumannii from fresh fruits and vegetables in Chattogram: addressing food safety concerns

Fruits and vegetables can serve as reservoirs for Acinetobacter baumannii, a multidrug-resistant pathogen of growing concern. Its outer membrane protein A (OmpA) and autoinducer regulator (AbaR) are key virulence factors, contributing to biofilm formation, survival, and antibiotic resistance. However, little is known about the expression of these genes in foodborne isolates, particularly in Bangladesh. Fifty-six fresh produce samples from Chattogram were screened, revealing that the prevalence of A. baumannii was nearly three times higher than that of other foodborne pathogenic bacteria. To understand the full extent of the pathogenic effects of A. baumannii, we conducted a comparative gene expression analysis using Real-Time PCR. This analysis focused on two crucial pathogenic genes, OmpA and AbaR, under various culture conditions such as different carbon and nitrogen sources, pH levels, incubation times, and temperatures. A. baumannii is recognized as a pathogenic biofilm producer and a multidrug-resistant (MDR) organism. Therefore, targeting OmpA and AbaR could be a promising therapeutic approach due to their abundance and close association with virulence and bacterial survival under adverse conditions. In silico analysis further characterized the OmpA and AbaR protein, confirming its physicochemical stability along with its interactions and co-expression profiles with other proteins. This is the first report on the prevalence and expression of OmpA and AbaR genes in foodborne A. baumannii isolated from fresh produce in Bangladesh. The findings highlight the potential public health risks of contaminated fruits and vegetables and provide novel insights into virulence mechanisms, supporting the need for targeted monitoring and control strategies which will emerge a significant concern for food safety in future.