PAKISTAN VETERINARY JOURNAL

Pak Vet J, xxxx, xx(x) xxx-xxx

Salmonella in broiler chickens: Biofilm formation, disinfectant resistance, and contribution to microbial risk in housing environments

Hanan S. Khalefa¹, Amr Elkelish²*, Marwa S. Khattab³, Amr Fouda⁴, Heba M. Salem^5,6, Soha A. Alamoudi⁷, Mohammed Musa Alzahrani², Mohammed Alghonaim², Shereen Fawzy⁸, Mohamed T. El-Saadony⁹, Asmaa M. Ali¹

¹Department of Veterinary Hygiene and Management, Faculty of Veterinary Medicine, Cairo University, Giza, 12211, Egypt; ²Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), P. O. Box: 90950, Riyadh 11623, Saudi Arabia; ³Department of Pathology, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt; ⁴Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Nasr City, Cairo, 11884, Egypt; ⁵Department of Poultry Diseases, Faculty of Veterinary Medicine, Cairo University, Giza, 12211, Egypt; ⁶Department of Diseases of Birds, Rabbits, Fish & their Care & Wildlife, School of Veterinary Medicine, Badr University in Cairo (BUC), Badr City, Cairo, Egypt; ⁷Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia; ⁸Department of Medical Microbiology, Faculty of Medicine, University of Tabuk, Tabuk 71491, Saudi Arabia; ⁹Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt

Corresponding author: aaelkelish@imamu.edu.sa (Amr Elkelish)

Abstract

Avian salmonellosis poses a significant threat to the poultry sector. The ability of Salmonella to form biofilms enhances its long-term persistence in poultry houses, thereby increasing the risk of zoonotic transmission. Therefore, this study aims to identify the prevalent Salmonella species in various broiler chicken farms and conduct a risk analysis for their occurrence. The poultry samples, which included 220 bird organs and environmental samples, had a Salmonella isolation rate of 4.45%. From the examined bird and environmental samples, 10 Salmonella isolates were recovered (seven from bird samples and three from environmental samples). The ten Salmonella isolates were identified in this investigation using serological analysis. The study revealed the presence of five different serotypes: S. Enteritidis (40%), S. Kentucky (30%), S. Typhimurium (10%), S. Infants (10%), and S. Gueuletapee (10%). On the experimental level, the tube adherence test confirmed biofilm formation on the inner surface of the test tubes, resulting in 20% of the Salmonella isolates exhibiting a strong positive reaction, 50% displaying a moderate response, and 30% showing a weak reaction. Additionally, our second objective is to conduct an in vitro assessment of the S. Enteritidis strain's ability to form biofilms on PVC coupons, given its zoonotic significance and detrimental effects on chickens. Additionally, the biofilm's susceptibility to various disinfectants was evaluated. The results show that Virkon S® (1% wt./vol) and H₂O₂ (1.0% vol/vol) were able to reduce the count of microbes on the PVC surface by 5.6 and 5.8 log, respectively. The effectiveness of disinfectants in eliminating biofilm on contaminated surfaces varies depending on factors such as concentration, duration of contact, active ingredients, biofilm age, and environmental variables that simulate real situations.

To Cite This Article: Khalefa HS, Elkelish A, Khattab MS, Fouda A, Salem HM, Alamoudi SA, Alzahrani MM, Alghonaim M, Fawzy ES, Saadony MT, and Ali AM, 2025. Salmonella in broiler chickens: Biofilm formation, disinfectant resistance, and contribution to microbial risk in housing environments. Pak Vet J. http://dx.doi.org/10.29261/pakvetj/2025.242

Abstract

ISSN 0253-8318 (Print)ISSN 2074-7764 (Online)

ISSN 0253-8318 (Print)
ISSN 2074-7764 (Online)