Lactobacillus reuteri and Enterococcus faecium from Poultry Gut Reduce Mucin Adhesion and Biofilm Formation of Cephalosporin and Fluoroquinolone-Resistant Salmonella enterica.

Abubakar Siddique,Maryum Arif,Erika Ganda,Amjad Ali,Muhammad Imran,Sara Azim,Fazal Adnan,Abdur Rahman

doi:10.3390/ani11123435

Abstract

Simple SummaryEnteric infections, such as Salmonella spp., are common in the poultry sector. Even though the European Union has banned the use of growth-promoting antibiotics; many countries continue to use these synthetic medications, leading to the emergence of antibiotic resistance (especially cephalosporin and fluoroquinolones) in non-typhoidal Salmonella, limiting treatment options. Probiotics are beneficial bacteria that reside in the intestine and help improve the host’s health; they are also one of the most popular antibiotic alternatives. As a result, we set out to collect lactic acid bacteria from the poultry gut that had never been fed a medicated diet and conduct in vitro probiotic studies. L. reuteri PFS4, E. faecium PFS13, and E. faecium PFS14 were screened as potential probiotic candidates. The obtained strains show good aggregation, mucin adherence, antibiofilm, and anti-salmonella activities. More research is now being conducted to determine the strain’s efficacy in commercial poultry.Non-typhoidal Salmonella (NTS) can cause infection in poultry, livestock, and humans. Although the use of antimicrobials as feed additives is prohibited, the previous indiscriminate use and poor regulatory oversight in some parts of the world have resulted in increased bacterial resistance to antimicrobials, including cephalosporins and fluoroquinolones, which are among the limited treatment options available against NTS. This study aimed to isolate potential probiotic lactic acid bacteria (LAB) strains from the poultry gut to inhibit fluoroquinolone and cephalosporin resistant MDR Salmonella Typhimurium and S. Enteritidis. The safety profile of the LAB isolates was evaluated for the hemolytic activity, DNase activity, and antibiotic resistance. Based on the safety results, three possible probiotic LAB candidates for in vitro Salmonella control were chosen. Candidate LAB isolates were identified by 16S rDNA sequencing as Lactobacillus reuteri PFS4, Enterococcus faecium PFS13, and Enterococcus faecium PFS14. These strains demonstrated a good tolerance to gastrointestinal-related stresses, including gastric acid, bile, lysozyme, and phenol. In addition, the isolates that were able to auto aggregate had the ability to co-aggregate with MDR S. Typhimurium and S. Enteritidis. Furthermore, LAB strains competitively reduced the adhesion of pathogens to porcine mucin Type III in co-culture studies. The probiotic combination of the selected LAB isolates inhibited the biofilm formation of S. Typhimurium FML15 and S. Enteritidis FML18 by 90% and 92%, respectively. In addition, the cell-free supernatant (CFS) of the LAB culture significantly reduced the growth of Salmonella in vitro. Thus, L. reuteri PFS4, E. faecium PFS13, and E. faecium PFS 14 are potential probiotics that could be used to control MDR S. Typhimurium and S. Enteritidis in poultry. Future investigations are required to elucidate the in vivo potential of these probiotic candidates as Salmonella control agents in poultry and animal feed.

Highlights

The current study aims to screen probiotic lactic acid bacteria (LAB) isolated from poultry gut for their potential inhibitory effect against MDR S
The isolates were identified as LAB based on the following characteristics: Gram-positive, catalase negative, non-motile, and cocci- or rod-shaped
The results revealed that L. reuteri PFS4 exhibited the highest percentage adhesion (92.6%), followed by E. faecium PFS13 (86.3%) and E. faecium

Summary

Introduction

Enteritidis cause economic losses in poultry by reducing growth and egg production and pose a food safety risk to humans due to potential carcass contamination in slaughterhouses [1]. Poultry products such as meat and eggs have been implicated as a major cause of non-typhoidal. The poultry industry is Pakistan’s most important agricultural activity, contributing 1.3% to the country’s gross domestic product [3]. In addition to its economic importance, the Pakistani poultry sector contributes significantly to efforts to close the gap between the demand and supply of animal protein. The poultry industry faces several challenges, including the emergence of multidrug-resistant foodborne pathogens, which can significantly endanger animal and human health and negatively impact economic output [4]. Antibiotics and vaccines are the primary control strategies to combat salmonellosis in poultry farms [5], but ever-increasing antimicrobial resistance results in antibiotics becoming less effective, while vaccine efficacy remains suboptimal [6]

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