Production systems and important antimicrobial resistant-pathogenic bacteria in poultry: a review

Abstract

Economic losses and market constraints caused by bacterial diseases such as colibacillosis due to avian pathogenic Escherichia coli and necrotic enteritis due to Clostridium perfringens remain major problems for poultry producers, despite substantial efforts in prevention and control. Antibiotics have been used not only for the treatment and prevention of such diseases, but also for growth promotion. Consequently, these practices have been linked to the selection and spread of antimicrobial resistant bacteria which constitute a significant global threat to humans, animals, and the environment. To break down the antimicrobial resistance (AMR), poultry producers are restricting the antimicrobial use (AMU) while adopting the antibiotic-free (ABF) and organic production practices to satisfy consumers' demands. However, it is not well understood how ABF and organic poultry production practices influence AMR profiles in the poultry gut microbiome. Various Gram-negative (Salmonella enterica serovars, Campylobacter jejuni/coli, E. coli) and Gram-positive (Enterococcus spp., Staphylococcus spp. and C. perfringens) bacteria harboring multiple AMR determinants have been reported in poultry including organically- and ABF-raised chickens. In this review, we discussed major poultry production systems (conventional, ABF and organic) and their impacts on AMR in some potential pathogenic Gram-negative and Gram-positive bacteria which could allow identifying issues and opportunities to develop efficient and safe production practices in controlling pathogens.

Keywords: Antibiotic-free; Antimicrobial resistance; Conventional feeding; Organic; Poultry.

Fig. 1

Bacitracin effect on broiler chicken cecal microbiota, blood metabolites, and immune gene modulation. ALP: Alkaline phosphatase; AGR: Albumin-globulin ratio; AMY: Amylase; CATH2: Cathelicidin antimicrobial peptide; MPO: Myeloperoxidase; CASP1: Caspase 1; MX1: Myxovirus resistance 1; CCR4: Chemokine receptor 4; CRP: C-reactive protein; JAK2: Janus kinase 2 "Updated from Das et al. [47]"

Fig. 2

Antibiotic resistance in Salmonella, E. coli and Camplylobacter spp. reported in major poultry production countries from 2000 to 2020. Information obtained from: Brazil [, –129], Europe [–132], USA [–139], China [–143]

Fig. 3

Schematic representation of Gram-positive and Gram-negative antimicrobial resistance mechanisms. 1. Decreased permeability of antibiotics due to outer membrane, 2. Increased expression of efflux pumps, 3. Modification/mutation of target sites (i.e. topoisomerases, ribosomes, penicillin-binding proteins (PBPs), fluoroquinolones, etc.), 4. Inactivation and modification of antibiotics via inactivating enzymes (i.e. β-lactamases, tetracycline-inactivating enzymes)