Etiology, epidemiology, pathology, and advances in diagnosis, vaccine development, and treatment ofGallibacterium anatisinfection in poultry: a review

Abstract

Gallibacterium anatis is a Gram-negative bacterium of the Pasteurellaceae family that resides normally in the respiratory and reproductive tracts in poultry. It is a major cause of oophoritis, salpingitis, and peritonitis, decreases egg production and mortality in hens thereby severely affecting animal welfare and overall productivity by poultry industries across Europe, Asia, America, and Africa. In addition, it has the ability to infect wider host range including domesticated and free-ranging avian hosts as well as mammalian hosts such as cattle, pigs and human. Evaluating the common virulence factors including outer membrane vesicles, fimbriae, capsule, metalloproteases, biofilm formation, hemagglutinin, and determining novel factors such as the RTX-like toxin GtxA, elongation factor-Tu, and clustered regularly interspaced short palindromic repeats (CRISPR) has pathobiological, diagnostic, prophylactic, and therapeutic significance. Treating this bacterial pathogen with traditional antimicrobial drugs is discouraged owing to the emergence of widespread multidrug resistance, whereas the efficacy of preventing this disease by classical vaccines is limited due to its antigenic diversity. It will be necessary to acquire in-depth knowledge on important virulence factors, pathogenesis and, concerns of rising antibiotic resistance, improvised treatment regimes, and novel vaccine candidates to effectively tackle this pathogen. This review substantially describes the etio-epidemiological aspects of G. anatis infection in poultry, and updates the recent development in understanding the pathogenesis, organism evolution and therapeutic and prophylactic approaches to counter G. anatis infection for safeguarding the welfare and health of poultry.

Extensive microbial diversity within the chicken gut microbiome revealed by metagenomics and culture

“…Such monodominance of the gut microbiome by bacterial species has been described in diseased humans ( Hildebrand et al, 2019 ; Ravi et al, 2019 ), but is surprising in the context of poultry reported as apparently healthy by their handlers. We also noted a high relative abundance of the recently described chicken pathogen Gallibacterium anatis ( Narasinakuppe Krishnegowda et al, 2020 ) in most birds (with four birds showing >5% reads assigned to this organism), despite their healthy status. Similarly, Fusobacterium mortiferum —an opportunistic pathogen of humans ( Almohaya et al, 2020 )—accounted for >10% of sequences in 11 birds, corroborating a recent report of high abundance of 16S rRNA gene sequences from this organism obtained from the chicken caecum ( Kollarcikova et al, 2019 ).…”

Antibacterial Activity of Lactic Acid Producing Leuconostoc mesenteroides QZ1178 Against Pathogenic Gallibacterium anatis

“…Owing to the emergence of widespread multidrug resistance, traditional antimicrobial drugs are not indicated for this bacterial pathogen. The efficacy of classical vaccines in preventing this disease is limited due to disease antigenic diversity ( 32 ). Common G. anatis virulence factors include the capsule, outer membrane vesicles, fimbriae, metalloproteases, and biofilm formation, etc.…”

Clonal spread of multi-resistant Gallibacterium anatis isolates among Iranian broilers and layers

“…Gallibacterium anatis is distributed globally as an important opportunistic pathogen in different poultry production systems [ 3 ]. The bacterium has been reported in several countries within Europe (Switzerland, Denmark, Germany, Norway, England, Sweden, Czech Republic, Austria), Africa (Nigeria, Egypt, Morocco), Asia (China, Taiwan, Iran, Syria, India and Japan) and American countries (USA, Canada, Colombia, Peru and Mexico) [ 3 ]. G. anatis is a Gram-negative, non-motile, encapsulated coccobacillus that constitutes part of the normal microbiota in the upper respiratory tracts and the lower genital tracts of healthy chickens [ 4 ].…”