Isolation, characterization, and antibiotic sensitivity assessment of Gallibacterium anatis biovar haemolytica, from diseased Egyptian chicken flocks during the years 2013 and 2015

Abstract

Gallibacterium anatis biovar haemolytica constitutes a part of the normal microflora in the upper respiratory and genital tracts of healthy chickens, but it is also associated with different pathological conditions. In the current study, 102 commercial chicken flocks suffering from respiratory disease and/or drop in egg production were investigated for the presence of G. anatis during 2013 and 2015. These flocks comprised 8 breeder, 32 layer, and 62 broiler flocks. By culture method, 20 flocks were found positive: one isolate derived from broiler breeders, 6 isolates from layers, and 13 isolates from broilers. G. anatis biovar haemolytica was identified by phenotyping and PCR. Additionally, partial genome sequencing of 11 isolates (5 layer isolates of 2013 and 6 broiler isolates of 2015) based on 16S rRNA and 23S rRNA gene sequences was performed and revealed 96.5% to 100% genetic relatedness. Antibiotic sensitivity of these isolates revealed that the 2013 isolates were highly susceptible to florfenicol while the isolates of 2015 were highly susceptible to cefotaxime. Gallibacterium anatis biovar haemolytica is a newly introduced bacteria in Egypt causing salpingitis, peritonitis, drop in egg production, and/or respiratory signs.

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

“…Gallibacterium have been reported across the world, such as European countries including Switzerland, Denmark, Germany, Norway, England, Sweden, Czech Republic and Austria (Mr az et al 1976;Bisgaard 1977;Mirle et al 1991;Neubauer et al 2009;Jones et al 2013); African countries like Nigeria, Egypt, Morocco (Addo & Mohan 1985;Elbestawy et al 2018;Nassik et al 2019); Asian countries including China, Taiwan, Iran, Syria, India and Japan (Suzuki et al 1996;Guo 2011;Huangfu et al 2012;Ataei et al 2017;Zhang et al 2017;Singh et al 2018); American countries such as the USA, Canada, Colombia, Peru and Mexico (Hacking & Pettit 1974;Shaw et al 1990;Bojesen et al 2008;Mendoza et al 2014;Paudel, Liebhart, Aurich, et al 2014;Ch avez et al 2017); and Australia (Jordan et al 2005). G. anatis, particularly biovar hemolytica, has recently gained importance due to its ability to cause both respiratory and reproductive infections, and its occurrence in countries on various continents including Europe, Asia, America, and Africa (Neubauer et al 2009).…”

“…G. anatis became known as an intriguing agent when it was isolated from clinically affected broiler and breeder flocks. This pathogen has the ability to colonize the upper respiratory tract of broilers and cause no symptoms or mild respiratory signs like rales, coughing, cold, dyspnea, shaking heads, mild swelling of head, and nasal discharge, whereas other signs like diarrhea, anorexia, and general emaciation have also been reported (Bojesen et al 2008;El-Adawy et al 2018;Elbestawy et al 2018). G. anatis causes a 3-18% decrease in egg production (Jones et al 2013).…”

“…G. anatis causes a 3-18% decrease in egg production (Jones et al 2013). In breeders, G. anatis infection is associated with a cumulative mortality rate ranging from 0.06 to 4.9% (Elbestawy et al 2018). Osuna Ch avez et al (2017) recently collected twenty-three isolates of G. anatis from commercial laying hens which had respiratory and reproductive clinical signs in the Sonora region of M exico.…”

“…Although G. anatis infection can generally be treated with antimicrobials, some non-responsive cases and recurrence have been reported El-Adawy et al 2018;Hess et al 2019). Multi-drug resistant strains of G. anatis are frequently reported and these strains show resistance to sulfonamides, novobiocin, tylosin, clindamycin, tetracycline, and penicillin (Jones et al 2013;El-Adawy et al 2018;Elbestawy et al 2018). reported the majority of G. anatis strains (65%) to be multidrug resistant in an in vitro study and only two strains were found to be susceptible to all antibiotics/drugs tested.…”

“…Approximately 93% of field strains tested were reported to be resistant to sulfamethoxine, 93% to spectinomycin, 87% to tylosin, and 80% to oxytetracycline. Since antibiotic susceptibility of strains constantly changes, regular in vitro evaluation of the isolates is needed (Elbestawy et al 2018). A report by Ch avez (2017) described marked resistance to penicillin, tylosin, lincomycin, ampicillin, enrofloxacin, oxytetracycline, norfloxacin, and cephalexin; yet sensitive to ceftiofur (73%) and florfenicol (68%).…”