Gallibacterium anatis is an opportunistic bacteria inducing a range of clinical signs in poultry. Gallibacterium anatis strains show multidrug resistance to antibacterial substances. The purpose of this study was to examine the susceptibility of G. anatis biovar haemolytica isolates collected from the respiratory, reproduction and gastrointestinal tracts of chickens to different antibiotics from various classes.

Nile tilapia aquaculture is a fast-growing industrial sector in Egypt. However, the progress of this industry is hindered by many challenges as poor water quality and associated bacterial infections. Aeromonas hydrophila is an important zoonotic waterborne aquatic pathogen responsible for severe outbreaks in tilapia culture so the current study aimed to investigate the prevalence of Aeromonas hydrophila in tilapia fish and their aquaculture water, the fish and water samples were collected from three farms located in Assiut and Minia Governorates, Egypt. Aeromonas hydrophila was isolated from tilapia five organs including liver, kidney, intestine, spleen and gills with a percentage of 7.1%, 6.5%, 9.1%, 5.1%, 11.7%, receptively, and from water samples with 59.7%. The isolates were molecularly confirmed as Aeromonas hydrophila in 70.9% and 82.4% of the tested isolates using 16s RNA and gyr-β primers, respectively. Aeromonas hydrophila isolates revealed a marked resistance for the tested antibiotics; amoxicillin and novobiocin (100%), streptomycin (71.4 %), chloramphenicol (57%), doxycycline and trimethoprim/Sulphamethoxazole (50%), colistin (43%), ciprofloxacin and norfloxacin (14%). The isolates showed multiple antibiotic resistance indexes ranging from 0.3 to 1. The present study highlights the Aeromonas hydrophila resistance and virulence, tilapia aquaculture health hazard to the human population, so adequate control measures should be applied. Furthermore, there is an essential need to promote an alternative non-antibiotic control in farmed fish.

The current study was carried to investigate the prevalence of Campylobacter jejuni in broiler chicks in Dakhalia province. Besides, the effects of carvacol and thymol essential oils (EO), as a continuous drinking water treatment for protection against Campylobacter jejuni challenge in commercial broiler chickens were assessed. Four hundred and fifty samples were collected from 50 healthy bird, 100 freshly dead birds and 100 diseased birds. Out of 450 examined samples, 22.44 % (101̸450) were positive for Campylobacter jejuni. These isolates were sensitive for neomycin, amoxicillin and ceftriaxone. Random assignment of 180 one-day old chicks into 6 groups (30 birds/group in 3 replicates) arranged as follows: G1 as non-challenged group, G2 was challenged with C. jejuni while G3, and G4 were challenged with C. jejuni and continuously supplemented with carvacol and thymol, respectively, in drinking water from day 7. G5 was challenged with C. jejuni and had the two essential oils continuously in drinking water from day 7. G6 was challenged with Campylobacter jejuni and treated with neomycin (15 mg/kg B.W). Our results showed that the combination of essential oils was more effective in mitigating the devastating effects of Campylobacter jejuni challenge in broilers than using one EO alone. Growth performance represented by body weight gain, and feed conversion ratio were significantly (p<0.05) improved. Campylobacter jejuni shedding was reduced in the challenged treated groups. Also, the biochemical profile was improved. In addition, the level of the pro-inflammatory cytokines IL-1β and IL-6 were significantly down regulated in the challenged-treated group. In conclusion, it is highly recommended to use carvacol and thymol EO either alone or in a combination to improve the body performance and to protect broilers against Campylobacter jejuni.