Objectives: The research was carried out on broilers to determine the efficacy of probiotics (Bacillus subtilis and Saccharomyces boulardii combined) supplementation on growth perfor­mances, nutrient retention (metabolizable energy, dry matter, and crude protein), and cecal microbiology (Bifidobacteria spp., Clostridium spp., and coliforms).  Materials and Methods: A total of 160 broiler chicks (day-old) were selected and differentiated randomly into 4 groups (T0, T1, T2, and T3) (40 × 4) comprising 40 birds in every single group. The control group (T0) was fed commercial broiler feed only and the other three groups, referred to as treatment groups (T1, T2, and T3), were treated with 1 gm ciprofloxacin, 1 gm probiotic, and 1 gm probiotic plus 0.5 gm enzyme, respectively, in per liter of fresh dietary water 8 h daily for 7 days in each phase. Experimental trials were divided into 2 phases, the starter phase from day 0 to 21 and the finisher phase from day 22 to 35.  Results: Bodyweight gain and nutrient retention in experimental broiler birds in treatment groups were significantly (p < 0.05) higher than the control group. Overall body weight gain and nutrient retention of broiler chicks in treatment groups T2 and T3 were better than T1. From day 22 to 35, cecal Clostridium and coliform bacterial load counts were significantly lower p < 0.01, p < 0.05, and p < 0.01, respectively, in T1, T2, and T3 treatments than T0. Overall, Clostridium and coliform bacterial counts in the birds of treatment group T2 were significantly lower (p < 0.05) than T0.  Conclusion: The probiotics, in addition to enzyme supplementation, had suitable influence effects on growth performance of broilers, birds retention of nutrient, and microfloral count in birds’ cecum. J. Adv. Vet. Anim. Res., 8(4): 534-539, December 2021 http://doi.org/10.5455/javar.2021.h543

Objectives: The research was carried out on broilers to determine the efficacy of probiotics (Bacillus subtilis and Saccharomyces boulardii combined) supplementation on growth performances, nutrient retention (metabolizable energy, dry matter, and crude protein), and cecal microbiology (Bifidobacteria spp., Clostridium spp., and coliforms). Materials and Methods: A total of 160 broiler chicks (day-old) were selected and differentiated randomly into 4 groups (T0, T1, T2, and T3) (40 × 4) comprising 40 birds in every single group. The control group (T0) was fed commercial broiler feed only and the other three groups, referred to as treatment groups (T1, T2, and T3), were treated with 1 gm ciprofloxacin, 1 gm probiotic, and 1 gm probiotic plus 0.5 gm enzyme, respectively, in per liter of fresh dietary water 8 h daily for 7 days in each phase. Experimental trials were divided into 2 phases, the starter phase from day 0 to 21 and the finisher phase from day 22 to 35. Results: Bodyweight gain and nutrient retention in experimental broiler birds in treatment groups were significantly (p < 0.05) higher than the control group. Overall body weight gain and nutrient retention of broiler chicks in treatment groups T2 and T3 were better than T1. From day 22 to 35, cecal Clostridium and coliform bacterial load counts were significantly lower p < 0.01, p < 0.05, and p < 0.01, respectively, in T1, T2, and T3 treatments than T0. Overall, Clostridium and coliform bacterial counts in the birds of treatment group T2 were significantly lower (p < 0.05) than T0. Conclusion: The probiotics, in addition to enzyme supplementation, had suitable influence effects on growth performance of broilers, birds retention of nutrient, and microfloral count in birds cecum. [J Adv Vet Anim Res 2021; 8(4.000): 534-539]

Objective: The influence of the degree of pigmentation, shine, weight, and form index on the hatchability rate of quail eggs (Coturnix coturnix japonica) was examined.  Materials and Methods: Three thousand three hundred eggs were incubated after they were classified according to the degree of shell pigmentation: high (HP), medium (MP), and low (LP); shell shine: shiny (SS), and opaque; Egg weight: <11, 11.0–11.9, 12.0–12.9, and >13 gm; form index: <78% and >78%. The Mann–Whitney non-parametric test for independent samples was used to evaluate hatching data.  Results: Hatchability was best in eggs with HP and SS (p < 0.05): 69.2% and 75.7%, respectively; eggs with MP had the lowest hatchability rate (63.1%). The highest risk of embryo death (17.8%) was observed in eggs containing LP (p < 0.05). Eggs weighing between 12 and 12.9 gm had the highest hatchability rate (p < 0.05) (79.11%). Eggs with a form index >78% had the highest hatch­ability rate (p < 0.05) (67.62%).  Conclusions: HP, MP shell eggs, and SS eggs with a weight of between 12.0 and 12.9 gm and a shape index of greater than 78% have a higher hatchability rate. J. Adv. Vet. Anim. Res., 8(4): 629–634, December 2021 http://doi.org/10.5455/javar.2021.h554

Objective: The influence of the degree of pigmentation, shine, weight, and form index on the hatchability rate of quail eggs (Coturnix coturnix japonica) was examined. Materials and Methods: Three thousand three hundred eggs were incubated after they were classified according to the degree of shell pigmentation: high (HP), medium (MP), and low (LP); shell shine: shiny (SS), and opaque; Egg weight: 13 gm; form index: 78%. The MannWhitney non-parametric test for independent samples was used to evaluate hatching data. Results: Hatchability was best in eggs with HP and SS (p < 0.05): 69.2% and 75.7%, respectively; eggs with MP had the lowest hatchability rate (63.1%). The highest risk of embryo death (17.8%) was observed in eggs containing LP (p < 0.05). Eggs weighing between 12 and 12.9 gm had the highest hatchability rate (p < 0.05) (79.11%). Eggs with a form index >78% had the highest hatch¬ability rate (p < 0.05) (67.62%). Conclusions: HP, MP shell eggs, and SS eggs with a weight of between 12.0 and 12.9 gm and a shape index of greater than 78% have a higher hatchability rate. [J Adv Vet Anim Res 2021; 8(4.000): 629-634]

Objective: Duck virus enteritis is a severe viral disease that kills ducks and swans worldwide. The clinical manifestations, gross pathology, molecular detection, and characterization of the duck virus enteritis virus (DVEV) in Australian black swans at a safari park in Bangladesh were described in this case report. Materials and Methods: On a safari park in Bangladesh, an Australian black swan flock exhibited clinical signs of anorexia, greenish watery diarrhea, increased thirst, partial paralysis, and death. Postmortem examinations of deceased swans revealed extensive pathological abnormalities in the trachea, liver, and spleen. To isolate DVEV, a viral inoculum produced from the liver and spleen of dead swans was implanted into 9–13-day-old embryonated duck eggs via the chorioallantoic membrane (CAM) route. DVEV was confirmed using a polymerase chain reaction (PCR) assay. Phylogenetic analysis was used to determine the genetic relationship between the DVEV isolates from Australian black swans, and 16 DVEV isolates previously described in the GenBank. Results: Hemorrhage was noted in the annular ring of the trachea, as well as an enlarged and hemorrhagic liver and spleen. The PCR assay amplified a 446-bp fragment of the DVEV DNA polymerase gene in the liver, spleen, and CAM homogenates. The phylogenetic analysis found that the DVEV isolates from swans were comparable to those from Bangladesh, India, Vietnam, China, Germany, the USA, and Egypt. Conclusion: According to the findings of this study, the DVEV was the cause of illness and mortality in an Australian black swan flock. J. Adv. Vet. Anim. Res., 8(4): 557-562, December 2021 http://doi.org/10.5455/javar.2021.h545

Objective: Duck virus enteritis is a severe viral disease that kills ducks and swans worldwide. The clinical manifestations, gross pathology, molecular detection, and characterization of the duck virus enteritis virus (DVEV) in Australian black swans at a safari park in Bangladesh were described in this case report. Materials and Methods: On a safari park in Bangladesh, an Australian black swan flock exhibited clinical signs of anorexia, greenish watery diarrhea, increased thirst, partial paralysis, and death. Postmortem examinations of deceased swans revealed extensive pathological abnormalities in the trachea, liver, and spleen. To isolate DVEV, a viral inoculum produced from the liver and spleen of dead swans was implanted into 913-day-old embryonated duck eggs via the chorioallantoic membrane (CAM) route. DVEV was confirmed using a polymerase chain reaction (PCR) assay. Phylogenetic analysis was used to determine the genetic relationship between the DVEV isolates from Australian black swans, and 16 DVEV isolates previously described in the GenBank. Results: Hemorrhage was noted in the annular ring of the trachea, as well as an enlarged and hemorrhagic liver and spleen. The PCR assay amplified a 446-bp fragment of the DVEV DNA polymerase gene in the liver, spleen, and CAM homogenates. The phylogenetic analysis found that the DVEV isolates from swans were comparable to those from Bangladesh, India, Vietnam, China, Germany, the USA, and Egypt. Conclusion: According to the findings of this study, the DVEV was the cause of illness and mortality in an Australian black swan flock. [J Adv Vet Anim Res 2021; 8(4.000): 557-562]

Green sea turtles are one of the two species of marine turtles known to nest in the Maldives. The prevalent time of nesting seems to be inconsistent throughout the island nation. In this study, sea turtle nesting activity was monitored on the island of Coco Palm Dhuni Kolhu in Baa Atoll over a period of 12 months. A total of 13 nests were confirmed with a median hatching success rate of 89.58% as ascertained by nest excavation. In one of the nests, a severely deformed hatchling with polycephaly, an opening in the neck area and a lordotic spine was found, and we investigated in detail with radiographic images and a necropsy. Our findings support the importance of consistent nesting activity and nest monitoring efforts in the country as a basis for conservation efforts.

Green sea turtles are one of the two species of marine turtles known to nest in the Maldives. The prevalent time of nesting seems to be inconsistent throughout the island nation. In this study, sea turtle nesting activity was monitored on the island of Coco Palm Dhuni Kolhu in Baa Atoll over a period of 12 months. A total of 13 nests were confirmed with a median hatching success rate of 89.58% as ascertained by nest excavation. In one of the nests, a severely deformed hatchling with polycephaly, an opening in the neck area and a lordotic spine was found, and we investigated in detail with radiographic images and a necropsy. Our findings support the importance of consistent nesting activity and nest monitoring efforts in the country as a basis for conservation efforts.

Bovine tuberculosis (bTB) is a zoonotic, infectious, chronic and contagious disease, caused by Mycobacterium bovis that mainly affects cattle. This pathology has a negative impact on animals and animal products trade. Unfortunately, in Burkina Faso where agriculture and livestock sectors represent around 80% of the socio-economic activities, the real situation of the disease is not well known especially in small ruminants and swine. Thus, our study focused on both the epidemiology and the microbiological diagnosis of tuberculosis (TB) in small ruminants and pigs slaughtered at Bobo-Dioulasso abattoir. A prospective study was conducted between August 2017 and December 2017. Epidemiological data collection was performed during routine meat inspection; moreover, samples were taken and transported to the Bacteriology laboratory of Centre Muraz for microbiological analyses. This diagnosis consisted in search of Acid Fast Bacilli (AFB) using the hot Ziehl–Neelsen staining. Out of a total of 14 648 small ruminants and 2430 pigs slaughtered during the study period, 156 and 17 had lesions suggestive of bTB with prevalence of 1.07% and 0.7%, respectively. Females and those between 2 and 4 years old were mainly infected. The most affected organs were: lungs, liver, spleen and lymph nodes. Finally, microscopy revealed 43.35% (75/173) of positive cases for AFB. These results confirm the presence of bTB in small ruminants and pigs in Burkina Faso. Efforts must still be made in the fight against this zoonosis in order to limit its economic and public health impacts.

Bovine tuberculosis (bTB) is a zoonotic, infectious, chronic and contagious disease, caused by Mycobacterium bovis that mainly affects cattle. This pathology has a negative impact on animals and animal products trade. Unfortunately, in Burkina Faso where agriculture and livestock sectors represent around 80% of the socio-economic activities, the real situation of the disease is not well known especially in small ruminants and swine. Thus, our study focused on both the epidemiology and the microbiological diagnosis of tuberculosis (TB) in small ruminants and pigs slaughtered at Bobo-Dioulasso abattoir. A prospective study was conducted between August 2017 and December 2017. Epidemiological data collection was performed during routine meat inspection; moreover, samples were taken and transported to the Bacteriology laboratory of Centre Muraz for microbiological analyses. This diagnosis consisted in search of Acid Fast Bacilli (AFB) using the hot Ziehl–Neelsen staining. Out of a total of 14 648 small ruminants and 2430 pigs slaughtered during the study period, 156 and 17 had lesions suggestive of bTB with prevalence of 1.07% and 0.7%, respectively. Females and those between 2 and 4 years old were mainly infected. The most affected organs were: lungs, liver, spleen and lymph nodes. Finally, microscopy revealed 43.35% (75/173) of positive cases for AFB. These results confirm the presence of bTB in small ruminants and pigs in Burkina Faso. Efforts must still be made in the fight against this zoonosis in order to limit its economic and public health impacts.

There are limited data on the efficacy of antiparasitic treatments and husbandry methods to control nematode infections in captive populations of African green monkeys (AGMs), Chlorocebus sabaeus. In faecal egg count (FEC) tests, 10 of the 11 (91%) adult male AGMs captured from the large feral population on the island of St Kitts had evidence of nematode infections, mostly Capillaria (8/11, 73%), Trichuris trichiura (7/11, 64%) and strongylid species (7/11, 64%) specifically (hookworm and Trichostrongylus, 50/50), but also Strongyloides fuelleborni (1/11, 9%). When kept in individual cages with cleaning and feeding regimens to prevent reinfections and treated concurrently with ivermectin (300 µg/kg, given subcutaneously) and albendazole (10 mg/kg, given orally) daily for 3 days, 60% (6/10) of the AGMs were negative at a follow-up FEC at 3 months and by FEC and necropsy at the end of the study 5–8 months later. One monkey appeared to have been reinfected with T. trichiura after being negative by FEC at 3 months post-treatment. Four AGMs were positive for T. trichiura at the 3 month FEC follow-up but were negative at the end of the study after one further treatment regimen. Although initially being cleared of Capillaria following treatment, three AGMs were found to be infected at the end of the study. The ivermectin and albendazole treatment regimen coupled with good husbandry practices to prevent reinfections effectively controlled nematode infections in captive AGMs.

Funding was provided by the Ross University School of Veterinary Medicine via the One Health Center for Zoonoses and Tropical Veterinary Medicine. | There are limited data on the efficacy of antiparasitic treatments and husbandry methods to control nematode infections in captive populations of African green monkeys (AGMs), Chlorocebus sabaeus. In faecal egg count (FEC) tests, 10 of the 11 (91%) adult male AGMs captured from the large feral population on the island of St Kitts had evidence of nematode infections, mostly Capillaria (8/11, 73%), Trichuris trichiura (7/11, 64%) and strongylid species (7/11, 64%) specifically (hookworm and Trichostrongylus, 50/50), but also Strongyloides fuelleborni (1/11, 9%). When kept in individual cages with cleaning and feeding regimens to prevent reinfections and treated concurrently with ivermectin (300 mu g/kg, given subcutaneously) and albendazole (10 mg/kg, given orally) daily for 3 days, 60% (6/10) of the AGMs were negative at a follow-up FEC at 3 months and by FEC and necropsy at the end of the study 5-8 months later. One monkey appeared to have been reinfected with T. trichiura after being negative by FEC at 3 months post-treatment. Four AGMs were positive for T. trichiura at the 3 month FEC follow-up but were negative at the end of the study after one further treatment regimen. Although initially being cleared of Capillaria following treatment, three AGMs were found to be infected at the end of the study. The ivermectin and albendazole treatment regimen coupled with good husbandry practices to prevent reinfections effectively controlled nematode infections in captive AGMs. | Ross University School of Veterinary Medicine via the One Health Center for Zoonoses and Tropical Veterinary Medicine

There are limited data on the efficacy of antiparasitic treatments and husbandry methods to control nematode infections in captive populations of African green monkeys (AGMs), Chlorocebus sabaeus. In faecal egg count (FEC) tests, 10 of the 11 (91%) adult male AGMs captured from the large feral population on the island of St Kitts had evidence of nematode infections, mostly Capillaria (8/11, 73%), Trichuris trichiura (7/11, 64%) and strongylid species (7/11, 64%) specifically (hookworm and Trichostrongylus, 50/50), but also Strongyloides fuelleborni (1/11, 9%). When kept in individual cages with cleaning and feeding regimens to prevent reinfections and treated concurrently with ivermectin (300 µg/kg, given subcutaneously) and albendazole (10 mg/kg, given orally) daily for 3 days, 60% (6/10) of the AGMs were negative at a follow-up FEC at 3 months and by FEC and necropsy at the end of the study 5–8 months later. One monkey appeared to have been reinfected with T. trichiura after being negative by FEC at 3 months post-treatment. Four AGMs were positive for T. trichiura at the 3 month FEC follow-up but were negative at the end of the study after one further treatment regimen. Although initially being cleared of Capillaria following treatment, three AGMs were found to be infected at the end of the study. The ivermectin and albendazole treatment regimen coupled with good husbandry practices to prevent reinfections effectively controlled nematode infections in captive AGMs.

The reservoir host of Mokola virus (MOKV), a rabies-related lyssavirus species endemic to Africa, remains unknown. Only sporadic cases of MOKV have been reported since its first discovery in the late 1960s, which subsequently gave rise to various reservoir host hypotheses. One particular hypothesis focusing on non-volant small mammals (e.g. shrews, sengis and rodents) is buttressed by previous MOKV isolations from shrews (Crocidura sp.) and a single rodent (Lophuromys sikapusi). Although these cases were only once-off detections, it provided evidence of the first known lyssavirus species has an association with non-volant small mammals. To investigate further, retrospective surveillance was conducted in 575 small mammals collected from South Africa. Nucleic acid surveillance using a pan-lyssavirus quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) assay of 329 brain samples did not detect any lyssavirus ribonucleic acid (RNA). Serological surveillance using a micro-neutralisation test of 246 serum samples identified 36 serum samples that were positive for the presence of MOKV neutralising antibodies (VNAs). These serum samples were all collected from Gerbilliscus leucogaster (Bushveld gerbils) rodents from Meletse in Limpopo province (South Africa). Mokola virus infections in Limpopo province have never been reported before, and the high MOKV seropositivity of 87.80% in these gerbils may indicate a potential rodent reservoir.

The reservoir host of Mokola virus (MOKV), a rabies-related lyssavirus species endemic to Africa, remains unknown. Only sporadic cases of MOKV have been reported since its first discovery in the late 1960s, which subsequently gave rise to various reservoir host hypotheses. One particular hypothesis focusing on non-volant small mammals (e.g. shrews, sengis and rodents) is buttressed by previous MOKV isolations from shrews (Crocidura sp.) and a single rodent (Lophuromys sikapusi). Although these cases were only once-off detections, it provided evidence of the first known lyssavirus species has an association with non-volant small mammals. To investigate further, retrospective surveillance was conducted in 575 small mammals collected from South Africa. Nucleic acid surveillance using a pan-lyssavirus quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) assay of 329 brain samples did not detect any lyssavirus ribonucleic acid (RNA). Serological surveillance using a micro-neutralisation test of 246 serum samples identified 36 serum samples that were positive for the presence of MOKV neutralising antibodies (VNAs). These serum samples were all collected from Gerbilliscus leucogaster (Bushveld gerbils) rodents from Meletse in Limpopo province (South Africa). Mokola virus infections in Limpopo province have never been reported before, and the high MOKV seropositivity of 87.80% in these gerbils may indicate a potential rodent reservoir.

Staphylococcus species colonises humans and animals and is a major food contaminant with public health significance. Here, we assessed the occurrence of methicillin-resistant staphylococci (MRS) in the pig-production chain in Ibadan, Nigeria. Nares of 120 pigs and 10 farmers were sampled with sterile swabs whilst 54 pork samples were collected from a retail slaughterhouse. Staphylococcus species were isolated using enrichment, cefoxitin–aztreonam selective broth and Mannitol salt agar. Isolates were tested for susceptibility to cefoxitin (30 μg), oxacillin (1 μg) and vancomycin (30 μg). Methicillin-resistant staphylococci isolates were characterised using conventional biochemical tests. From 184 samples, 364 staphylococcal isolates were obtained. Amongst the 54 pork samples, 44.0% were contaminated with Staphylococcus species. Overall, 9 (2.5%) MRS were obtained and presumptively identified as Staphylococcus xylosus (n = 3), Staphylococcus sciuri (n = 3), Staphylococcus warneri (n = 2) and Staphylococcus cohnii (n = 1). There was no relationship between the prevalence of MRS between pigs and pig handlers in the farms, but Farm 2 had the highest frequency of 66.7% (p 0.05). Piglets had the highest prevalence of 66.7% (p 0.05) whilst MRS was absent in workers and pork samples. This study raises concerns about the cross-contamination of staphylococci in the food chain. Constant surveillance is imperative to ensure food safety.

Staphylococcus species colonises humans and animals and is a major food contaminant with public health significance. Here, we assessed the occurrence of methicillin-resistant staphylococci (MRS) in the pig-production chain in Ibadan, Nigeria. Nares of 120 pigs and 10 farmers were sampled with sterile swabs whilst 54 pork samples were collected from a retail slaughterhouse. Staphylococcus species were isolated using enrichment, cefoxitin–aztreonam selective broth and Mannitol salt agar. Isolates were tested for susceptibility to cefoxitin (30 μg), oxacillin (1 μg) and vancomycin (30 μg). Methicillin-resistant staphylococci isolates were characterised using conventional biochemical tests. From 184 samples, 364 staphylococcal isolates were obtained. Amongst the 54 pork samples, 44.0% were contaminated with Staphylococcus species. Overall, 9 (2.5%) MRS were obtained and presumptively identified as Staphylococcus xylosus (n = 3), Staphylococcus sciuri (n = 3), Staphylococcus warneri (n = 2) and Staphylococcus cohnii (n = 1). There was no relationship between the prevalence of MRS between pigs and pig handlers in the farms, but Farm 2 had the highest frequency of 66.7% (p 0.05). Piglets had the highest prevalence of 66.7% (p 0.05) whilst MRS was absent in workers and pork samples. This study raises concerns about the cross-contamination of staphylococci in the food chain. Constant surveillance is imperative to ensure food safety.

Human coronaviruses are known respiratory pathogens associated with a range of respiratory illnesses, and there are considerable morbidity and hospitalisation amongst immune-compromised individuals of all age groups. The emergence of a highly pathogenic human coronavirus in China in 2019 has confirmed the long-held opinion that these viruses are important emerging and re-emerging pathogens. In this review article, we trace the discovery and emergence of coronaviruses (CoVs) over time since they were first reported. The review article will enrich our understanding on the host range, diversity and evolution, transmission of human CoVs and the threat posed by these viruses circulating in animal populations but overtime have spilled over to humans because of the increased proximity between humans and animals.

Human coronaviruses are known respiratory pathogens associated with a range of respiratory illnesses, and there are considerable morbidity and hospitalisation amongst immune-compromised individuals of all age groups. The emergence of a highly pathogenic human coronavirus in China in 2019 has confirmed the long-held opinion that these viruses are important emerging and re-emerging pathogens. In this review article, we trace the discovery and emergence of coronaviruses (CoVs) over time since they were first reported. The review article will enrich our understanding on the host range, diversity and evolution, transmission of human CoVs and the threat posed by these viruses circulating in animal populations but overtime have spilled over to humans because of the increased proximity between humans and animals.

Objective: Present research aims to isolate, identify, and determine the virulence of the Streptococcus agalactiae (group B Streptococcus; GBS), isolated from popped eye disease affected Tilapia and Vietnamese Koi (V. Koi) fishes.  Materials and Methods: A total of 330 fish samples were collected, of which Tilapia (n = 180) and V. Koi (n = 150), were collected from 35 affected ponds of four selected districts of Bangladesh. Isolation of the bacterium was done using different culture media (Nutrient broth, Plate count agar, Tryptic Soy Agar, and Blood agar), and identification by using various biochemical tests (con­ventional and using API 20 Strep kit) and polymerase chain reaction (PCR) using primers against 16S rRNA gene of S. agalactiae. Antibiotic susceptibility of the bacteria was performed using seven different antibiotics disc (Tetracycline, Oxytetracycline, Chlortetracycline, Streptomycin, Ciprofloxacin, Gentamicin, and Neomycin). Virulence of the isolated S. agalactiae was determined by infecting healthy Tilapia and V. Koi fishes through experimental infection.  Results: Isolated bacteria were found Gram-positive paired and chained cocci, β-hemolytic and non-motile. Findings of biochemical and serological tests indicate that the isolated bacterium belongs to Group B Streptococcus of Lancefield classification. PCR result also confirmed that the bacteria were S. agalactiae. The bacterial isolates possessed resistance property against all the seven antibiotics used in this study. The isolated GBS was found highly virulent and showed 80%–90% mortality for Tilapia and V. Koi fishes in experimental infection within 1–6 days of post-infection.  Conclusion: From the findings of this study, it may be concluded that isolated GBS from the Tilapia and V. Koi fishes were highly virulent and possessed multidrug-resistance properties. J. Adv. Vet. Anim. Res., 8(1): 14-23, Mar 2021 http://doi.org/10.5455/javar.2021.h480

Objective: Present research aims to isolate, identify, and determine the virulence of the Streptococcus agalactiae (group B Streptococcus; GBS), isolated from popped eye disease affected Tilapia and Vietnamese Koi (V. Koi) fishes. Materials and Methods: A total of 330 fish samples were collected, of which Tilapia (n = 180) and V. Koi (n = 150), were collected from 35 affected ponds of four selected districts of Bangladesh. Isolation of the bacterium was done using different culture media (Nutrient broth, Plate count agar, Tryptic Soy Agar, and Blood agar), and identification by using various biochemical tests (con¬ventional and using API 20 Strep kit) and polymerase chain reaction (PCR) using primers against 16S rRNA gene of S. agalactiae. Antibiotic susceptibility of the bacteria was performed using seven different antibiotics disc (Tetracycline, Oxytetracycline, Chlortetracycline, Streptomycin, Ciprofloxacin, Gentamicin, and Neomycin). Virulence of the isolated S. agalactiae was determined by infecting healthy Tilapia and V. Koi fishes through experimental infection. Results: Isolated bacteria were found Gram-positive paired and chained cocci, β-hemolytic and non-motile. Findings of biochemical and serological tests indicate that the isolated bacterium belongs to Group B Streptococcus of Lancefield classification. PCR result also confirmed that the bacteria were S. agalactiae. The bacterial isolates possessed resistance property against all the seven antibiotics used in this study. The isolated GBS was found highly virulent and showed 80%90% mortality for Tilapia and V. Koi fishes in experimental infection within 16 days of post-infection. Conclusion: From the findings of this study, it may be concluded that isolated GBS from the Tilapia and V. Koi fishes were highly virulent and possessed multidrug-resistance properties. [J Adv Vet Anim Res 2021; 8(1.000): 14-23]