Haruna M. Kazeem

Characterization of field and vaccine infectious bursal disease viruses from Nigeria revealing possible virulence and regional markers in the VP2 minor hydrophilic peaks

Outbreaks of infectious bursal disease in vaccinated chicken flocks are frequent in Nigeria. For the control of infectious bursal disease, live vaccines based on foreign infectious bursal disease virus (IBDV) strains are used. The present study investigated the phylogenetic relationship between field and vaccine IBDV strains from northwestern Nigeria. Thirty field IBDV strains and three commercial vaccines strains were characterized through sequencing the VP2 hypervariable region. In addition, the complete genome segment A coding region for two vaccines and two field strains was sequenced. The deduced amino acid sequences (position 212 to 331) of IBDV strains from Nigeria and other regions of the world were aligned and possible regional and virulence markers were identified associated with VP2 minor hydrophilic peaks. Reversion to virulence of a vaccine strain with a Q to L mutation at position 253 was observed. Phylogenetic analyses revealed a unique cluster of northwest Nigerian field IBDV strains alone or related to imported characterized classical and very virulent IBDV vaccines. The results suggest that when IBDV strains spread from their region of origin to a different region they mutate alongside indigenous field strains but may retain their identity on the VP2 region.

Rabies and Dog Bites Cases in Lagos State Nigeria: A Prevalence and Retrospective Studies (2006-2011)

This study was carried out to determine the prevalence of rabies antigen in brain of dogs slaughtered for consumption and those that died in veterinary clinics as well as to obtain a 6-year retrospective data on dog bites/suspected dog rabies cases in Lagos State. Dog brain samples were collected from dog slaughter slabs and veterinary clinics (for dogs that died in clinics) across the Lagos state while data for retrospective studies (2006-2011) of dog bite/suspected rabies cases were collected from public (government owned) and private veterinary clinics across the state. Out of the 444 brain samples collected and tested for presence of rabies antigen using the direct fluorescent antibody technique (DFAT) only 7 (1.58%) were positive for the rabies antigen. A total of 196 dog bites/suspected rabies cases were encountered between January 2006 and December, 2011 in the veterinary clinics with adults been the major (55.61%) victims. Majority (96.43%) of the offending dogs were not quarantined at the time of bite and only one out of the quarantined dogs died and was confirmed positive for rabies antigen. The result of this study indicates that rabies antigen is present among dogs slaughtered in Lagos State and may pose a threat to public health. Though, available records showed that provocation of dogs was the major cause of dog bites and both children and adults fell victim of dog bites, there was a poor record keeping practice in the veterinary clinics across the state.

Dog ecology and population studies in Lagos State, Nigeria.

Dog population dynamics have a major impact upon the effectiveness of rabies control strategies. As such, understanding domestic dog ecology has been recognized as central to the design of effective rabies control programmes. This study was conducted to determine the dog ecology in Lagos State using compound dog count and street dog count in the three senatorial districts (Lagos West, East and Central) of Lagos State from February, 2011 to January, 2012. A total of 546 questionnaires were distributed for the compound dog count and all were completed and returned. Various aspects of dog ecology were determined, including size, sex, breed of the dog population, management of dogs and rabies awareness among the respondents. Out of the 546 compounds surveyed, 518 (94.87%) owned at least one dog. A total of 1,427 dogs were counted from the street counts while a total of 1,447 dogs (2.8 dogs/compound) were counted from the compound count. The dogs comprised of 583 males and 864 females, out of which 64.10% are confined. The dog vaccination coverage in the dog population surveyed was 64.10% and administered majorly (91.30%) by veterinarians. Security (60%) and pets (26%) were the major reasons for keeping dogs. Majority (88.80%) of the respondents were aware of rabies and its mode of transmission, but still believed in the use of concoctions (40.40%), herbs (19.90%) and consumption of the organ of the offending dog (11.50%) for the treatment of rabies. The findings of this study showed a male: female ratio of dog to be 1:1.5 and a dog: human ratio of 1:5.6. There was also a responsible dog ownership as majority of the respondents do confine, vaccinate and provide food for their dogs. Vaccination coverage of the total dog population was however below the 70-80% target recommended by the World Health Organization to achieve herd immunity.

Dermatophytes from skin lesions of domestic animals in Nsukka, Enugu State, Nigeria

BACKGROUND Dermatophytes are well-recognized cutaneous fungi with public health implications. In Nigeria, several studies have been carried out on dermatophytosis in humans; however, data on dermatophytes in animals are lacking. OBJECTIVES This study was conducted to determine the occurrence and species of dermatophytes in skin lesions in domestic animals in Nsukka Agricultural Zone of Enugu State, Nigeria. ANIMALS Forty-six domestic animals (dogs, goats, sheep and pigs) presented for sale in the local markets in the study area and with suspected lesions of dermatophytosis were used for the study. METHODS Plucked hairs and epidermal scales from the skin lesions of affected animals were inoculated on Sabouraud dextrose agar slants containing 0.05 mg/mL of chloramphenicol and 0.5 mg/mL of cycloheximide. Inoculated slants were incubated at room temperature (27°C) for up to 4 weeks and examined at 2-3 day intervals for fungal growth. Laboratory identification of the fungal isolates was based on their colonial, microscopic and biochemical characteristics. RESULTS Of the 46 animals with suspected lesions of dermatophytosis, six (13.0%) were positive for a dermatophyte, and the following dermatophytes were identified: Microsporum gypseum, two of 12 sheep; Microsporum audouinii, one of 16 dogs; Trichophyton mentagrophytes, one of 16 dogs and one of 12 sheep; and Trichophyton schoenleinii, one of 13 goats. CONCLUSIONS AND CLINICAL IMPORTANCE Anthropophilic dermatophytes are among the fungal agents associated with dermatophytosis in animals in Nsukka Agricultural Zone. These dermatophytes could constitute health risks to humans in contact with the animals.

Equine Dermatophytosis: A Survey of Its Occurrence and Species Distribution among Horses in Kaduna State, Nigeria

This study was designed to determine the occurrence and species distribution of dermatophyte from cutaneous skin lesions of horses in Kaduna State, Nigeria. A total of 102 skin scrapings were collected from 102 horses with skin lesions. Mycological studies were carried out using conventional techniques. Dermatophytes were isolated from 18 (17.6%) of the 102 samples collected. The 18 dermatophytes were distributed into 10 different species belonging to Microsporum (n = 5) and Trichophyton (n = 5) genera. T. verrucosum (n = 4) was the most predominant species isolated followed by M. equinum (n = 3), T. vanbreuseghemii (n = 2), M. gypseum (n = 2), and M. canis (n = 2). Others include M. fulvum (n = 2), T. mentagrophytes (n = 1), T. equinum (n = 1), T. soudanense (n = 1), and M. gallinae (n = 1). The present study reveals the occurrence of dermatophytes in cutaneous skin lesions of horses in Kaduna State, Nigeria. In addition for the first time in this environment the anthropophilic dermatophyte T. soudanense was isolated from horses. These findings have great economic, veterinary, and public health significance as they relate to the cost of treatment and dissemination of zoonotic dermatophytes.

Severe generalized skin lesions due to mixed infection with Sporothrix schenkii and Dermatophilus congolensis in a bull from Jos, Nigeria.

Sporothrix schenkii and Dermatophilus congolensis were isolated from a bull with severe generalized skin lesions. The lesions were thick, crusty and scabby on the dorsal part while few scabby and several nodular lesions were seen on the lower limbs especially the thighs. Scab samples and exudates from the nodules were aseptically collected and processed for bacteriology and mycology. Gram stained smears revealed Gram-positive, filamentous organism that had longitudinal and transverse septa suggestive of D. congolensis. Colonies on 5% defibrinated sheep blood agar were small, rough, grayish-white, β-hemolytic and adherent to the medium. It was catalase positive, urease positive and fermented glucose and maltose but not sucrose, lactose, mannitol, sorbitol and xylose. Colonies on Sabourauds dextrose agar were small, round, white and opaque, delicate and smooth. It liquefied gelatin and fermented glucose and sucrose but not galactose, menite, and glycerin. The isolate was Gram-positive, cigar-shaped and yeast-like suggestive of S. schenkii. Dermatophilosis is common in domesticated ruminants while sporotrichosis is very rare in cattle. This may be the first report of bovine sporotrichosis from Africa.

Complete Genome Sequence of a Street Rabies Virus Isolated from a Dog in Nigeria

ABSTRACT A canine rabies virus (RABV) was isolated from a trade dog in Nigeria. Its entire genome was sequenced and found to be closely related to canine RABVs circulating in Africa. Sequence comparison indicates that the virus is closely related to the Africa 2 RABV lineage. The virus is now termed DRV-NG11.

Serosurvey of peste des petits ruminants virus in small ruminants from different agro-ecological zones of Nigeria

Peste des petits ruminants, caused by the peste des petits ruminants virus (PPRV), is a highly contagious and economically important transboundary viral disease of domestic and wild small ruminants and a major hindrance to small-ruminant production in Nigeria. The seroprevalence and distribution of PPRV antibodies in small ruminants in rural households, farms, live animal markets and slaughter slabs across the six different agro-ecological zones of Nigeria were determined. A total of 4548 serum samples from 3489 goats and 1059 sheep were collected in 12 states. A PPRV competitive enzyme-linked immunosorbent assay was used to test the samples and the data analysed with R statistical software version 3.0.1. The study animals included all ages and both sexes. The overall prevalence estimate of sera positive for PPRV antibodies was 23.16% (n = 1018 positive samples per 4548 total samples, 95% confidence interval: 21.79% – 24.57%). There were significant differences in the seroprevalence between the states (p = 0.001). Taraba State had the highest seroprevalence of 29.51%, whilst the lowest seroprevalence of 14.52% was observed in Cross River State. There were no significant differences in the PPRV seroprevalence between male and female animals (p = 0.571), age (p = 0.323) and between species (p = 0.639). These data indicate the current seroprevalence to PPRV in the small-ruminant population in Nigeria.

A Novel Report on the Prevalence of Enterohaemorrhagic ( Escherichia Coli ) non-O157 Isolated from Cattle in Kaduna State , Nigeria

This study was carried out to investigate the presence of enterohaemorrhagic Escherichia coli (EHEC) of cattle that may pose a risk to human beings. Two hundred and forty (240) faecal samples were obtained from 8 randomly selected commercial cattle farms in Kaduna state, Nigeria. E. coli colonies from 76 (31.2 %) faecal samples were confirmed by Gram staining reactions and biochemically using indole, methyl red, Voges Proskauer and citrate (IMViC), triple sugar iron and motility tests respectively. Characterization of the isolates revealed three heterogeneous serogroups (O111, O118 and O126) from apparently healthy cattle, while no E. coli serogroup was isolated from diarrhoeic cattle. The prevalence of non-O157 isolates was 4.5 %. Association between the serogroups and source of samples (farms) was significant (P<0.05). The O126 serogroup isolated from apparently healthy cattle occurred more frequently, followed by O118 and O111 respectively. Although it is not known whether the presence of EHEC subgroups in apparently healthy cattle in the study areas may pose a health threat, it is safe to assume that the human population in these areas, including cattle rearers and veterinarians, is at risk of exposure to the EHEC subgroups reported in the study. Data from the study possibly suggest cattle as important source of enterohaemorrhagic E. coli in Kaduna State, Nigeria.

Heat induced epitope retrieval for rabies virus detection by direct fluorescent antibody test in formalin-fixed dog brain tissues

There is a great need for a chemical method of tissue preservation that would allow sample storage for extended periods at room temperature. This study aimed at retrieving and detecting rabies virus antigen by direct fluorescent antibody test (DFAT) in formalin-fixed dog brain tissues. Forty fresh dog brain specimens were collected as paired samples from rabies suspected cases that were received for postmortem detection of rabies in the Central Diagnostic Laboratory, National Veterinary Research Institute, Vom. One portion of each paired sample was prepared for fresh fluorescent antibody testing and the other portion was prepared for epitope retrieval and florescent antibody testing following fixation in 10% neutral buffered formalin. DFAT on formalin-fixed tissue exhibited a sensitivity of 100% in comparison to DFAT on fresh-tissue. No false positive result was obtained in formalin-fixed DFAT procedure, demonstrating 100% specificity. There was no apparent difference in the intensity of fluorescence in DFAT on fresh sample and formalin-fixed DFAT following heat induced epitope retrieval (concordance = 98%; 95% C.I. 0.9660 to 0.9903). The strength of agreement between DFAT on formalin-fixed and DFAT on fresh tissue was very good (Cohen’s kappa coefficient value= 1.000; 95% C.I. 1.000-1.000). This study provides new information on the retrieval of rabies antigen by heat induced epitope retrieval for DFAT on formalinized tissues. Formalin could therefore, be used henceforth to fix tissues of rabies suspected cases for routine diagnosis, transportation or archival purposes. The heat induced epitope retrieval can be routinely used to retrieve rabies virus antigen for DFAT in cases where only formalin-fixed tissues are available or when preservation by freezing is difficult.