Reta Duguma

Seroepidemiology of Toxoplasma gondii infection in free-range chickens ( Gallus domesticus ) of Central Ethiopia

We performed a seroepidemiological study of Toxoplasma gondii infection in free-range chickens from October 2012 to May 2013. We used cross-sectional two-stage cluster sampling to collect blood samples from wing veins of 601 chickens from central Ethiopia. T. gondii-specific antibodies were assayed by modified agglutination test (MAT). We collected information about risk factors by questionnaire and used univariable and multivariable logistic regression to assess risk factors. An overall seroprevalence of 30·5% [95% confidence interval (CI) 26·27-34·14] and 54·2% (95% CI 47·06-61·36) was found at animal- and flock-level, respectively. The MAT end titre of seropositive chickens (n = 183) were 1 : 60 in 46, 1 : 180 in 28, 1 : 540 in 29, ⩾1 : 1620 in 48, 1 : 6000 in 22, 1 : 18,000 in five, 1 : 54,000 in one, and ⩾1 : 162,000 in four. Animal-level risk factors identified using multivariable logistic regression model were: midland altitude [odds ratio (OR) 2·53, 95% CI 1·12-5·72], cross and exotic breeds (OR 3·17, 95% CI 1·39-7·23), increased age of chickens (OR 2·32, 95% CI 1·19-4·49), extensive management (OR 6·92, 95% CI 1·34-35·86) and the presence of cats (OR 2·08, 95% CI 1·20-3·61). Similarly, flock-level risk factors were midland altitude (OR 3·62, 95% CI 1·31-9·99) and the presence of cats (OR 1·19-4·94). The knowledge of the local people about the health risk of cats to humans and animals is poor. Housing and management of cats and chickens are also poor. The widespread presence of T. gondii infection in free-range chickens of Central Ethiopia provides suggestive evidence for the high level of contamination of the living environment of people with T. gondii oocysts. Meat from free-range chickens might be an important source of infection for humans. Altitude, breed, age, management and presence of cats are independent predictors of seropositivity. Education of farmers about toxoplasmosis and further studies to elucidate the burden of toxoplasmosis in animals and humans warrants consideration.

Identification and Antimicrobial Susceptibility Profile of Salmonella Isolated from Selected Dairy Farms, Abattoir and Humans at Asella Town, Ethiopia

Salmonella is one of the most common causes of food-borne diarrheal disease in human as well as animals. It is leading causes of acute gastroenteritis when ingested in contaminated foods, including meat and dairy products. Moreover, the emergence of multiple-resistant (MDR) isolates is increasing in human and veterinary medicines. Therefore, this cross-sectional study aims at isolation, identification and antibiogram of Salmonella from selected dairy cattle farms, abattoir and in contact humans in both dairy farms and abattoir of Asella, Ethiopia. We collected 185 samples from abattoir (n=94) and dairy farms (n=91), which were isolated and identified according to ISO-6579, 2002. The overall proportion of Salmonella was 6.5% (12/185) (dairy farms n=4, 4.4% and abattoir n=8, 8.5%). Antibiogram of isolated Salmonella was also evaluated against ten commonly used antibiotics in both humans and veterinary medicines to treat salmonellosis by using the Kibry Bauer disk diffusion method. All isolates (100%, n=12) were susceptible to ciprofloxacin and gentamycin followed by 91.7%, 75%, 66.7%, 58.3 and 50% of the isolates were susceptible to sulfamethoxazole-trimethoprim, chloramphenicol, kanamycin, nalidixic acid and streptomycin, respectively. However, cefoxitin showed the highest resistance (66.7%) followed by ampicillin and amoxicillin (58.3% each). Moreover, 50% of the isolates were resistant to two or more of the tested antimicrobial agents. The highest MDR was seen on polled hand swabs from abattoir, resistance to eight antimicrobials (80%, n=8/10) with the combination of cefoxitin, ampicillin, amoxicillin and streptomycin being more frequent. High proportion of Salmonella was isolated from abattoir sample than dairy farms. These isolate developed MDR to commonly prescribed antimicrobial agents in the study area. Hence, strict hygienic management in the farm and abattoir as well as rational use of antimicrobials should be practised to circumvent the further development of antimicrobial resistance.

Serological responses and biomarker evaluation in mice and pigs exposed to tsetse fly bites

Background Tsetse flies are obligate blood-feeding insects that transmit African trypanosomes responsible for human sleeping sickness and nagana in livestock. The tsetse salivary proteome contains a highly immunogenic family of the endonuclease-like Tsal proteins. In this study, a recombinant version of Tsal1 (rTsal1) was evaluated in an indirect ELISA to quantify the contact with total Glossina morsitans morsitans saliva, and thus the tsetse fly bite exposure. Methodology/Principal Findings Mice and pigs were experimentally exposed to different G. m. morsitans exposure regimens, followed by a long-term follow-up of the specific antibody responses against total tsetse fly saliva and rTsal1. In mice, a single tsetse fly bite was sufficient to induce detectable IgG antibody responses with an estimated half-life of 36–40 days. Specific antibody responses could be detected for more than a year after initial exposure, and a single bite was sufficient to boost anti-saliva immunity. Also, plasmas collected from tsetse-exposed pigs displayed increased anti-rTsal1 and anti-saliva IgG levels that correlated with the exposure intensity. A strong correlation between the detection of anti-rTsal1 and anti-saliva responses was recorded. The ELISA test performance and intra-laboratory repeatability was adequate in the two tested animal models. Cross-reactivity of the mouse IgGs induced by exposure to different Glossina species (G. m. morsitans, G. pallidipes, G. palpalis gambiensis and G. fuscipes) and other hematophagous insects (Stomoxys calcitrans and Tabanus yao) was evaluated. Conclusion This study illustrates the potential use of rTsal1 from G. m. morsitans as a sensitive biomarker of exposure to a broad range of Glossina species. We propose that the detection of anti-rTsal1 IgGs could be a promising serological indicator of tsetse fly presence that will be a valuable tool to monitor the impact of tsetse control efforts on the African continent.

Staphylococcus: Isolation, Identification and Antimicrobial Resistancein Dairy Cattle Farms, Municipal Abattoir and Personnel in and AroundAsella, Ethiopia

A cross sectional study was conducted between February, 2014 and April, 2014 to isolate and identify Staphylococcus from dairy cattle farms and municipal abattoir; and to evaluate antimicrobial sensitivity for isolates in and around Asella, Ethiopia. An over all of 181 samples were collected and processed from nine dairy cattle farms (87) and seven municipal abattoir visits (94). Accordingly, 42 (23.2%) udder milk, 9 (5.0%) tank milk, 9 (5.0%) polled bucket swab, 9 (5.0%) tank swab, 9 (5.0%) polled hand swab, 9 (5.0%) polled nasal swab, from dairy cattle farms; and 66 (36.5%) meat swab, 7 (3.9%) polled knife swab, 7 (3.9%) polled slaughter line swab, 7 (3.9%) polled hand swab and 7 (3.9%) polled nasal swab from municipal abattoir visits were collected. The result showed the overall proportion of Staphylococcus was 89 (49.2%). Staphylococcal species were more predominant in abattoir 50/94 (53.2%) than farms 39/87 (44.8%), but there was no significant difference between them because p>0.05 at 95% confidence interval. Also high proportion of Staphylococcus was isolated from polled farm nasal swab 8/9 (88.9%), but this difference between sample type and the presence of Staphylococcus is not significant, because p-value (0.303) is greater than 0.05 at 0.05 level. Up on isolation and identification 35 (19.3%), 6 (3.3%), 24 (13.3%), 24 (13.3%) were S. aureus, S. intermedius, S. hyicus and Coagulase Negative Staphylococci (CNS), respectively. From total positive samples, 55 isolates were tested for antimicrobial susceptibility to different 15 antimicrobial discs. The comparative efficacies of antimicrobials used indicates Gentamycin, Kanamycin, Chloramphenicol, Ciprofloxacillin, and Sulphamethoxazole trimethoprim, were the most effective antibiotics where by 94.5%, 89.1%, 81.8%, 81.8%, and 81.8% respectively. Good hygienic practices should be followed both in dairy cattle farms and municipal abattoir including working personnel and equipment’s used; and antimicrobials susceptibility test should be carried out at regular intervals to find out the development of resistance against the most commonly applied antibiotics.

Majority of T. gondii seropositive chickens (Gallus domesticus) in Central Ethiopia carries the infective parasite.

BackgroundThe prevalence of Toxoplasma gondii in free range chickens is a good indicator of the prevalence of T. gondii oocysts in the environment. The aim of this study was to isolate T. gondii parasites from heart and brain of seropositive free range (FR) chickens.FindingsIsolation of T. gondii from pooled heart and brain of 41 direct agglutination test (DAT) positive (≥1:40) free range chickens (Gallus domesticus) was carried out by bioassay in mice. T. gondii specific antibodies in mice were assayed by DAT and microscopy was employed for detection and enumeration of brain tissue cysts. Overall, bioassay was positive in 29 (70.7%) chicken samples. T. gondii tissue cysts were isolated from 59% (24/41) of bioassayed chickens: from 2 of 7 chickens with a titer of 1: ≤ 60, 2 of 5 with titer 1: 180, 6 of 8 with titer 1: 540, 10 of 15 with titer 1: 1620, 1 of 2 with titer 1: 6000, 2 of 3 with titer 1:18000, 1 of 1 with titer 1:54000. None of the isolates was pathogenic for mice. Tissue cysts were detected from 61% of seropositive mice (DAT ≥ 1:40). Generally, tissue cyst counts per brain of mouse were low (mean: 132.7 ± 84.4; range: 47-352).ConclusionsMajority of T. gondii seropositive chickens (Gallus domesticus) in Central. Ethiopia carries the infective parasite. Tissues from the free range chicken might be a source infection for animals and humans.