Brucellosis surveillance and control in Zimbabwe: bacteriological and serological investigation in dairy herds

Brucellosis in dairy cattle is endemic in Zimbabwe. The prevalence continues to be monitored intensively. Only milk and serum samples are routinely screened. Attempts to culture Brucella spp. from clinical specimens are seldom made. Consequently, incidence of various Brucella spp. within Zimbabwe is virtually unknown, despite the high serepositivity reported. This information is paramount in understanding the transmission cycle and is also significant to public health; particularly as B. melitensis infects humans more often than do the other brucellae. This paper describes the results of bacteriological and serological investigations of brucellosis in a dairy farm near Bulawayo. The said farm was selected for the present pilot study because of the high incidence of reported abortion. The milk ring test was employed to test the bulk pooled milk samples once a month for 14 months. The test was recorded highly positive on all 14 occasions. To locate reactors, milk samples from 36 individual cows were similarly tested. Of these, 21 (almost 59 %) were found to be reacting positively. One hundred and seventy-seven animals were marked for serotesting. Of these, 40 (approximately 25 %) showed quite high serum titres (> 1 :360) in both the STT and the Rosebengal test. The farmer was advised to have all abortions fully investigated. However, all the clinical material from cases of abortion, except one, were received in an advanced state of putrefaction. From this, Brucella was isolated on culture from stomach contents and cotyledons. The isolates from both the sites were characterized in detail, employing dye inhibition, phagetyping; the oxidative metabolic test and agglutination with monospecific sera. Both the isolates belonged to B. abortus biovar I, which was confirmed by the Central Veterinary Research Laboratory, Weybridge. The significance of isolation and the need to intensify similar studies have been discussed.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Relationship between burden of infection in ungulate populations and wildlife/livestock interfaces

In southern African transfrontier conservation areas (TFCAs), people, livestock and wildlife share space and resources in semi-arid landscapes. One consequence of the coexistence of wild and domestic herbivores is the risk of pathogen transmission. This risk threatens local livelihoods relying on animal production, public health in the case of zoonoses, national economies in the context of transboundary animal diseases, and the success of integrated conservation and development initiatives. The level of interaction between sympatric wild and domestic hosts, defining different wildlife/livestock interfaces, characterizes opportunities of pathogen transmission between host populations. Exploring the relationship between infection burden and different types of wildlife/ domestic interfaces is therefore necessary to manage the sanitary risk in animal populations through control options adapted to these multi-host systems. Here, we assessed the infection burdens of sympatric domestic cattle (Bos taurus/Bos indicus) and African buffalo (Syncerus caffer) at an unfenced interface and compared the infection burdens of cattle populations at different wildlife/ livestock interfaces in the Great Limpopo TFCA. Patterns of infection in ungulate populations varied between wild and domestic hosts and between cattle populations at different wildlife/livestock interfaces. Foot-and-mouth disease, Rift Valley fever and theileriosis infections were detected in buffalo and cattle at unfenced interfaces; bovine tuberculosis was only present in buffalo; and brucellosis and lumpy skin disease only in cattle. At unfenced interfaces, cattle populations presented significantly higher Theileria parva and brucellosis prevalence. We hypothesize that cattle populations at wildlife/livestock interfaces face an increased risk of infection compared to those isolated from wildlife, and that the type of interface could influence the diversity and quantity of pathogens shared. Additional host behavioural and molecular epidemiological studies need to be conducted to support this hypothesis. If it is confirmed, the management of wildlife/livestock interfaces will need to be considered through the prism of livestock and public health.The European PARSEL project (No. Food 2007 137-950) and by the Ministère Français des Affaires Etrangères through the French Embassy in Zimbabwe (RP-PCP grants 2008 and 2009).http://journals.cambridge.org/action/displayJournal?jid=HYGam201

Tick infestation, and udder and teat damage in selected cattle herds of Matabeleland South, Zimbabwe

A cross-sectional survey was conducted to determine tick infestation, and udder and teat damage in 286 lactating cows and heifers at six properties in the smallholder and commercial sectors in Gwanda district of Matabeleland South Province, Zimbabwe. Eight tick species were identified: Amblyomma hebraeum, Hyalomma truncatum, Hyalomma marginatum rufipes, Rhipicephalus evertsi evertsi, Rhipicephalus (Boophilus) decoloratus, Rhipicephalus appendiculatus, Rhipicephalus zambeziensis and Rhipicephalus simus. Overall, 81.5 % of the cattle were tick infested; prevalence of tick-infested cattle was significantly higher on communal land (93.8 %) and recently claimed land (85.1 %) than on commercial farms. The mean tick load on infested cattle on communal land was significantly higher than in the other two sectors. Although 53 % of the sampled cattle had some degree of udder and teat damage, very few farmers (2.6 %) treated their cattle for these conditions. Udder damage was ca. two times and three times, respectively, more likely to occur in cattle on communal land compared to cattle on recently claimed land and commercial farms. The occurrence of R. appendiculatus and R. zambeziensis indicate that the cattle population in the study area is at high risk of a theileriosis outbreak, a tick-borne disease that has not been reported from this area

Antibiotic Susceptibility of Mastitogenic Bacteria Isolated From Clinical Mastitis Cows in Midlands Province, Zimbabwe

Mastitis is a global challenge for the dairy industry and mastitogenic bacteria play a critical role among other causes. Many mastitogenic bacteria are becoming resistant to single or combination antibiotic therapy, making mastitis cases difficult to cure. Nevertheless, there is insufficient evidence on the occurrence and antibiotic resistance patterns of mastitogenic bacteria in commercial dairy and communal farms in the Midland Province of Zimbabwe that might support a holistic approach to mastitis mitigation. A cross-sectional study aimed to isolate and evaluate the antibiotic susceptibility patterns of mastitogenic bacteria from cattle with clinical mastitis was conducted. A total of 164 milk samples were analyzed, of which 36.6% (60) samples were collected from commercial farmers, and 63.4% (104) came from communal farmers. The samples were cultured on standard media and sensitivity patterns of the identified bacteria were tested against 14 antibiotics using the Kirby-Bauer disc diffusion method. All milk samples from communal farms were positive for mastitogenic bacteria compared to 88% (53) of mastitogenic positive milk samples from commercial farms. The most common microorganisms from all the 157-mastitogenic positive milk samples were Staphylococcus aureus (37.5%) and Escherichia coli (23.3%). The highest resistance was observed against Penicillin, Erythromycin, Ampicillin, and Lincomycin, whereas most isolates were susceptible to Sulphamethoxazole, gentamycin, neomycin, kanamycin, cloxacillin, ertapenem, ceftriaxone, Amp-Ampicillin, amikacin, vancomycin, and tetracycline. Futher research to investigate the significance of resistant mastogenic bacteria in terms of Veterinary costs, production losses and potential public health transmission of antibiotic resistant mastogenic bacteria is recommende

Prevalence and Antibiograms of Salmonella in Commercially Produced Crocodile meat in Zimbabwe

The presence of Salmonella in food products and emergence of antibiotic resistance are the major challenges facing public health policies. A total of 2749 crocodile meat samples obtained from the Central Veterinary Laboratories in Zimbabwe were screened for Salmonella specieswere collected from three Zimbabwean commercial farms between the year 2012 and 2019 for a retrospective observational study to determine the prevalence and magnitude of antibiotics resistant Salmonella species in crocodile meat. The isolation of Salmonella was in accordance with the ISO 6579:2002 and the antibiotic susceptibility testing was carried out based on Clinical and Laboratory Standard Institute’s recommendations by means of the Kirby-Bauer disk diffusion method. SILAB Database was used to determine the prevalence of Salmonella species. Prevalence was stratified by year and farms. Twenty Salmonella isolates were identified using biochemical tests, and 15 were confirmed by polymerase chain reaction (PCR). Antimicrobial susceptibility profiles of the confirmed Salmonella isolates were examined using 14 antibiotics. The overall prevalence of Salmonella species in crocodile meat samples was 0.5%. The prevalence of Salmonella species ranged from 0.04% to 0.44% in the crocodile meat samples and annual prevalence ranged from 0.01% to 1%. The highest prevalence of Salmonella (4.4%) was recorded in the year 2012. Salmonella isolates from one of the three tested farms were resistant to Erythromycin (73.33%), Ampicillin (80%), and Penicillin G (100%). Generally, Salmonella isolates displayed lower resistance to Cefepime, Ceftriaxone, Amikacin, Tetracycline, Ertapenem, Florfenicol, and Erythromycin (0-53.33%) whereas all Salmonella isolates showed susceptibility to Cefepime, Ceftriaxone, Ertapenem, and Florfenicol. Although the study indicates low prevalence of Salmonella species in crocodile meat, there is a need for strict implementation of Hazard Analysis Critical Control Point (HACCP) to reduce contamination rates in meat and its product