Subclinical mastitis in pastoralist dairy camel herds in Isiolo, Kenya: Prevalence, risk factors, and antimicrobial susceptibility.

Mastitis is an important constraint to milk production in pastoralist camel (Camelus dromedarius) herds in Kenya. The objective of this study was to investigate the prevalence, risk factors, and bacterial panorama of subclinical mastitis (SCM) in pastoralist camel herds in Isiolo County, Kenya. Furthermore, antimicrobial susceptibility in udder pathogens was studied. A cross-sectional sample of 206 camels from 20 milking herds was screened using the California Mastitis Test (CMT), and quarter milk was subjected to bacterial culturing. Isolates were confirmed using MALDI-TOF mass spectrometry analysis, and antimicrobial susceptibility was determined using the broth microdilution method. Interviews focusing on herd management were conducted with camel owners. Subclinical mastitis, defined as a CMT score ≥ 3 (scale 1 to 5) and absence of clinical symptoms in the udder, were present in all visited herds. On the individual level, 46% of the camels had at least 1 quarter affected with SCM, and on the quarter level the prevalence was 26%. Intramammary infections (IMI) were common; out of 798 quarter milk samples, 33% yielded conclusive bacterial growth. The sensitivity and specificity of CMT for correctly identifying quarters with IMI were 82% and 92%, respectively. The most prevalent pathogen was Streptococcus agalactiae (72% of IMI-positive quarters), followed by non-aureus staphylococci (19%) and Staphylococcus aureus (13%). Antimicrobial susceptibility testing revealed that only a low proportion (4.9%) of Strep. agalactiae isolates was sensitive to tetracycline. For Staph. aureus, 59.1% of isolates exhibited sensitivity to penicillin. Skin lesions on the teats or udder were a risk factor for SCM. Increased age, parity, and stage of lactation were associated with increased risk of both SCM and IMI. Older camels with a blind teat or a previous history of mastitis were more likely to be infected with Strep. agalactiae. Hygiene routines for milking were largely absent in the observed herds, and knowledge of adequate milk handling was limited. The poor udder health is likely to depend on multiple factors, most prominently the within-herd maintenance of contagious udder pathogens, in combination with difficult sanitary conditions and lack of awareness among camel keepers. This study showed that in pastoralist camel herds around Isiolo town, SCM and IMI specifically caused by Strep. agalactiae are common udder health problems and are associated with increasing age, parity, and stage of lactation, and skin lesions on the teats and udder. Resistance to tetracycline in Strep. agalactiae was common. Control strategies specifically targeting SCM and adapted to pastorally managed camel herds need to be developed to reduce disease, combat antimicrobial resistance, and improve the livelihoods of pastoralists.

Indigenous knowledge of pastoralists on respiratory diseases of camels in northern Kenya.

The camel disease terminology of pastoralists in northern Kenya differentiates between two respiratory disease complexes of camels. Participatory epidemiology data were collected in 2011 in three camel keeping communities (Gabra, Garri, and Somali) and analysed to assess the validity of this differentiation. Further queries assessed recurrence of the disease in the same animal, most affected age group, relative frequency of occurrence, morbidity rates, mortality rates and response to antibiotic treatment. Based on matrix scoring the cardinal symptom nasal discharge was significantly correlated with Respiratory Disease Complex 1 (RDC1; Somali Hergeb, Gabra & Garri Furri) while cough was correlated with Respiratory Disease Complex 2 (RDC2; Somali Dhuguta, Gabra Qufa, Garri Dhugud). RDC1 appears to occur regularly every year and does not respond to antibiotic treatments while outbreaks of RDC2 are only observed at intervals of several years and treated cases do generally respond to antibiotics. While RDC1 is more severe in calves, RDC 2 is mostly associated with respiratory disease in adults. Elements of this differentiation appear to be in agreement with other authors who differentiate between camel influenza (PI3 virus) and bacterial camel pneumonia, respectively.

MERS and the dromedary camel trade between Africa and the Middle East.

Dromedary camels are the most likely source for the coronavirus that sporadically causes Middle East respiratory syndrome (MERS) in humans. Serological results from archived camel sera provide evidence for circulation of MERS coronavirus (MERS-CoV) among dromedary camels in the Greater Horn of Africa as far back as 1983 and in Saudi Arabia as far back as 1992. High seroprevalences of MERS-CoV antibodies and the high virus prevalence in Saudi Arabian dromedary camels indicate an endemicity of the virus in the Arabian Peninsula, which predates the 2012 human MERS index case. Saudi Arabian dromedary camels show significantly higher MERS-CoV carrier rates than dromedary camels imported from Africa. Two MERS-CoV lineages identified in Nigerian camels were found to be genetically distinct from those found in camels and humans in the Middle East. This supports the hypothesis that camel imports from Africa are not of significance for circulation of the virus in camel populations of the Arabian Peninsula.

Isospora orlovi infection in suckling dromedary camel calves (Camelus dromedarius) in Kenya.

Outbreaks of isosporosis in young suckling dromedary camel calves (Camelus dromedarius) in Dubai, UAE and in Kenya were recently described. In the former outbreak the pathogen was shown to be Isospora orlovi by morphological features and was later characterized molecularly. In the present study, we have made a longitudinal investigation of 159 suckling dromedary calves < or =12 weeks of age belonging to 8 ranched camel herds (M1) in Northern Kenya. The study was carried out during 18 months. In three of the herds frequent samples were taken irregularly every 1-6 weeks. All calves < or =12 weeks of age present in the respective herds were sampled during the visits. In addition, 91 calves of the same age group but belonging to 42 pastoral herds (M2) in Northern Kenya were point sampled at convenience. Faecal samples from each calf were taken and the faeces were investigated for coccidia. Samples found with coccidian oocysts were suspended in a 2% potassium dichromate solution. Isospora sp. was identified and samples with relatively high numbers of Isospora sp. were analysed molecularly. The SSU rRNA gene and internal transcribed spacer 1 (ITS1) were amplified with primers complementary to conserved regions of the SSU rRNA gene in eukaryotes as well as a conserved part of the 5.8S rRNA gene of Eimeria. A relatively high number of the calves exhibited diarrhoea, 30.2% and 41.8% in the M1 and M2 herds, respectively. Isospora sp. was only found in diarrhoeic calves or in calves convalescent from recent scouring periods. No calf >8 weeks of age was found to be excreting Isospora sp. The parasite was only found in calves < or =4 weeks of age in the M1 herds and in the M2 herds in calves <8 weeks of age. Of the M1 and M2 calves exhibiting diarrhoea, 20.8% and 26.3% excreted Isospora sp., respectively. Morphologically the Isospora sp. was similar to I. orlovi and sequence analysis of the SSU rRNA gene from four Kenyan isolates (unfortunately only from the pastoral herds, M2) and ITS 1 segments from three of the isolates from Kenya and one from Dubai, confirmed that the Isospora isolates belonged to the species I. orlovi, and that the sequences were similar to the Dubai isolates.

Lancefield group B and C streptococci in East African camels (Camelus dromedarius).

Seventeen Lancefield group C streptococci (13 Streptococcus equi zooepidemicus and four Streptococcus dysgalactiae equisimilis) and 185 Lancefield group B streptococci (Streptococcus agalactiae) were isolated from camels (Camelus dromedarius) in Kenya and Somalia; 59 of the isolates were from healthy nasopharynx, vaginal and rectal mucosa and from non-abscessed lymph nodes, and the other 143 isolates were from clinical infections of the respiratory tract, tick bite lesions, abscessed lymph nodes, abscesses and other purulent skin lesions, periarthritis and arthritis, puerperal infection and gingivitis. The role of Lancefield group B and C streptococci as commensals and common opportunistic pathogens in East African camels is described.

Identification and molecular characterization of Streptococcus equi subsp. zooepidemicus isolated from camels (Camelus dromedarius) and camel milk in Kenya and Somalia.

Seventeen Streptococcus equi subsp. zooepidemicus strains isolated from camels and camel milk in Kenya and Somalia were identified by their cultural characteristics, by biochemical and serological reactions with the help of commercial identification systems and by molecular studies using a multiplex PCR. The isolates were further characterized by a PCR-mediated detection of size polymorphisms in the 16S-23S rDNA intergenic spacer region and the virulence gene szp and by amplification of the virulence gene cne. These molecular analysis are potentially useful in identifying and characterizing S. equi subsp. zooepidemicus strains of this origin and could possibly be valuable in epidemiological investigations.

Application of the California mastitis test in intramammary Streptococcus agalactiae and Staphylococcus aureus infections of camels (Camelus dromedarius) in Kenya.

A study was conducted on 207 lactating camels in six herds in Kenya to evaluate the California mastitis test (CMT) for the detection of intramammary infections (IMIs) caused by Streptococcus agalactiae and Staphylococcus aureus and to investigate the prevalence of both the pathogens in the camel udder. IMI with S. agalactiae was found in 12% of all camels sampled. IMI with S. aureus was present in 11% of all camels sampled. The herd-level prevalence of IMI varied between 0 and 50% for S. agalactiae and between 0 and 13% for S. aureus. Longitudinal observations over 10-12 months confirmed persistent infections for both pathogens. Observations in one herd suggested that camel pox was a contributing factor in spreading and exacerbating S. agalactiae udder infections.The CMT had quarter-level sensitivities of 77 and 68% for S. agalactiae and S. aureus in camels, respectively. The CMT specificities were 91% for both the pathogens.

Update on footrot in south-west Germany.

82 Dichelobacter nodosus strains isolated from 9 footrot affected sheep flocks in south west Germany were serotyped and tested for virulence. Serovar B was present in all flocks, representing 64.4% of all isolated D. nodosus field strains. Other serovares found were type A, C, E, G and H. Virulent strains were identified in 5 flocks, while intermediate strains were isolated from all 9 flocks. All serological untypeable strains proved to be avirulent. Based on these epidemiological findings the use of currently available commercial footrot vaccines is appropriate in south west German sheep populations.

Short communication: bovine paraplegic syndrome (Mal de Aquidabàn) in Paraguay caused by C. perfringens toxovar D.

In the vicinity of the river Aquidabán in Eastern Paraguay occurred in the last years an endemic disease within cattle herds which killed thousands of heads (Mal de Aquidabán [MdA]). The disease was seen in form of an afebrile, paralytic condition characterized by muscle tremors, swaying of the hind quarters, recumbence and sudden death of the animals. Therefore it was described as "Bovine Paraplegic Syndrome". Comparable symptoms in adult cattle have also being seen in Eastern and Central Venezuela. After we found in the peritoneal fluid of 2 animals, which died under typical symptoms, toxins of C. perfringens toxovar D, we started to investigate the occurrence of C. perfringens in the feces of clinical healthy animals on farms, where MdA was diagnosed before. There we found 73% of the isolated strains belonging to toxovar D. In herds with no case of the disease toxovar A was isolated up to 90%. The next step was the production of a vaccine (anaculture) with a high toxin producing strain of C. perfringens toxovar D. 2000 cattle were vaccinated for 3 years twice a year. None of the vaccinated animals diseased. In 2 control-herds some cases of MdA occurred. But we became quite sure that MdA was an infectious disease, when we started to vaccinate cattle of unvaccinated herds where MdA suddenly occurred. One or two animals died in the next 2 days and after this period the endemic disease was immediately stopped.

Differentiation of proteinase (minor toxin lambda) in Clostridium perfringens strains from sheep and goats in Iran.

17 Clostridium perfringens strains isolated post mortem from sheep and goats in Iran were examined by biochemical tests and by enzyme immuno assay (EIA). 7 of the C. perfringens strains belonged to type B, 8 strains were type D, one strain was type A, one strain was untypable by EIA. The isolated strains were examined for presence of Minor Toxin Lambda (proteinase) to identify the Iran subtype of C. perfringens type B. The results are compared to characteristics of Clostridium perfringens reference strains. The differentiation technique for proteinase (Minor Toxin Lambda) is discussed.

Clostridium perfringens toxins absorbed on filter paper--a simple method for sample conservation.

Clostridium perfringens type C and type D toxins were absorbed on filter paper, dried and stored at room temperature (18-20 degrees C), at 37 degrees C, at 4 degrees C and at -20 degrees C. Type specific toxin was correctly identified in the EIA for 74 days. Absorption on filter paper may offer a simple method for conservation and transport of post mortem samples from cases of suspected enterotoxaemia.

Vaccination of grasscutters with a multicomponent clostridial vaccine.

Grasscutter serum antibodies against Clostridium perfringens beta-toxin were titrated in an enzyme immunoassay. The procedure that is currently used for vaccinating domesticated grasscutters is discussed.

Characterisation of a new Pasteurella haemolytica serotype (A17).

Four strains of Pasteurella haemolytica representing a new serotype (A17) were isolated from sheep in Syria. The identity of the new serotype was established by comparison with P haemolytica type strains A1 to A16 in the indirect haemagglutination test.

Frequency of Clostridium perfringens types in Jordanian sheep.

778 fecal samples from 29 Jordanian sheep flocks were examined for the presence of Clostridium perfringens. 252 field strains were isolated and typed by the enzyme immunosorbent assay. The presence of C. perfringens types B, C and D in Jordanian sheep was confirmed. Type D was found in 55% of the flocks examined. Types B and C were each isolated from 7% of the flocks examined. The proteinase activity of isolated type B field strains was similar to that of type B reference strains. According to the results, it does not seem to be necessary to include locally isolated C. perfringens strains in the Jordanian vaccine production.

Species identification and serotyping (capsular antigen) of Pasteurella strains from sheep flocks in south Germany and in Syria.

135 Pasteurella strains were cultivated from nasal swabs of sheep as well as pneumonic lungs of dead and slaughtered sheep. The specimen originated from 41 flocks in South Germany and from 15 flocks and 60 slaughter sheep in Syria (Hama region). Serovariety A2 prevailed amongst P. haemolytica strains (6) isolated in South Germany (53 strains) and in Syria (41 strains). In addition 10 further serovarieties were identified in South Germany (next frequent were A8, A1 and A6) and 7 in Syria. Untypable strains appeared to be more frequent in Syria. Other Pasteurellae (17) represented 1/4 of isolates in Syria and 1/3 of isolates in South Germany. Species identification resulted in P. multocida ssp. multocida (25), P. multocida ssp. septica (4 strains, Syria only), P. canis (3 strains, South Germany only) and Pasteurella-like strains (9 strains). Twelve P. multocida ssp. multocida strains carried capsular antigen D and 7 capsular antigen A. In most cases where multiple samples were examined from one flock, strains with different capsular antigens and/or belonging to different Pasteurella species were isolated (max. 8).