Molecular study on Pasteurella multocida and Mannheimia granulomatis from Kenyan Camels (Camelus dromedarius)

Background Outbreaks of a Haemorrhagic Septicaemia (HS) like disease causing large mortalities in camels (Camelus dromedarius) in Asia and in Africa have been reported since 1890. Yet the aetiology of this condition remains elusive. This study is the first to apply state of the art molecular methods to shed light on the nasopharyngeal carrier state of Pasteurellaceae in camels. The study focused on HS causing Pasteurella multocida capsular types B and E. Other Pasteurellaceae, implicated in common respiratory infections of animals, were also investigated. Methods In 2007 and 2008, 388 nasopharyngeal swabs were collected at 12 locations in North Kenya from 246 clinically healthy camels in 81 herds that had been affected by HS-like disease. Swabs were used to cultivate bacteria on blood agar and to extract DNA for subsequent PCR analysis targeting P. multocida and Mannheimia-specific gene sequences. Results Forty-five samples were positive for P. multocida genes kmt and psl and for the P. multocida Haemorrhagic Septicaemia (HS) specific sequences KTSP61/KTT72 but lacked HS-associated capsular type B and E genes capB and capE. This indicates circulation of HS strains in camels that lack established capsular types. Sequence analysis of the partial 16S rRNA gene identified 17 nasal swab isolates as 99% identical with Mannheimia granulomatis, demonstrating a hitherto unrecognised active carrier state for M. granulomatis or a closely related Mannheimia sp. in camels. Conclusions The findings of this study provide evidence for the presence of acapsular P. multocida or of hitherto unknown capsular types of P. multocida in camels, closely related to P. multocida strains causing HS in bovines. Further isolations and molecular studies of camelid P. multocida from healthy carriers and from HS-like disease in camels are necessary to provide conclusive answers. This paper is the first report on the isolation of M. granulomatis or a closely related new Mannheimia species from camelids

Significant veterinary research on the dromedary camels of Kenya: Past and Present

Abstract The dromedary camel (Camelus dromedarius) is extremely well adapted to hot and arid environments owing to its unique anatomical, physiological and behavioural features. Dromedaries do not only survive where other domestic species do not, but they also carry out work and produce valuable food products for the benefit of people. Dromedaries offer the only means of utilizing large areas of arid lands in many countries around the globe. The camel´s feed and water needs are special. They browse and graze on vegetation that is inaccessible or unpalatable to other lifestock and many other animals, and they have a remarkable tolerance to dehydration. The virtues of the dromedary camels in Kenya and their importance in food security of pastoralist people have been more and more recognized over the last decades. Pastoralism is replacing agro-pastoralism in some areas of sub-Saharan Africa due to climate change. In areas where the growing period will be too short and no longer support crop cultivation, pastoralism may become the only sustainable source of food production. A compilation of significant research done on the dromedaries of Kenya during recent decades is reviewed, particularly regarding veterinary aspects of the most prevalent diseases that have been and are being studied. Trypanosomosis (surra) has received most attention, followed by camelpox, mastitis and milk hygiene, camel calf losses, sarcoptic mange and other skin diseases, helminthosis, haemorrhagic septicaemia and respiratory infections

Genomic Characterization and Antimicrobial Susceptibility of Dromedary-Associated Staphylococcaceae from the Horn of Africa.

Members of the Staphylococcaceae family, particularly those of the genus Staphylococcus, encompass important human and animal pathogens. We collected and characterized Staphylococcaceae strains from apparently healthy and diseased camels (n = 84) and cattle (n = 7) in Somalia and Kenya. We phenotypically characterized the strains, including their antimicrobial inhibitory concentrations. Then, we sequenced their genomes using long-read sequencing, closed their genomes, and subsequently compared and mapped their virulence- and resistance-associated gene pools. Genome-based phylogenetics revealed 13 known Staphylococcaceae and at least two novel species. East African strains of different species encompassed novel sequence types and phylogenetically distant clades. About one-third of the strains had non-wild-type MICs. They were resistant to at least one of the following antimicrobials: tetracycline, benzylpenicillin, oxacillin, erythromycin, clindamycin, trimethoprim, gentamicin, or streptomycin, encoded by tet(K), blaZ/blaARL, mecA/mecA1, msrA/mphC, salA, dfrG, aacA-aphD, and str, respectively. We identified the first methicillin- and multidrug-resistant camel S. epidermidis strain of sequence type (ST) 1136 in East Africa. The pool of virulence-encoding genes was largest in the S. aureus strains, as expected, although other rather commensal strains contained distinct virulence-encoding genes. We identified toxin-antitoxin (TA) systems such as the hicA/hicB and abiEii/abiEi families, reported here for the first time for certain species of Staphylococcaceae. All strains contained at least one intact prophage sequence, mainly belonging to the Siphoviridae family. We pinpointed potential horizontal gene transfers between camel and cattle strains and also across distinct Staphylococcaceae clades and species. IMPORTANCE Camels are a high value and crucial livestock species in arid and semiarid regions of Africa and gain importance giving the impact of climate change on traditional livestock species. Our current knowledge with respect to Staphylococcaceae infecting camels is very limited compared to that for other livestock species. Better knowledge will foster the development of specific diagnostic assays, guide promising antimicrobial treatment options, and inform about potential zoonotic risks. We characterized 84 Staphylococcaceae strains isolated from camels with respect to their antimicrobial resistance and virulence traits. We detected potentially novel Staphylococcus species, resistances to different classes of antimicrobials, and the first camel multidrug-resistant S. epidermidis strain of sequence type 1136

Field-applicable recombinase polymerase amplification assay for rapid detection of Mycoplasma capricolum subsp. capripneumoniae

Contagious caprine pleuropneumonia (CCPP) is a highly contagious disease caused by Mycoplasma capricolum subsp. capripneumoniae that affects goats in Africa and Asia. Current available methods for the diagnosis of Mycoplasma infection, including cultivation, serological assays, and PCR, are time-consuming and require fully equipped stationary laboratories, which make them incompatible with testing in the resource-poor settings that are most relevant to this disease. We report a rapid, specific, and sensitive assay employing isothermal DNA amplification using recombinase polymerase amplification (RPA) for the detection of M. capricolum subsp. capripneumoniae. We developed the assay using a specific target sequence in M. capricolum subsp. capripneumoniae, as found in the genome sequence of the field strain ILRI181 and the type strain F38 and that was further evidenced in 10 field strains from different geographical regions. Detection limits corresponding to 5 × 103 and 5 × 104 cells/ml were obtained using genomic DNA and bacterial culture from M. capricolum subsp. capripneumoniae strain ILRI181, while no amplification was obtained from 71 related Mycoplasma isolates or from the Acholeplasma or the Pasteurella isolates, demonstrating a high degree of specificity. The assay produces a fluorescent signal within 15 to 20 min and worked well using pleural fluid obtained directly from CCPP-positive animals without prior DNA extraction. We demonstrate that the diagnosis of CCPP can be achieved, with a short sample preparation time and a simple read-out device that can be powered by a car battery, in < 45 min in a simulated field setting

Microorganisms associated with sub-clinical Mastitis in the Kenyan Camel (Camelus dromedarius)

Over a period of 11 months, 435 milk samples were collected from 92 lactating female camels on a ranch in Northern Kenya that was traditionally managed. The samples were examined bacteriologically to determine the causative agents of camel mastitis in Kenya. 145 samples (33.3%) yielded no growth. The most prevalent pathogen was group D (non-enterococci) streptococci, which was 30.0% of the total isolates. The other dominant organisms were coagulase-negative staphylococcus (CNS)(20.1%), as follows: Staphylococcus aureus (16.0%), Streptococcus agalactiae (1.5%) and Streptococcus dysgalactiae (3.6%). Although Streptococcus agalactiae and Streptococcus dysgalactiae appear low in prevalence, they were associated with subclinical mastitis. However, Streptococcus agalactiae and S. aureus were ranked as infectious pathogens while the group D streptococci, Streptococcus dysgalactiae, CNS, coliforms and Micrococci were ranked as environmental pathogens. J. Trop. Microbiol Vol.2 2003: 11-1

Camel Streptococcus agalactiae populations are associated with specific disease complexes and acquired the tetracycline resistance gene tetM via a Tn916-like element

Camels are the most valuable livestock species in the Horn of Africa and play a pivotal role in the nutritional sustainability for millions of people. Their health status is therefore of utmost importance for the people living in this region. Streptococcus agalactiae, a Group B Streptococcus (GBS), is an important camel pathogen. Here we present the first epidemiological study based on genetic and phenotypic data from African camel derived GBS. Ninety-two GBS were characterized using multilocus sequence typing (MLST), capsular polysaccharide typing and in vitro antimicrobial susceptibility testing. We analysed the GBS using Bayesian linkage, phylogenetic and minimum spanning tree analyses and compared them with human GBS from East Africa in order to investigate the level of genetic exchange between GBS populations in the region. Camel GBS sequence types (STs) were distinct from other STs reported so far. We mapped specific STs and capsular types to major disease complexes caused by GBS. Widespread resistance (34%) to tetracycline was associated with acquisition of the tetM gene that is carried on a Tn916-like element, and observed primarily among GBS isolated from mastitis. The presence of tetM within different MLST clades suggests acquisition on multiple occasions. Wound infections and mastitis in camels associated with GBS are widespread and should ideally be treated with antimicrobials other than tetracycline in East Africa

Draft genome sequences of seven Streptococcus agalactiae strains isolated from Camelus dromedarius at the horn of Africa

We present draft whole-genome sequences of seven Streptococcus agalactiae strains isolated from Camelus dromedarius in Kenya and Somalia. These data are an extension to the group B Streptococcus (GBS) pangenome and might provide more insight into the underlying mechanisms of pathogenicity and antibiotic resistance of camel GBS