التفاصيل البيبلوغرافية
| العنوان: |
GENETIC DIVERSITY OF MANNHEIMIA HAEMOLYTICA ISOLATES FROM BOVINE RESPIRATORY DISEASE CASES IN MISSOURI. |
| المؤلفون: |
Kittana, Hatem, Ogunbadewa, Anthony J., Calcutt, Michael, Gull, Tamara, Odemuyiwa, Solomon O. (Wole) |
| المصدر: |
Proceedings of the Annual Meeting of the United States Animal Health Association; 10/6/2022, Vol. 126, p38-38, 1p |
| مصطلحات موضوعية: |
MANNHEIMIA haemolytica, HEALTH of cattle, RESPIRATORY diseases, SALMONELLA enterica, DNA sequencing |
| مستخلص: |
Mannheimia haemolytica (MH) is the most frequently isolated bacterium from the lungs of cattle with bovine respiratory disease complex. Capsular serotype and expression of leukotoxin A (lktA) correlate with pathogenicity in MH isolates. We investigated the genetic diversity of MH isolates in diseased lungs of cattle submitted to the VMDL. MH isolates were identified using MALDI-TOF and probed with primers specific for MH and lktA genes. Primers specific for serotypes 1,2, and 6 were used to type isolates. Isolates negative for lktA and MH were subjected to whole genome sequencing. MALDI-TOF identified 95 isolates were identified as M haemolytica and four as M varigena (MV). Two isolates, Salmonella enterica and Pseudomonas gessardii, served as negative controls. Of 95 isolates identified as MH, 3 (3.2%) were non-hemolytic; two of four MV isolates were hemolytic. MH-specific primers confirmed 83 (90.2%) of hemolytic MH isolates (MH+). LktA gene was confirmed in 73 (88.0%) of MH+ isolates. Serotypespecific primers typed 24 (32.9%), 7(9.6%) and 14 (19.2%) of 73 beta-hemolytic LktA+ MH isolates as serotypes 1, 2, and 6, respectively. While 4 (5.6%) samples were not typable, serotype classification of 24 (32.9%) samples was ambiguous since they tested positive for both serotype 1 and 2. Twenty isolates that could not be unambiguously typed as beta-hemolytic, LktA-expressing, MALDI-TOF positive MH were further characterized using whole genome sequencing. Initial analyses showed that 14 of the isolates were M hemolytica while 3 were M varigena; 3 isolates were unclassifiable. Of the 20 isolates, 5 had multidrug resistance genes for five different groups of antibiotics. We identified plasmids and mobile genetic elements (MGE) that may play a role in horizontal gene transfer. This study showed the presence of a heterogeneous population of Mannheimia species in lung tissues submitted to our laboratory from Missouri cattle with respiratory disease. The presence of MGE is a significant finding that may contribute to the spread of antibiotic resistance to other bacterial species. [ABSTRACT FROM AUTHOR] |
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| قاعدة البيانات: |
Complementary Index |
