RESUMO
@#The emergence of methicillin-resistant Staphylococcus aureus (MRSA) infection is one of the greatest threats to both animal and human health. Our investigation was aimed to identify and differentiate between MRSA and methicillin-sensitive Staphylococcus aureus (MSSA) recovered from mastitic milk using MALDI-TOF mass spectrometry compared with phenotypic methods and studying their susceptibility to various antibiotics. Four hundred milk samples from mastitic animals (cows, sheep, goats, and dromedary camels) were investigated. Phenotypic identification of S. aureus was made through MASTASAPH Latex test, STAPH ID 32, and Vitek 2 system. The proteomic characterization of S. aureus was done by MBT. The Kirby Bauer method was accomplished to detect the resistance of S. aureus strains to antibiotics. The results of the MASTASAPH Latex test, revealed that 54 (46%) were recognized as S. aureus. All S. aureus isolates were identified by MBT with a score of more or equal 2.00. Several peaks were identified in the mass of 4590 Da, 4863 Da, and 4938 Da for MSSA and in the mass of 2636 Da and 3009 Da for MRSA. The MSP dendrogram demonstrated that the S. aureus isolates were classified into one group with a distance level of less or equal 400. The percentage of S. aureus resistance against carbenicillin, erythromycin and kanamycin was 94.4%, 38.88%, and 33.33%, respectively. In conclusion, S. aureus bacteria are among the key triggers for mastitis in Saudi Arabia. MBT is reported to be not only the rapid tool to identify S. aureus but also able to discriminate MRSA from MSSA.
RESUMO
Diagnosis of contagious caprine pleuropneumonia (CCPP) in Saudi Arabia mainlydepends on clinical signs and post-mortem findings, in addition to limited usage of latexagglutination test (LAT). In this study, a PCR method specific for detection of Mycoplasmacapricolum subspecies capripneumoniae (Mccp) was used as a direct confirmatory methodand to compare it with clinical signs, necropsy lesions and LAT. During the 2016-2017 year,samples of serum, pleural fluid, lung tissue and nasal swab were collected from 40 goats withclinical signs of CCPP, which were selected from goats brought to the veterinary clinic ofQassim University from 18 goat herds and nine localities. Epidemiological data revealed34.1%, 27.8% and 81.6% morbidity, mortality and case fatality rates, respectively. At necropsy,31 of 40 goats (77.5%) were found with lesions matching those of CCPP. Molecular findingssupported the suitability and applicability of PCR as a reliable method to diagnose andconfirm CCPP directly from clinical samples. The disease was confirmed by PCR in 35 goatsout of 40 (87.5%), 15 herds out of 18 (83.3%) and in all localities. Sera of 32 goats (80%) werefound positive by LAT. Four of the five goats and two of the three herds negative by PCR werealso negative by LAT and necropsy examination. Therefore, PCR sensitivity was considered97.2% (35/36). Compared to the claimed high specificity and sensitivity of the used PCRmethod, diagnosis of CCPP based on clinical signs was found less specific and necropsyexamination and LAT were less sensitive. It was concluded that molecular detection of Mccpdirectly in clinical samples should routinely be used to confirm diagnosis of CCPP in theregion of study, prevent economic impact of wrong diagnosis and to hasten control process.