Genotypic insights to Panton-Valentine leukocidin positive methicillin-resistant Staphylococcus aureus isolated from cattle mastitis

In this research communication we investigate the prevalence and antimicrobial susceptibility of S. aureus harboring virulent genes responsible for mastitis in cattle of Punjab, Pakistan. A total of 690 milk samples were collected from commercial dairy farms for analysis of the prevalence of subclinical and clinical mastitis and isolation of S. aureus. Virulence ability and methicillin resistance in S. aureus (MRSA) was determined by targeting the pvl (the gene for Panton-Valentine leukocidin) and mecA genes, respectively. A total of 175 S. aureus isolates exhibiting prevalence of pvl gene (6.28%) and mecA gene (22.28%) were determined. Antimicrobial susceptibility testing of pvl positive and negative MRSA against different classes of antibiotics revealed 100% resistance against β-lactams while 100% sensitivity towards tylosin and linezolid.

THEILERIA EQUI INFECTION IN WORKING HORSES OF PAKISTAN: EPIDEMIOLOGY, MOLECULAR CHARACTERIZATION, AND HEMATOBIOCHEMICAL ANALYSIS

Theileria equi is 1 of the emerging and prevailing tick-borne hemoprotozoans adversely affecting the equids worldwide, including Pakistan. The current study aimed to investigate the prevalence and molecular characterization of T. equi in working horses (n = 194), the comparative efficacy of different diagnostic tests, associated risk factors, and hematobiochemical analysis. The blood samples of horses were subjected to microscopic examination, cELISA, and polymerase chain reaction (PCR) and the results revealed a prevalence of 9.79, 21.13, and 13.40%, respectively, for T. equi in working horses. The comparison of microscopy and cELISA results with PCR showed that cELISA had higher sensitivity (84.62%), but lower specificity (88.69%) and accuracy (88.14%) in comparison to microscopy (57.69, 97.62, and 92.27%). Molecular characterization of T. equi by phylogenetic analysis revealed a 61% resemblance of study isolates with each other OL662926, OL662925, and 82% similarity with isolate OL662924 while also showing homology with T. equi isolates of South Africa, South Korea, India, Pakistan, and Brazil. The risk factor analysis revealed a significant association (P < 0.05) of tick control status, previous tick history, tick infestation, house hygiene, deworming/vaccination, and the presence of other livestock species with T. equi infection in horses. The hematobiochemical profile revealed a significant (P < 0.05) decrease in red blood cells (RBCs), hemoglobin (Hb), packed cell volume (PCV), white blood cells (WBCs), platelet (PLT), phosphorus, and an increase in lymphocytes, granulocytes, aspartate aminotransferase (AST), glucose, bilirubin, blood urea nitrogen (BUN), and creatinine in T. equi-infected horses. The current study is the first comprehensive report for comparative evaluation of microscopy, cELISA, and PCR, assessment of epidemiological risk factors as well as hematobiochemical variations due to T. equi infection in Pakistan.

Molecular evidence of β-lactam resistant Staphylococcus aureus in equids with respiratory tract infections: Frequency and resistance modulation strategy

The emergence of antimicrobial-resistant strains in Staphylococcus aureus (β-lactam and methicillin-resistant) is an overwhelming issue worldwide. Using the purposive sampling technique, 217 equids samples were collected from district Layyah which were subjected to culturing followed by genotypic identification of mecA and blaZ genes by PCR. This study revealed that by phenotypic methods, a prevalence of 44.24%, 56.25%, and 47.92% was found for S. aureus, MRSA, and β-lactam resistant S. aureus in equids. While genotypically, MRSA was found in 29.63% and β-lactam resistant S. aureus in 28.26% of equids. In-vitro antibiotic susceptibility testing against S. aureus isolates harboring both mecA and blaZ genes showed a high resistance against Gentamicin (75%), followed by Amoxicillin (66.67%) and Trimethoprim+sulfamethoxazole (58.34%). In an attempt to re-sensitize the resistant bacteria to antibiotics, a combination of antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) was used which revealed synergistic effect of Gentamicin and Trimethoprim+sulfamethoxazole with Phenylbutazone; and Amoxicillin with Flunixin meglumine. Analysis of risk factors revealed significant association with the S. aureus-associated respiratory infection in equids. Phylogenetic analysis of mecA and blaZ genes showed a high resemblance of study isolate's sequences with each other and variable resemblance with already reported isolates obtained from different samples of neighboring countries. This study reports the first molecular characterization and phylogenetic analysis of β-lactam and methicillin resistant S. aureus in equids in Pakistan. Moreover, this study will help in the resistance modulation of resistant antibiotics (Gentamicin, Amoxicillin, Trimethoprim+sulfamethoxazole) and provide a good insight into planning an effective therapeutic regime.

Molecular evidence, risk factors analysis, and hematological alterations associated with Theileria spp. spillover in captive wild mouflon sheep in Punjab, Pakistan

Background

Landscape anthropization and interaction between domestic and wild animals are the major contributing factors involved in the emergence of new pathogens in wild animals. Theileriosis is an emerging issue of wild ungulates, especially in the tropical and subtropical areas of the globe.

Aims

The current study investigated the mouflon sheep for Theileria infection using molecular methods and hematological analysis.

Methods

This study was conducted on a total of 103 captive wild mouflon sheep present in eight different recreational zoos, and wildlife parks in Punjab, Pakistan to investigate the genotypic prevalence of Theileria spp. by targeting 18S rRNA and molecular evidence for Theileria spillover between domestic and wild mouflon sheep by phylogenetic analysis. The association of assumed risk factors and the effect of Theileria spp. on various hematological parameters were also assessed.

Results

The results depicted that Theileria spp. was prevalent in 8 (7.77%, CI 95%: 3.99-14.59%), and 11 (10.68%, CI 95%: 06.07-18.12%) animals based on microscopy, and PCR, respectively. The phylogenetic analysis of the 18S rRNA gene of Theileria spp. from mouflon revealed a close resemblance with T. annulata from domestic animals. The risk factor analysis revealed that tick infestation, enclosure hygiene, previous tick infestation history, and the presence of wooden logs in the enclosure were significantly (P<0.05) associated with the occurrence of Theileria spp. infection in the captive mouflon sheep of Pakistan. Furthermore, a significant reduction in blood parameters like PCV, RBCs count, Hb, and platelets was observed in Theileria-positive animals.

Conclusion

This study is the first evidence at the molecular level to characterize the spillover of Theileria spp. between the captive wild mouflon sheep and domestic animals of Pakistan, and it will be useful in developing control strategies for emerging theileriosis in captive wild animals.