| Abstrakt: |
Staphylococcus aureus has a great ability to induce pathogenicity in different hosts including poultry and cows because it possesses a repertoire of virulence factors, multiple antibiotic resistance mechanisms, and its capability to produce biofilm, in addition to its capacity to gain new resistance genes via integron, which could lead to difficult treatment. For these reasons, this study aims to clarify the type of association between the resistance pattern, the occurrence of some virulence and resistance genes, and the ability to form biofilms among S. aureus isolated from cow milk and poultry samples. A cross-sectional study was conducted to collect a total of 113 samples, 50 milk samples from dairy cattle and 63 swab samples from different clinical cases in poultry and slaughterhouse, during the period from August 2019 to February 2020. The samples were collected randomly from different locations in Karbala and Al-Najaf cities. The samples were manipulated using bacteriological and biochemical methods for isolation and identification of S. aureus, then biofilm production and antimicrobial susceptibility tests were done. Molecular tools were used to study the prevalence of class I integron, some virulence and resistance genes as well as Staphylococcal cassette chromosome (SCCmec). Out of 113 samples cultured and identified, 51 (45.2%) isolates were characterized as S. aureus. Regarding resistance rates of S. aureus, the isolates were most frequently resistant to penicillin (62.7%), and 70.5% of S. aureus isolates were found to have had MAR index of 0.2 and above. Remarkably, the results showed that 21 (41.2%) isolates were multidrug-resistant to three or more antibiotic classes, two (6.7%) of which were PDR isolates in this study, while 16 (31.4%) of S. aureus isolates where detected as MRSA by molecular method. Also, SCCmec typing of MRSA isolates revealed that 7 (43.8%) MRSA isolates were carrying type IV SCCmec. Moreover, the molecular detection of eta and intI1 genes revealed that 3 (5.8%) isolates were positive for the eta gene, and 30 (58.8%) of the isolates were positive for intI1. Correspondingly, a significantly higher rate of strong biofilm producers (60%) among S. aureus isolated from cow milk than found in poultry isolates (40%) (P ≤ 0.01). the results of this study indicate the risk of spread of Staphylococcus with different resistance patterns, also the evidence from this study suggests the importance of monitoring of the prevalence of MRSA in broilers and cattle. [ABSTRACT FROM AUTHOR] |
