DETECTION OF METHICILLIN RESISTANT AND SLIME FACTOR PRODUCTION OF COAGULASE NEGATIVE STAPHYLOCOCCUS SPP. IN BOVINE CLINICAL MASTITIS BY USING PCR

Samia M Sayed ,Essam I Eltoukhy ,Amal A Megahed ,S.m El-Berbawy

doi:10.21608/avmj.2015.170034

Samia M Sayed , Essam I Eltoukhy + Show 2 more

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https://doi.org/10.21608/avmj.2015.170034

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Abstract

The aim of this study was to determine and investigate the slime production of Coagulase negative staphylococci (CoNS) isolates by phenotypic method on Congo Red Agar plates (CRA) and Genotypic detection of icaA, icaD and mecA genes by polymerase chain reaction (PCR). The study was done on 105 milk samples obtained from bovine clinical mastitis and found that 101samples (96.2%) were positive for bacterial culture. CoNS species can be isolated from20 samples with a percentage 19.8%. Their ability to form biofilm as one of the most important virulence factors using Congo Red Agar (CRA) method was investigated, in which 13 out of 17 CoNS isolates (76.47%) were found to be slime producers. By PCR, mecA gene was found in threeout 6 CoNS isolates (50%). Also, six (100%) and three (50%) isolates were positive for icaA gene and icaD gene, respectively, and 3 isolates (50%) were positive for both icaA and icaD genes. In addition, one out of the six CoNS isolates (16.67%) was positive for the presence of icaA, icaD and mecA genes and also it has the ability to form biofilm. Conclusion, findings of the present study demonstrated the ability of CoNS isolated from bovine clinical mastitis to form biofilms. This must be considered as an alarming situation, and so attention must be paid toward implementation of new ways for effective prophylaxis, control, and treatment of such infections in the dairy farms. The prudent use of antibiotics and rapid and continuous screening for resistant microorganisms should be more focused to prevent the emergence and spread methicillin resistant coagulase negative staphylococci, because these strains can cause severe damage to infected sites and may be widespread in the environment.

Highlights

Mastitis in dairy cows is a serious problem as it an economically devasting disease causing immense economic losses in the dairy industry in Egypt (El-Damaty, 2013)
Among Coagulase negative staphylococci (CoNS) (n=17) isolates tested for slime production on Congo Red Agar plates (CRA) plates, 13 isolates (76.47%) were found to be slime producers [Five from 6 Staph. epidermidis isolates (83.3%) and 8 from 11 Staph. saprophyticus isolates (72.7%) were positive for slime production, Fig. 2]
Coagulase-negative staphylococci (CoNS), widely spread in the natural environment and colonizing the skin and mucosa of animals and humans, have been considered non-pathogenic. They are the predominant aetiological factor of bovine mastitis in many countries (Pyörälä and Taponen, 2009 and Bochniarz et al, 2013).Our findings and literature data reveal that the highest incidence of mastitis is caused by bacteria, including coagulase-negative staphylococci prevalent in many countries, according to this study the percentage of CoNS species isolated from milk of cows with clinical mastitis was 19.8%, as shown in Fig. 1 & Table 2

Summary

Introduction

Mastitis in dairy cows is a serious problem as it an economically devasting disease causing immense economic losses in the dairy industry in Egypt (El-Damaty, 2013). Coagulase negative staphylococci (CoNS) have become the most common bovine mastitis isolates in many countries and are regarded as emerging mastitis pathogens (Pyörälä and Taponen, 2009). The high frequency of CoNS and E. coli occurrence indicated insufficient hygiene of housing and milking causing the risk of environmental mastitis (Idriss et al, 2013). Coagulase negative staphylococci are always present on the udder skin and in teat canals; under favourable conditions they permeate the galactogenic pathway to the quarter. The pathogenic mechanisms of CoNS are expressed by two parameters: invasiveness (ability to permeate through protective barriers, to adhere to host cells and to form a biofilm) and toxicity [capacity to produce enzymes and toxins, including haemolysins and proteases], (Bochniarz and Wawron, 2012)

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