ABSTRACT
To investigate the prevalence of methicillin and aminoglycoside resistance and gene encoding staphylococcal cassette chromosome mec [SCCmec] and aminoglycoside modifying enzymes in clinical isolates of coagulase negative staphylococci[CoNS] from hospitalized patients. One hundred and three isolates of coagulase negative staphylococci[CoNS] were recovered from various clinical samples from August 2013 to November 2014. All the specimens were identified by conventional microbiological methods. These tests were contained colony morphology, gram stain, catalase, slide and tube coagulase. To determine the sensibility of CoNS to antimicrobial components including Cefoxitin[30 micro g], Tobramycin[10 micro g], Kanamycin[30 micro g], Amikacin[30 micro g] and Gentamicin[10 micro g], disk diffusion method was performed by Kirby Bauer antibiotic testing. In order to show the presence of methicillin and aminoglycoside resistant CoNS genes, PCR were demonstrated. In our study the rate of resistance to Cefoxitin, Kanamycin, Gentamicin, Tobramycin and Amikacin were 74[71.8%], 54[52,4%], 51[49.5%], 45[43.7%] and 16[15.5%], respectively. Some strains of CoNS have been detected with intermediate resistance to Kanamycin 4[3.9%], Tobramycin and Amikacin 2[1.9%]. In our study, the distribution of mecA gene among clinical isolates of CoNS was 89[86.4%]. The prevalence of aminoglycoside resistance genes like ant[4 ']-Ia, aac[6 ']/aph[2 "] and aph[3 ']-IIIa were 89[86.4%], 87[84.5%] and 68[66%], respectively. The rate of coexistence of aac[6']-Ie-aph[2''] with aph[3']-IIIa and aac[6']-Ie-aph[2''] with ant[4']-Ia was 65[63%] and 77[74%], respectively. Resistance to aminoglycosides, develops quickly in coagulase-negative staphylococci from clinical areas where these antimicrobial agents are widely used. Therefore, higher investments should be directed towards identifying coagulase-negative staphylococcus species in healthcare institutions and in the community. Overall, Knowing the epidemiology and antibiotic resistance of CoNS is essential to implement the prevention strategies and reducing antibiotic consumptions
ABSTRACT
Aflatoxins are one of the most potent toxic substances that occur naturally. Nowadays extensive attention has been taken to their existence in food and environment, as there is the possibility of harm to humans following chronic exposure to extremely low levels via food chain. Aflatoxin Ml [AFM,] is a hepatic carcinogenic metabolite found in the milk of lactating animals fed with contaminated feed contaminated by aflatoxin Bl [AFB,]. This study aimed to determine the levels of AFM] in produced pasteurized milk in the Ahvaz of city. For this purpose, 100 samples of pasteurized milk from the Ja-mus Factory were analyzed the to determine AFM1 content by using an immunoaffinity column for clean-up and high-performance liquid chromatography [HPLC] with a Cl8 column, a fluorescence detector [excitation 365 nm, emission 435 nm] and a mobile phase of acetonitrile-water [25:75, v/v] at a flow rate of l mL/min. AFM] was detected in all 100 samples of pasteurized milk at concentrations ranging from 0.45 to 9.760 ng/L. The mean concentration of AFMl in the the pasteurized milk samples was 2.7 ng/L, which was below the 50 ng/L, accepted as level of for milk in Iran