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Introduction: Treatment of urinary tract infections(UTIs), as one of the most common nosocomial and community acquired infections, has remained an important medical problem. Differentiation between susceptibility patterns of nosocomial and community acquired pathogens is important epidemiologically and helps the administration of appropriate antimicrobial drugs. The goal of this study was isolation of the most common causative bacteria, in two groups of 13-35 years old women in Shahrekord city within 6 months period(April-September 2004). Also, the resistance patterns of common isolated organisms in these two groups were compared. Materials and Methods: This is an analythical-cross sectional study. 100 urine samples from women aged 13-35 years old hospitalized in different wards of Hajar and Kashani hospitals(group one) with positive urine cultures were obtained performing clean-catch midstream method. Also 100 urine samples from 13-35 years old women with positive urine culture and acute UTI symptoms from Shahrekord private laboratory (group two) were obtained. The most common causative bacteria in the two groups and the antibacterial sensitivity patterns of isolated organisms were evaluated. Data was analysed using T test. Results: Totally, the most common nosocomial UTI pathogens were E.coli, Klebsiella spp., Staphylococcus saprophyticus, Pseudomonas and Enterobacter spp. In group two, E.coli, Klebsiella spp., Enterobacter spp., Proteus, Staphylococcus saprophyticus and Citrobacter spp. were isolated predominantly. The highest bacterial resistance rate belonged to Ampicillin and Co-trimoxazole. Antibiotics useful in treatment of nosocomial UTI were Ceftizoxim, Nitrofurantoin, Nalidixic acid, Cephalothin and Gentamicin respectively. Nitrofurantoin, Nalidixic acid, Ceftazidim, Gentamicin and Cephalothin were the most effective antibiotics in community acquired UTIs. Conclusion: The emergence of pathogens with alarming rates of resistance, highlights the need for a more rationalized and restricted use of antibiotics in order to minimize the spread of resistant bacterial strains.

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Introduction: Methicillin resistant staphylococcus aureus strains are the most important agents of nosocomial infections. The conventional antibiotic susceptibility methods such as disk diffusion are not suitable for detection of these strains due to their heteroresistancy. Therefore, in this study, agar screen and duplex-PCR were compared in determination of methicillin resistant Staphylococcus aureus (MRSA) strains isolated from nose of personnel in Hajar hospital of Shahre-kord, 2007. Materials and Methods: In this experimental study a total of 204 nasal swabs from personnel of Hajar hospital over a period of 6 months were collected. The specimens were cultured on mannitol salt agar for primary isolation and identification of Staphylococcus aureus strains and their susceptibility pattern to oxacillin was assessed using agar screen method. Finally, using duplex PCR, the isolates were tested for the presence of mecA gene. Results were compared and sensitivity and specificity of the method was determined. Results: In this study, 23 of the 52 (44%) Staphylococcus aureus isolates were resistant to oxacillin using agar screen method. However, mecA gene was detected in 27 of the 52 strains (52%). Our results showed that the sensitivity and specificity of agar screen method in determination of MRSA strains were 81.5% and 96%, respectively comparing with PCR. Conclusion: Oxacillin agar screen, comparing PCR, is an inexpensive, applied and phenotypical method with low false positive and suitable for screening of MRSA. However, due to its relatively high false negative results is not appropriate for screening of MRSA strains isolated from hospital-employed nasal carriers.

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Background: Existence of extended spectrum B-lactamase (ESBL) genes plays an important role in spreading B-lactam antibiotic resistance in the producing strains of these enzymes. The resistance of gram-negative bacteria, such as Pseudomonas aeruginosa, to different antimicrobial agents, especially B-lactam and carbapenem, has increasingly been reported. This study was conducted to determine the prevalence of TEM-1 beta-lactamases in Pseudomonas aeruginosa isolates through Duplex PCR. Materials and Methods: In this descriptive-analytic study, 175 Pseudomonas aeruginosa isolates collected from burn patients were subjected to bacteriological tests. The samples were cultured and identified according to standard methods. Then the frequency of ESBL producing strains was determined via the combined disk method. Using boiling method, DNA was extracted and examined for the existence of TEM-1 gene by Duplex PCR. Results: Out of the 175 Pseudomonas aeruginosa isolates, 66 (37.7%) were ESBL positive, 15.15% of which were positive for TEM-1 B-lactamases resistance gene. Conclusion: Noticing the increasing rate of the ESBLs producing strains, using the appropriate treatment protocol based on the antibiogram pattern of the strains is highly recommended.

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  Background: Colonization with MRSA is no longer limited to hospitalized patients or persons with predisposing risk factors and at present there are several strains of community-acquired MRSA (CA-MRSA). The purpose of this study is to determine etA and etB genes in isolated Staphylococcus aureus strains of clinical samples from teaching hospital in Shahrekord in 2014.

  Materials and Methods: In this descriptive study, 220 clinical samples were collected from teaching hospitals in Shahrekord. The microbiologic characteristics of isolates were determined using microbiologyic standard methods. The MRSA detection was carried out on oxacillin agar medium. The detection of virulence genes etA and etB was used by PCR. Inducible resistance to clindamycin was tested by "D-test".

  Results: In 220 isolates, 110 detected as S. aureus and 13 as MRSA. Inducible clindamycin resistance was seen in 4 (3.5%) of the isolates. The frequency of genes etA, etB in studied strains was 7.6 and 15.3, respectively. Also, Inducible resistance to clindamycin was seen in four isolates(2%).

Conclusion: The results of this study confirme the presence of community- acquired strains in Shahrekord. The results of this study indicate the presence of genes etA and etB in the strains studied, transforming into the strains of Staphylococcus aureus resistant to methicillin obtained from hospital, the development and transfering these strains in the community.