[Prevalence of extended-spectrum beta-lactamases and characterization of integron class 1 in extended spectrum beta lactamase-producing Klebsiella pneumoniae in Sina Hospital, Tabriz 2012]

Background: The existence of beta-lactmase among gram-negative bacteria such as Klebsiella pneumoniae, as a significant pathogen in nosocomial infection is the most important cause of resistance against beta- lactam antibiotics family. Class 1 integrons are mobile genetic elements which are mostly prevalent in drug-resistant bacteria. This study was conducted to determine the prevalence of phenotypic and genotypic ESBL-producing strains as well as the incidence of integron class 1 in ESBL-producing strains

Methods: Sixty three isolates of K.pneumoniae, confirmed by biochemical and phenotypic tests, were collected within six months. Susceptibility test was carried out by Disk diffusion method. Prevalence of ESBL producing strains were determined by using Combined Disk Test. Presence of bla TEM, bla SHV gene family and class I integron were detected by PCR technique

Results: Forty five [71.4%] of isolates were ESBL-producing. TEM and SHV gene family were existed in 66.6% and 68.9% of ESBL -producing isolates, respectively. Class I integron were detected in 24 [65%] and 19 [63.3%] of SHV and TEM positive strains, respectively

Conclusion: In present study, increasing level of ESBL producing isolates were confirmed. Also, this study intensely demonstrates the role of integron in the dissemination of ESBL-mediated resistance among the nosocomial isolates. Overall, using the proper treatment procedure according to the antibiogram pattern of the strains is specifically recommended

In vitro susceptibility of pseudomonas aeurogenosa isolated from urinary tract of patients with uti to doxycycline and tigecyclin and comparison with other anti pseudomona antibiotics

Background: Pseudomonas aeruginosa is a gram negative bacillus. Infection with these bacteria usually occur! in patients who hospitalized due to: need for prolonged stay in ICU, those who have intravascular catheters, or indwelling urinary catheters

This Study investigates in vitro susceptibility of pseudomonas aeruginosa which were isolated from patients with UTI to doxycycline, tigecycline, ceftazidime, cefepime, piperacillin/tazobactam, impipenem, meropenem, colistin, ciprofloxacin, nitrofurantoin, amikacin] with standard disk diffusion. Comparing the, susceptibility results of disk diffusion with E.test for doxycycline and tigecycline is another aim. Other purpose of this study was to define MDR pseudomonas aeruginosa susceptibility to doxycycline and tigecycline

Methods: Sixty pseudomonas aeruginosa which was isolated after biochemical and bacteriological test, were entered to study and susceptibility to above antibiotics was tested by disk diffusion. For doxycycline and tigecycline antibiogram by two methods were performed: disk diffusion and Etest

Result: Maximum susceptibility was observed for colistin =95% followed by sensitivity in decreasing order for these antibiotics .Meropenem 76% Imipenem= Cefepime

Conclusion: In vitro susceptibility of isolated pseudomonas aeruginosa to studied antibiotics [with exception of colistin] was less than 80% even for carbapenems

Disk diffusion for doxycycline and tigecycline wasn't effective for differentiation intermediate resistance from sensitive. Calculation of cohens Kappa for agreement was moderate. Most of MDR pseudomonas aeruginosa was resistant to doxycycline and tigecycline

[Prevalence of CTX-3 family gene among clinical isolates of Escherichia coli and Klebsiella pneumoniae from patients hospitalized in Sina Hospital, Tabriz]

Background: Emerging resistance to beta-lactam antibiotics among gram negative bacteria limits their usage. This study was done to determine the frequency of ESBLs producers and presence of CTX-M3 family gene [including CTX-M 3, 15, 22 subfamily] in Escherichia coli and Klebsiella pneumoniae isolated from different clinical specimens in Sina Hospital, Tabriz

Methods: 71 isolates of E. coli and 63 K. pneumoniae were isolated from different clinical specimens sent to Division of Microbiology, Sina Hospital, Tabriz, Iran. Bacteria were identified by conventional phenotypic methods. ESBL production in E. coli and K. pneumoniae was first detected with combined disc method using Mueller-Hinton agar and later presence of CTX-M3 family gene was detected by PCR technique

Results: In this study, 41 [57.74%] E.coli and 45 [71.42%] K. pneumoniae isolates were observed as ESBL producers. Among them, 30 [73.17%] E. coli and 26 [57.77%] K.pneumoniae were found carrying CTX-M3 gene. Among various antibiotics used for ESBL detection, highest resistance towards cefpodoxime [92%] was observed in E.coli, while in K.pneumoniae 90% isolates show resistance towards cefpodoxime and azterornam

Conclusion: Our study revealed that there is a high frequency of ESBLs producing isolates of E. coli and K. pneumoniae in our hospital set up. The problem elucidates the importance of designing more controlled surveillance of antibiotic resistance and need for large-scale epidemiologic studies to identify outcomes of the ESBL-production in gram negative bacilli

Methicillin resistant and susceptible Staphylococcus aureus: appraising therapeutic approaches in the Northwest of Iran

Staphylococcus aureus is a versatile organism causing mild to life threatening infections. The major threat of this organism is its multidrug resistance. The present study was carried out to investigate in - vitro activity of conventional antibiotics routinely prescribed for methicillin resistant S. aureus [MRSA] and methicillin sensitive S. aureus [MSSA] infections in the Northwest of Iran and other alternating therapeutic agents which are recommended for Gram positive organisms. Clinical isolates of S. aureus were subjected to multiplex PCR for simultaneous speciation and detection of methicillin resistance. Antibacterial susceptibility pattern was determined using disk diffusion. The Minimum Inhibitory Concentrations [MICs] were determined using E-test strips. The results revealed presence of nuc gene in all S. aureus isolates detected phenotypically earlier whereas, mec A gene was observed in 54% of strains. On disk diffusion and MIC determination assay, all MRSA and MSSA strains were susceptible to mupirocin [except one MRSA strain], linezolid and teicoplanin. Six vancomycin intermediate S. aureus strains were detected [VISA] with MIC = 4 microg/mL, 5 of them being MRSA. In disk diffusion assay, 17.3% and 3.7% of isolates showed resistance to rifampin and fusidic acid, respectively. However, MIC[50] and MIC[90] tests shows promising in - vitro impact. In - vitro mupirocin was found as an effective prophylactic ointment for nasal S. aureus eradication. Our data emphasize the performance of surveillance exercises to outline the existing antibiotics prescription policies and to slow down the emergence of multidrug resistant strains