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Showing 18 results for Ciprofloxacin

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Volume 13, Issue 52 (9-2005)

Background & Objectives: Aeromons is the cause of various infections in humans and has been isolated from different food samples and even drinking water. Research studies report the prevalence of the bacteria in diarrheic patients to be equal to or higher than shigella. Regarding the contradictory reports this study was conducted to investigate the prevalence and significance of Aeromonas in children's dysentery and their sensitivity to antibiotics in Tehran in 2003-2004. Materials & Methods: In this descrpitive study 310 stool samples of diarrheic children under 10 years of age were tested for infection to Aeromonas, plesiomonas, bacterial pathogens such as salmonella, shigella, enteropathogenic E.coli and enteric parasites and susceptibity of these agents to antibiotics was assessed through diffusion disc method on aeromonas isolates. Data were analysed using discriptive and analytical statistics (χ 2 , t-test and, Fisher exact test). Results: The results showed that Aeromonas prevalence was 4.5% and higher than salmonella and enteropathogenic E.coli in diarrheic children and it was the second leading pathogen after shigella. All Aeromonas strains were susceptible to ceftizoxime, ciprofloxacin, gentamicin and resistant to ampicillin. Conclusion: Aeromonas species are of etioloical significance in diarrheic children and they must be taken into account in bacteriologic survey of the stool samples. More research is recommended.

Na Mozafari, S Talaei, Hr Amirmoghadami, S Talaei,
Volume 14, Issue 55 (6-2006)

Background & Objectives: Chronic Otitis Media (COM) remains one of the most common childhood chronic infectious diseases worldwide. This study was carried out to determine the organisms inducing COM and their drug resistance patterns in Zanjan. Materials & Methods: This cluster cross-sectional study was conducted on 100 patients suffering from COM in the age range of 18-45. COM specimens were obtained in operating room and then cultured on 4 different media. Following the diagnostic tests and identifying the bacteria, their susceptibility to antibiotics was assessed. Results: The most common isolated bacteria were Pseudomonas aeruginosa (24.7%), Staph ylococcus aureus (17.6%) and Proteus spp (15.2%). The results of bioassay tests for isolated bacteria were as follows: Pseudomonas aeruginosa had the highest resistance to cefixime and co-trimoxazol (100%). The highest resistance of Staphylococcus Aureus was to co-trimoxazol (70%) and cefixime (50%). Conclusion: Regarding the multi-bacterial etiology of COM and high prevalence of antibiotic resistance, identification of causative bacteria and bioassay test prior to any therapeutic procedure seams necessary.

Dr Hosien Sarmadan, Dr Farshideh Didgar,
Volume 15, Issue 61 (12-2007)

Background and objective: Lower urinary tract infection is one of the most common infections among young women. The high prevalence of this infection necessitates the administration of appropriate antibiotic and minimizing the treatment period. In this study we examined and compared the effect of single-dose therapy of ciprofloxacin with seven-day therapy in women with lower UTI. Materials and Methods: The study cases comprised of 140 women aged 13-25 years with uncomplicated lower UTI who referred to Vali-Asr hospital in Arak. The patients were randomly assigned into two groups of 70. One group received a single-dose ciprofloxacin (1000 mg) while the other group received a seven-day ciprofloxacin (250 mg twice daily). Urine culture was performed for all the patients three times. In case of primary positive culture the patient would enter the study, and the second culture was carried out to investigate the response to the treatment, whereas the third culture was carried out to study the recurrence. Finally, the results of the two groups were analyzed. Results: Out of 140 patients participating in the study, 23 cases did not respond to the treatment. In the final assessment 14 non-responsive patients belonged to single-dose group while 9 patients were in seven-day therapy group. Conclusion: The research findings showed that there was no significant difference between the two groups (p=0.183) in response to the drug and recurrence. This indicates the equal efficacy of single-dose treatment and one-weak therapy of ciprofloxacin in women with lower UTI.

Sz Torabi, B Falak-Ul-Aflaki, F Moezzi,
Volume 15, Issue 61 (12-2007)

Background and Objective: Extensive use of antibiotics in medicine has led to resistance of microorganisms in urinary tract infection (UTI) in both children and adults. Therefore, conducting studies on antibiotic susceptibility is needed for selection of antibiotics based on regional studies.

 Materials and Methods: During the year 2006 urine samples from all symptomatic patients admitted to neonatal, pediatrics, obstetric and neurologic wards were collected through midstream clean-catch, catheterization, or urine bags. An antibiogram test was performed for all 118 urine samples which were culture positive. Results: The most common organisms found in neonatal urine culture were klebsiella pneumonia (44/5%) followed by Escherichia coli (33/5%). Escherichia coli was the most common organism in pediatrics (41%), obstetric (46%), and neurologic wards (73%). Resistance to ampicillin (82/6%) and cefixim (73/6%) was significant in all samples. Ciprofloxacine was the most effective drug against E.coli and klebsiella pneumonia in all wards (resistance rate: 24/1%) followed by nitrofurantion (resistance rate: 41/4%), ceftriaxone (resistance rate: 44/8%) and amikacin (resistance rate: 51/9%). Vancomycine was the most effective drug against staphylococcus epidermidis (resistance rate: 37/1%) followed by cephtasidim (resistance rate: 40/1%) and ciprofloxacine (resistance rate: 48/5%). Conclusion: Unfortunately due to irrational use of antibiotics, high resistance to ampicillin, cefixim, gentamycin, cotrimoxazol, and some other drugs was observed. Continuous studies regarding the drug resistance are recommended for better assessment in the future.

Aa Jamshidi, A Matbooei,
Volume 16, Issue 62 (3-2008)

Background and Objective: Gastroenteritis is one of the most important diseases in the world. This disease is more critical among children, people with immune deficiency and the sufferers from mal-nutrition. Shigella spp. as the most important cause of dysentery, causes much mortality around the world. Increasing antibiotic resistance is one of the major health problems. This research aimed to study the pattern of antibiotic resistance of Shigella spp. In Zanjan Shahid Beheshti Hospital. Materials and Methods: Shigella spp. was isolated from stool samples of diarrheic patients during 2003-2007 using common microbioloyic methods. They were examined for serotyping and antibiogram using disc diffusion method. Results: Shigella spp were found in 134 out of 682 (19.6%) diarrheic stool samples. They comprised of 53% males and 47% females. The highest number of positive samples was found in August and the lowest number was seen in March. The shigella species isolated from 134 positive cultures, identified as sh.flexeneri (62.7%), sh.boydii (20.1%) and sh.dysenteriae (17.2%). In the antibiogram, ciprofloxacin was the most sensitive antibiotic (88.8%) and Ampicillin showed the highest resistance (100%). Conclusion: Due to irregular use of antibiotics and increasing antibiotic resistance to Shigella species it can be suggested that some of antibiotics can be omitted from the list of drug choice.

R Moniri, M Shafiee,
Volume 16, Issue 64 (9-2008)

The Survey on Prevalence and Risk Factors for Antibiotic-Resistant Staphylococcus Aureus Isolated from Samples in Kashan Hospitals Moniri R1, Shafiee M2 1 Dept of Microbiology and Immunology, Kashan University of Medical Sciences, Kashan, Iran 2 Pasteur Institute of Iran, Tehran, Iran Corresponding Author's Address: Dept of Microbiology and Immunology, Kashan University of Medical Sciences, Kashan, Iran E-mail: Received: 20 July, 2008 Accepted: 17 Nov, 2008 Background and Objective: Methicillin-resistant Staphylococcus Aureus (MRSA) is a serious problem in hospitals. The purpose of this study was to determine the prevalence and related risk factors of methicillin resistance S. aureus isolated from clinical specimens in Kashan hospitals. Materials and Methods: This descriptive study was carried out on 100 S.aureus strains isolated from patients admitted to Kashan hospitals in 2006- 2007. Strains were inoculated on blood agar containing 5% sheep blood and 7.5% mannitol salt agar media, and were incubated at 35°C for 24 hours. The isolated S. aureus strains were identified using gram staining, catalase test, coagulase tube test, growth on chrome agar and the DNAse test. The antibiotic sensitivity test was determined by disk diffusion method. Variables including age, sex, previous hospitalization, duration of hospitalization, previous antibiotic therapy, and type of the disease, were recorded in questionarres. Data were analyzed statistically by the Chi-square and Fischer’s exact tests. Results: Penicillin and Ciprofloxacin revealed the highest and lowest resistance rates respectively (99%, vs 11 %). Meticillin resistance was 22% and an intermediate resistance to Vancomycin was detected in 7% of isolates. A significant correlation was established among the presence of resistant staphylococci with age of more than 46 years old (P<0.040), previous hospitalization (P<0.000), hospitalization for more than 1 week (P<0.000), previous antibiotic therapy (P<0.004), and administration of antibiotics for more than 1 week (P<0.002). Conclusion: Awareness about the prevalence of antibiotic resistant S.aureus and identification of risk factors for infection with resistant isolates is essential to help clinicians, choosing appropriate antibiotic regimen.

Mm Soltan Dallal, M Sanaei, M Taremi, S Moezardalani, H Edalatkhah, M Azimirad, Mr Zali,
Volume 17, Issue 68 (9-2009)

Background and Objective: Microbial food safety and food borne pathogens with antibiotic resistance or multidrug resistance is an increasing public health concern worldwide. Campylobacter is one of the most common causes of acute bacterial gastroenteritis in human, especially in children. The objects of our study were to determine the frequency and antibiotic resistance pattern of thermopilic Campylobacter spp. (jejuni and coli) in raw poultry and beef isolates. Materials and Methods: The samples of raw chicken and beef (packaged and non-packaged) were purchased from the different parts of Tehran and then transferred to laboratory. Specimens were enriched in Preston Broth and cultured on Campylobacter selective agar medium for 48h. After that, suspected colonies isolated and confirmed by standard tests. Antimicrobial sensitivity was carried out using disk diffusion method. Results: Out of 379 samples, Campylobacter spp was identified in 109(28.8%) cases comprising of C.jejuni (76.1%) and C.coli (23.9%). The rate of isolation from chicken (49.7%) was more than that of beef (7.9%). There was a significant correlation between the rate of contamination by Campylobacter and type of meat (P<0.05). 41.8% of packaged and 54.1% of non-packaged (P value = 0.197) chicken samples and 4.5% of packaged and 9.8% of non -packaged beef samples (P value = 0.105) were contaminated with Campylobacter. Among the variety of tested antibiotics, the highest resistance was found for Nalidixic acid (71%) and Ciprofloxacin (46.7%). None of the strains were observed to be resistant to Gentamicin. Conclusion: The high prevalence of Campylobacter jejuni contamination in chicken meat represents the absence of hygiene rules in slaughtering the poultries and transferring process. Isolated strains from meat show increasing susceptibility against Fluroquinolone. The reason of susceptibility increment in isolated Campylobacter strains could be misusage of consumption of antibiotics such as Enrofloxcin in chicken farms. Sensitivity to Gentamicin makes this drug a suitable alternative for treatment of Campylobacter infection.

F Didgar, H Sarmadian, N Zarin Far, M Rafiee, M Choghae,
Volume 20, Issue 80 (7-2012)

Background and Objective: Brucellosis is an endemic disease in Iran that has a worldwide spread and is associated with chronic disabilities in humans. Combination therapy of brucellosis leads to recovery of symptoms, shortening of the symptomatic intervals, and decrease in the rate of relapse and drug resistance. Considering the use of rifampin in the treatment of tuberculosis, and the necessity for an alternative treatment in regions endemic for both tuberculosis and brucellosis, in this study we compared the efficiency of the WHO's standard regimen of rifampin-doxycycline (RD) versus ciprofloxacin-doxycycline (CD) for the treatment of brucellosis. Materials and Methods: This randomized controlled trial was performed on 90 patients, affected with brucellosis, who were referred to the Infectious Disease Clinics at Arak University of medical sciences. The patients were randomly divided into two groups: the DR group, received 100 mg of Doxycycline twice a day and 300 mg of rifampin Bid daily for eight weeks and the CD group, received 100 mg of doxycycline plus 500 mg of ciprofloxacin twice a day for eight weeks. The patients were analyzed for the relief of symptoms, drug side effects, and laboratory findings during the treatment. Results: In this study, the rate of symptom relief and laboratory findings in both groups were similar. The relief of symptoms was seen in 93.2% and 83.9% of the patients for the DR and CD groups, respectively (P=0.182). The side effects of the drug were not significant in either groups, with no significant difference, and did not lead to discontinuation of the therapy. Conclusion: Due to the similar efficacy of CD and DR regimens in the treatment of brucellosis and considering the usage of rifampin in regions with high prevalence of tuberclusis, the CD regimen is recommended as an appropriate treatment.

Z Tavajjohi, R Moniri, A Khorshidi, M Rohani,
Volume 20, Issue 82 (7-2012)

Background and Objective: Pseudomonas aeruginosa is the most common pathogen causing nosocomial infections. The aim of this study was to determine the antimicrobial susceptibility pattern and prevalence of ESBLs in clinical and environmental isolates of P. aeruginosa by phenotypic and genotypic techniques. Materials and Methods: In this descriptive study, a total of 100 P. aeruginosa strains isolated from different clinical and environmental specimens were used. The antibiotic resistance pattern to eight antimicrobial agents was determined by disk diffusion method. The ESBLs producing strains were confirmed by double-disk-diffusion test, and the blaTEM-1, blaSHV-1, blaSHV-5, blaCTX-M-1, blaCTX-M-2, blaCTX-M-3, blaCTX-M-9, blaOXA-1, blaGES-1, and blaGES-2 genes were detected by PCR. Results: Piperacillin and ciprofloxacin showed the highest (36%) and the lowest (16%) resistance against the isolates, respectively. Thirty percent of the total isolates were resistant to at least three classes of antibiotics. By double-disk-diffusion test, eight strains (8%) were ESBL positive. According to the PCR results, the blaGES-2, blaSHV-1, blaSHV-5, and blaCTX-M-1 genes were detected in 8, 2, 2, and 1 isolates of ESBLs producing strains respectively. Conclusion: The blaGES-2 gene displayed an expanded hydrolysis profile to the antibiotic imipenem. In fact, this enzyme, which plays an important role in resistance to imipenem, was detected in all ESBLs producing P. aeruginosa strains. This is the first report describing blaGES-2 producing P. aeruginosa in Iran.

A Ardebili, L Azimi, H Mohammadi-Barzelighi, P Owlia, M Beheshti, M Talebi, M Jabbari, A Rastegar Lari,
Volume 20, Issue 83 (8-2012)

Background and Objective: Acinetobacter baumannii is an important human pathogen that has been a focus of attention in recent years. These bacteria are a leading cause of therapeutic resistant nosocomial infections especially in burned or hospitalized patients in intensive care Units. The aim of this study was to isolate the Acinetobacter baumannii species from the wounds of burned patients and to determine antimicrobial resistance pattern of these bacteria for selection of appropriate antibiotics. Materials and Methods: Samples were collected from patients and transferred to the laboratory under standard conditions. Bacteria were isolated and purified by conventional culture methods. Identification of bacterial species was performed by standard biochemical tests. The isolates that were identified as Acinetobacter baumannii were subsequently tested for antibiotic resistance by the disk diffusion agar method for 17 different antibiotics. The tests were carried out on Muller Hinton agar (MHA) plates and incubated at 35˚C for 18 hrs. The minimum inhibition concentrations were determined for 5 common therapeutic antibiotics. Results: Out of the 65 clinical Acinetobacter baumannii isolates collected, 61 (94%) were multi drug resistant (MDR). Ceftazidime and aztronam (98%) were the most effective antibiotics against Acinetobacter baumannii. To determine the MIC, the highest levels of antibiotic resistance were seen against ceftazidime, cefepime, and ciprofloxacin. Conclusion: Our results confirm the high prevalence of Acinetobacter baumannii resistant isolates and the ensuing therapeutic problems in Iran. Determination of the resistance patterns of these bacteria according to MIC is necessary, and it can be especially helpful in treatment of burned patients.

J Norouzi, A Akhavan Sepahy, N Bazzazzadeh,
Volume 21, Issue 88 (7-2013)

Background and Objective Widespread use of co-trimoxazole in urinary tract infection treatments and its incorrect use has led to the emergence of co-trimoxazole resistant E. coli strains. The aim of this study was to evaluate sul2 gene among E.coli isolates of patients admitted to the clinical centers of Khoy city. Materials and Methods: Three hundred urine samples were collected from clinical centers of Khoy city. Among them, 100 E.coli isolates were confirmed by standard biochemical tests. Furthermore, the antibiotic susceptibility tests to 10 antibiotics were performed by the-disk-agar diffusion (DAD) method. Also, MIC and MBC were evaluated for co-trimoxazole by microdilution broth method. Finally, PCR was done in order to find sul2 gene in resistant isolates. Results: Of 100 isolates, 71(71%) were resistant to co-trimoxazole out of which 57(80%) had sul2 gene. This gene was recognized in sulfonamides-resistant isolates which did not create any zone of inhibition. Also, the isolates with sul2 gene were found to be simultaneously resistant to ampicillin, nalidixic acid and ciprofloxacin. In co-trimoxazole-resistant isolates, MIC and MBC for Co-trimoxazole were calculated 16 and 32μg/ml. Conclusion: This study was the first of its kind in Iran with the main objective of manifesting the presence of sul2 gene in E.coli. The results of the present study indicate that antibiotic-resistance percentage in Khoy city reaches to 71%. In such a situation, it is inevitable to see resistance to all common antibiotics currently prescribed to patients at clinical centers which will, in turn, result in treatment failures.
Ar Esmaeilzadeh, M Ebtekar, Ar Biglari, S Saraf, T Yoshimoto,
Volume 22, Issue 91 (4-2014)

Background and Objective: Breast cancer, assumed as a difficult -to –treat disorder across the world, is the most common malignancy among women. Over decades, significant advances in breast cancer immunotherapy and tumor immune biology have been brought about. In vitro studies of the effect of various cytokines have been conducted in breast tumor. Among Interleukins, IL-27 -a novel cytokine- is associated with specific properties. Moreover, IL-27 contributes to the Th1 induction and also acts as a pro- inflammatory cytokine. The aim of this study was to evaluate the IL-27 anti-proliferative effects on 4T1 cell line in vitro. Materials and Methods: In this study, 4T1 cells were cultured in RPMI1640. mIL-27 gene was cloned, cells were transfected and recombinant protein was produced. Then, anti-proliferative effect of IL-27 on 4T1 breast cancer cell line was evaluated. Results: Our results indicated that IL-27 could suppress 4T1 cell proliferation significantly (p<0/01). Cell to cell interactions and also morphology of the cells were remarkably changed in comparison to control cells. Conclusion: Our results showed that, IL-27 under in vitro conditions, could potentially suppress tumor without any essential cells and biologic factors of tumor matrix. Therefore, rmIL-27 may be a probable candidate protein as an antitumor agent, applicable to breast cancer immunotherapy.

L Shokoohizadeh, A Mohabati Mobarez, Mr Zali, R Ranjbar, M Alebouyeh,
Volume 22, Issue 91 (4-2014)

Background and Objective: Vancomycin-resistant enterococci (VRE) are the major causative agents of urinary tract infections (UTIs) in hospitalized patients. The aim of this study was to determine the prevalence of urinary tract infections caused by enterococcus faecium and the level of resistance to vancomycine and other antibiotics which are effective in enterococcal infection therapy of hospitalized patients in four university teaching hospitals of Tehran. Materials and Methods: This study was carried out between September 2011 and May 2012. Urine samples were collected from hospitalized patients in Taleghani, Loghman , Mofid and Labaffi nejad Hospitals in Tehran. Enterococcus species were detected by biochemical and molecular tests. Antimicrobial susceptibility and minimum inhibitory concentration (MIC) of vancomycine were determined by disk diffusion and micro agar dilution methods. The presence of vanA and vanB genes were investigated in VRE strains by PCR. Results: 86 enterococci were isolated from urine samples of which 45(52%) were E.faecium. 42.2% of E. faecium isolates were resistant to vancomycin (VRE) and showed vanA genotype. All VRE isolates were resistant to ampicillin, gentamicin, ciprofloxacin and erythromycin, and 78% were resistant to nitrofurantoin. Furthermore, all VRE isolates were sensitive to linezolide and quiopristin-dalfopristin. MIC50 ≥ 128 and MIC90 ≥ 256 were detected in the VRE strains. Conclusion: The increase in the prevalence of vancomycin resistant E. faecium with high risk resistance profiles is a serious threat for some Iranian hospitals and limits the therapeutical options for patients infected with E. faecium.

Mm Soltan Dallal, A Rastegar Lari, R Bakhtiari, B Nikmanesh, Mk Sharifi Yazdi,
Volume 22, Issue 92 (5-2014)

Background and Objective: Attention has largely been focused on appearance of multiple drug resistance enterococci in the last 20 years. One of the methods to overcome this problem is to combine different antibiotics in order to increase antimicrobial activity and reduce toxicity. The combination of fluor quinolones with other antibiotics has been widely investigated. The aim of this study was to investigate the synergistic effect of ciprofloxacin in several antibiotics Beta-lactam (piperacillin, ceftazidime and imipenem) on isolated enterococci. Materials and Methods: In this cross sectional study, 67 Streptococci strains were isolated from clinical samples from March to September 2012. The serial broth dilution method in test tubes was used for the MIC, and the check board Format was used for the synergistic effect of ciprofloxacin with Beta-lactam antibiotics. The synergistic effect was determined with four- fold reduction of initial MIC. Results: Totally, 67 strains of Streptococci were used, in which 50 strains (74.6%) were enterococci, 6(9%) were group B streptococcus, 5(7.5%) were non-group A streptococci, 2 (3%) were pneumococci, and 2 were strains of alpha streptococci (3%), respectively. All results were determined by the MIC and MBC of each antibiotic individually and also in combination with ciprofloxacin. Conclusion: The effect of ciprofloxacin on other antibiotics was indifferent, and the synergistic effect was not observed.

E Tajeddin, M Alebouyeh, Ah Mohammad Alizadeh, Mr Zali,
Volume 22, Issue 94 (7-2014)

Background and Objective: The aim of this study was to detect bacteria associated with biliary tract diseases and relationship between their class 1, 2 and 3 integrons and antibiotic resistance patterns. Materials and Methods: Bile samples of biliary patients undergoing cholangiopancreatography were examined for the presence of bacteria and antibiotic resistance patterns using biochemical tests and disk diffusion method. PCR was used for detection of the presence of integrase genes intI1, intI2, and intI3 in total DNA and plasmid extracts of these bacterial isolates. Results: Out of 102 bile samples, 41.2% were positive by culture. The isolated bacteria belonged to E. coli (35.5%), Enterococcus spp. (19.4%), Klebsiella pneumoniae (17.74%), Pseudomonas aeruginosa (17.74%), Acinetobacter spp. (6.45%) and Staphylococcus epidermidis (1.6%). All isolates were resistant to amoxiclav and 87.5% of the isolates showed multidrug resistance (MDR) pattern. intI1and intI2 were found in E. coli (59.09%, 50%), P. aeruginosa (81.81%, 45.45%), K. pneumonia (63.6%, 27.27%) and Acinetobacter spp. (100%, 100 %), respectively. These results showed the presence of class 1 and 2 integrons on the extracted plasmids and indicated a significant association between class 1 integron and resistance to gentamicin and ciprofloxacin. Conclusion: High frequency of class 1 and 2 integrons among the bile isolates and their association with increased antimicrobial resistance phenotypes suggests that bile components are as selective agents for bacterial strains encoding these elements.

M Hassan, H Jahangiri, K Kamali , Z Hojabri ,
Volume 23, Issue 101 (8-2015)

Background and Objective: Enterococci lead to many problems in terms of treatment failure and mortality in patients especially due to antibacterial resistance. Identification of antibiotic resistance in community is of extreme importance to prevent failures particularly in the treatment of infections. Therefore, this study intended to screen antibiotic-resistant enterococci samples from patients.

Materials and Methods: Samples were collected from feces and blood of patients hospitalized over a period of 9 months from July 2013 to March 2014 in Vali-e Asr and Mousavi hospitals. Diagnostic tests such as growth in the presence of bile esculin agar and NaCl 6.5% as well as catalase and Gram staining were performed to verify the samples. Agar disk diffusion method for antibiotic susceptibility testing and microtitre plate assay was performed to evaluate the MIC of vancomycin.

Results: Among the tested antibiotics, ciprofloxacin showed the highest and teicoplanin as well as vancomycin exhibited the least antibiotic resistance. Interestingly, vancomycin minimum inhibitory concentration was determined 5 to 50 &mug/ml.

Conclusion: In our study, isolated enterococci from the hospitalized patients showed relatively high resistance to majority of antibiotics. Meanwhile, antibiotic resistance to teicoplanin and vancomycin were acceptable in comparison to other similar studies.

A Sharifi, A Mohammadzadeh, P Mahmoodi, N Sasanian,
Volume 24, Issue 105 (6-2016)

Background and Objective: Antibiotic resistant phenotypes of bacteria have been shown to be related to efflux pumps. Research for finding compounds with an ability to inhibit these pumps seems worthwhile due to their ability to increase bacterial sensitivity to antibiotics or return sensitivity to resistant strains. The aim of this study was to evaluate inhibitory effect of Thymus daenensis essential oil (EO) on NorA efflux pump of staphylococcus aureus.

Materials and Methods: Thymus daenensis essential oil was extracted from dried thyme leaves by hydrodistillation method and then the effect of the essential oil on bacterial efflux pump was evaluated using ethidium bromide-agar cartwheel method with respect to bacterial efflux capacity of ethidium bromide. Minimum inhibitory concentration (MIC) of Thymus daenensis essential oil was measured using microdilution test followed by the evaluation of the effect of sub-MIC concentration of essential oil on fluoroquinolone antibiotics. The efflux level of ethidium bromide, ciprofloxacin and norfloxacin (substances transmitted by NorA) was considered as the NorA efflux pump activity.

Results: The cartwheel method showed that Thymus daenensis essential oil could reduce the bacterial efflux capacity of ethidium bromide. The results of checkerboard test indicated that the interactions between sub-MIC concentration of the essential oil and ethidium bromide, ciprofloxacin and norfloxacin were totally synergistic.

Conclusion: Synergistic effect of Thymus daenensis essential oil with the other components demonstrated the potential of Thymus daenensis to enhance the antimicrobial activity of fluoroquinolone antibiotics against staphylococcus aureus. As these antibiotics are effluxed by NorA pump, this increased sensitivity to antibiotics is possibly due to NorA efflux pump inhibitors.

A Akya, A Elahi, R Chegeneh Lorestani, K Ghadiri,
Volume 26, Issue 115 (5-2018)

Background and Objective: One of the mechanisms involved in the resistance of Klebsiella pneumoniae to fluoroquinolones is AcrAB leakage pumps.  In this study, the prevalence of Klebsiella pneumoniae isolates with AcrAB encoding genes and the role of permeation pumps in fluoroquinolone resistance were investigated.
Materials and Methods: 165 samples from patients of Kermanshah Medical Centers were collected and 100 isolates of Klebsiella pneumoniae approved by API-20E kit. Antibiotic susceptibility of isolates to ciprofloxacin and levofloxacin was determined using disk diffusion and MIC (Minimum Inhibitory Concentration) experiments. AcrA and AcrB genes were determined by PCR method. The effect of bacterial permeation inhibitor (CCCP) Carbonyl cyanide m-chlorophynyl hydrazone with final concentration of 5μg / ml on MIC of fluoroquinolones resistant isolates was done using agar dilution method.
Results: Of the100 Klebsiella pneumoniae isolates, 28 (28%), were resistant to ciprofloxacin and levofloxacin. Both acrA and acrB genes were resistant to antibiotics in all Klebsiella pneumoniae isolates. The effect of CCCP on isolates resistant to ciprofloxacin and levofloxacin resulted in a decrease in MIC in 11 isolates (39.2%), among which the MIC was changed in five isolated from resistant to susceptible state.
Conclusion: Although the high drug resistance of isolates is not due to permeation pumps, the results of inhibition of pump indicate their role in the resistance of 39% of isolates. Also, the presence of AcrAB genes in all fluoroquinolones resistant Klebsiella pneumoniae isolates shows the importance of these pumps.


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