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Showing 21 results for Antibiotic
Mohammadreza Nahaei , Reza Bohloli Khiavi , Mohammad Asgarzadeh, Alka Hasani , Javid Sadeghi, Mohammad Akbari Dibavar ,
Volume 7, Issue 1 (4-2007)
Abstract
Background and Objectives: Pseudomonas aeruginosa is a nosocomial pathogen that presents high antibiotic resistance.There are phenotyping and genotyping methods for epidemiologic study of Pseudomonas aeruginosa such as antibiotic resistance pattern and plasmid profile analysis. Plasmid analysis provides useful information concerning the source of the strains and number of clones present in the epidemies. Thus, this study was conducted to evaluate antibiotic and plasmid profiles of P. aeruginosa strains isolated from in-patients of the Sina Medical Centre of Tabriz to clarify epidemyological correlation among isolated strains. Methods: During 13 months, 135 strains of P. aeruginosa were isolated from different infections in hospitalized patients at Sina Medical Center of Tabriz. Antibiotic susceptibility tests were performed using disc agar diffusion test. For plasmid DNA extraction and detection of open circular bands from supercoiled ones, modified alkaline lysis procedure and two dimensional electrophoresis were used, respectively. Enzymatic digestion of plasmids was carried out by EcoRI and HincII restriction enzymes. Results: Resistance rates of strains against antibacterial agents were recorded as: Aztreonam (77%), colistin (74%), ceftazidime (69%), pipracillin (67%), ofloxacin (62%), tobramycin (56%), carbenicillin (54%), gentamicin (51%), ciprofloxacin (22%), amikacin (15%), polymixin B (13%) and imipenem (2%). Plasmid profiles of our test strains revealed that only 67 strains harbored plasmid(s). Number of isolated plasmids ranged 1-6 in each strain with molecular mass of 0.5kb-21kb. When the isolated plasmids were digested using restriction endonuclease enzymes (EcoRI and HincII), in 32% of them similar digestion profiles were obtained by EcoRI indicating a unique source for them. Conclusion : Our findings suggest high antibiotic resistance and plasmid presence in P. aeruginosa strains isolated from different infections, and there were remarkable similarities among isolated plasmids. Since our test strains had been isolated from various wards in a short period of time, the results raise the possibility of unique source for some strains or high prevalence of genetic exchange among P. aeruginosa strains.
Hadi Peeridoghaheh, Marziyeh Aligholi, Mohammadhosein Dehghan, Parviz Maleknejad,
Volume 8, Issue 1 (4-2008)
Abstract
Background & Objective: Brucellosis is one of the most common zoonotic diseases in Iran and is endemic in all parts of the country. Patients recorded in 1988 were 71,051(132. 4 per 100,000). Brucella species are facultative intracellular bacteria, and therefore a limited number of antibiotics are effective against these organisms. The aim of this study was the
evaluation of in vitro sensitivity of various antimicrobial agents against 47 brucella melitensis strains isolated from blood culture.
Methods: The susceptibility of 47 Brucella melitensis isolates derived from clinical samples were tested in vitro. The minimum inhibitory concentrations (MICs) of the tested antimicrobials were measured by the agar dilution method.MIC90 and MIC50 values were defined as the lowest concentration of the antibiotic at which 90 and 50 percent of the isolates
were inhibited, respectively. The NCCLS criteria for slow growing bacteria were considered to interpret the results.
Results: Tetracycline (MIC50: 0.13μg/ml, MIC90: 0.25 μg/ml) and streptomycin (MIC50:0.003 μg/ml, MIC90:0.25 μg/ml) had the lowest MICs in vitro against the B. melitensis strains. Norfloxacin had the highest (8 μg/ml) MIC90 value. More than half
isolates presented reduced susceptibility to rifampin (MIC value: 2μg/ml).
Conclusion: Brucella isolates remain susceptible in vitro to most antibiotics used for treatment of brucellosis. There is no significantly important resistance problem for antibiotics targeted against Brucella species in Iran. However, since rifampin is commonly used for prevalent diseases such as tuberculosis, the regional susceptibility pattern of rifampin should be assessed periodically.
Abbasali Imani Foolad , Zahra Rostami , Reza Shapouri,
Volume 10, Issue 3 (9-2010)
Abstract
Background and Objectives: Detection of TEM and SHV genes in ESBL producing Pseudomonas aeruginosa and their antimicrobial resistance pattern can provide useful information about the epidemiology and risk factors of associated infections. In this study we determined the antimicrobial susceptibility pattern and prevalence of ESBLs in clinical isolates of Pseudomonas aeruginosa by phenotypic and genotypic methods. Methods: In this analytic-descriptive study, 110 Pseudomonas aeruginosa strains isolated from different clinical specimens were used. The pattern of antimicrobial resistance was determined by disk diffusion (Kirby-buer) method. The ESBL production was determined by combination disk method using disks containing ceftazidim and cefotaxim alone and in combination with Clavulanic acid. SHV and TEM types of ESBL producing genes was detected by PCR. Results: In this study Co-trimoxazole and Amoxicilin with 96.4% and 92.7% and Amikacin with 17.3% showed the highest and lowest resistance against isolates respectively. According to PCR results 37.5% and 12.5% of isolate were carried SHV and TEM genes respectively and 12.5% of isolate were carried both the SHV and TEM genes. Conclusion: According to the results most of the isolates are drug resistant and among the ESBL producing strains the frequency of SHV type is higher than TEM . The isolate ceftazidim resistance was contains SHV (37.5%) and TEM gene (12.5%), that showed SHV and TEM genes play more important role in create of ceftazidim resistance than cefotaxim resistance.
Abbasali Imani Foolad, Maryam Hosainzadeh, Seiyed Fazlollah Mousavi ,
Volume 11, Issue 1 (4-2011)
Abstract
Background & Objectives: Pseudomonas aeruginosa is a Gram-negative and aerobic bacterium. Exotoxin A is one of the important toxins produced by the bacterium and it is the main cause of mortality. About 90% of P. aeruginosa strains produce this toxin. Biofilm is a functional consortium of microorganisms attached to the body surfaces and bacteria are embedded in extracellular polymeric substances produced by the microorganisms. This bacterium is nontoxic in the planktonic form, but as a biofilm is highly toxic. In this study, we examined the association between the presence of exo-A gene and antibiotic resistance patterns with biofilm formation in Pseudomonas aeruginosa strains. Methods: In this study 110 strains of Pseudomonas aeruginosa isolated from various infections with defined antibiotic resistance patterns were used. The PCR method was used to detect the presence or absence of Exotoxin A gene (exo-A). Ability of biofilm formation was evaluated by spectrophotometry. Association between exo-A gene and antibiotic resistance patterns with biofilms formation was analyzed statistically by Fishers and Chi-square tests. Results: exo-A gene was detected in 93 strains (84.5%). Sixty two strains were multidrug resistant and they produced broad spectrum beta-lactamase enzyme. Results showed that, exo-A positive strains had significantly higher ability to biofilm formation in comparison with exo-A negative strains (p<0.05). Also the biofilm formation was significantly higher in multidrug resistant and ESBL producing strains (p<0.05). Conclusion: The results of this study indicate that there is a significant association between exo-A gene as well as antibiotic resistance pattern and ESBl producing with biofilm formation in Pseudomonas aeruginosa. Because of importance of biofilms in the pathogenesis of this bacterium, our study could open a new window for investigation of the molecular processes involved in the formation of biofilms.
Parviz Mohajeri , Babak Izadi , Mansour Rezai , Badie Falahi , Hosna Khademi , Roya Ebrahimi ,
Volume 11, Issue 1 (4-2011)
Abstract
Background & Objectives: Nowadays, appearance of ESBL producing bacteria is medical problem in the treatment of infections. Uropathogenic Escherichia coli like many other bacteria can produce these types of enzymes. T he assessment of the ESBL production by clinical isolates is not done routinely in laboratories. The aim of this study was to determine the prevalence of ESBL producing E.coli and its antibiotic resistance pattern in Kermanshah. Methods: This cross - sectional study was done on 200 Uropathogenic E. coli strains isolated from people in Kermanshah. Sensitivity of isolates to different antibiotics was determined by disk diffusion test and ESBL production was assessed by DDST method. Results: The E. coli strains showed high susceptibility to imipenem (100%), amikacin (97%), nitrofurantoin (95.5%), gentamicin (85%), cefepime (75%), ceftazidime (74%), ofloxacin (73.5%), ciprofloxacin, ceftriaxone and aztreonam (71%) and cefotaxime (70%) respectively. The highest resistance was seen to ampicillin (77%), carbenicillin (76%), pipracillin (74%) and SXT (62.5% ). Resistance rate to third generation cephalosporins was 63-75%. Fifty seven isolates (27%) were ESBL producers and 47 isolates (87%) produced all four types of ESBL enzymes. Conclusion: There are some similarities and differences in the antibiotic resistance pattern and ESBL production among the isolates in different areas of Iran and other countries. Identification of ESBL producing bacteria and determining its antimicrobial resistance pattern are recommended to effective treatment of infections.
Shahram Abdoli Oskouie, Mohammad Ahangarzadeh Rezaee , Ali Ajhangh , Babak Abdinia,
Volume 13, Issue 1 (4-2013)
Abstract
Background & Objectives: Staphylococci are among common causes of community acquired and nosocomial infections around the world. Over the last decade, the resistance of these bacteria in hospital environments is increasing to various antibiotics such as vancomycin. The aim of present study was to determine the antimicrobial resistance pattern and Minimum Inhibitory Concentration (MIC) values among a clinical collection of staphylococci isolated from hospitalized children in Tabriz. Methods: In this prospective and descriptive study, 88 staphylococcal isolates including 53 S. aureus and 35 coagulase-negative staphylococcus species were recovered from various clinical specimens referred to microbiology laboratory of Children Hospital during study period (April 2011 to March 2012). Susceptibility of the isolates against 15 different antimicrobial agents and MIC values of vancomycin was tested using standard disk diffusion and E-test methods respectively. Results: According to the results of drug susceptibility testing, vancomycin and rifampin were the most effective but clindamycin and penicillin were the least effective drugs against tested isolates. Accordingly, the prevalence of methicillin resistant Staphylococcus aureus (MRSA) strains was determined more than 80%. According to MIC values, 13.2% of S. aureus and 3.3% of coagulase-negative staphylococcus isolates showed intermediate resistance to vancomycin. None of the isolates was fully resistant to vancomycin isolates in this study. Conclusion: Although fully vancomycin resistant staphylococci was not found among tested isolates in this study, there was VISA strains. Since there are reports on the emergence of VRSA strains from Iran and other countries, it is necessary for the clinician to care in prescription of vancomycin as a selective drug against staphylococcal infections. Moreover, the necessity of MIC measurement in determining of vancomycin susceptibility is more apparent.
Delsuz Rezaee , Gholamreza Zarrini , Mohammad Ahangarzadeh Rezaee,
Volume 14, Issue 1 (4-2014)
Abstract
Background & Objectives : Acinetobacter baumannii is an opportunistic Gram-negative pathogen with increasing relevance in a variety of hospital-acquired infections especially among intensive care unit patients. A. baumannii is mostly a cause of septicemia, pneumonia and urinary tract infection following hospitalization of patients. In this study antibiotic susceptibility pattern of A.baumannii isolates and molecular typing among isolates resistant by REP-PCR were determined. Methods : During study, the A. baumannii, were isolated from hospitals in Tehran. The isolates were identified using standard biochemical tests and antibiotic susceptibility was determined by the disk diffusion method. Extraction of DNA and molecular typing of isolates performed using CTAB method and REP-PCR, respectively. Results : In this study 75 A. baumannii isolates separated from patients with an average age of 51 ± 18.45 years . The highest resistance rate was against azteronam (97%), ceftazidim (93%), cefepime (93%), piperacillin-tazobactam (93%), ciprofloxacin (93%) and ticarcillin (93%) while the lowest resistance rate was against tigecycline (n= 51, 68%), followed by tobramycin (n=24, 32%), ampicillin-sulbactam (n=21, 28%), amikacin (n=16, 21%), and carbapenems (n=11, 15%). The REP-PCR in resistant of A. baumannii isolates showed that the genotypes of A, B and C are the predominant genotypes in the resistant antibiotics. Conclusion: This study showed a high percentage of resistance to antimicrobial agents among genotypes A, B, and C of the A. baumannii isolates therefore strategies to control the spread of A. baumannii isolates must be designed and evaluated.
Maryam Adabi, Mahshid Talebi Taher , Leila Arbabi, Mastaneh Afshar , Sara Fathizadeh, Sara Minaeian, Niloofar Moghadam-Marageh, Ali Majidpour ,
Volume 15, Issue 1 (4-2015)
Abstract
Background & objectives: Wound infection is a predominant cause of death in burned patients who are clearly at increased risk of nosocomial infections. Pseudomonas aeruginosa is the most common cause of burn infections and is difficult to treat because of having high level of resistance to antibiotics. The aim of this study was to perform isolation, identification and determination of antibiotics resistance pattern of P. aeruginosa strains isolated from wounds of hospitalized burn patient.
Methods: Biochemical and molecular tests were used for identification of the P. aeruginosa and antibacterial susceptibility test was performed using disk diffusion (Kirby- Bauer) methods. Then, the minimum inhibitory concentration (MIC) was performed for four representatives of different groups of antibiotics.
Results: Among 94 evaluated strains of P. aeruginosa, 83 isolates (88.3%) were multi drugs resistant. Based on Kirby-Bauer method, the most resistance was seen to cefepime (89.5 %) and among the antibiotics studied to determine the MIC, the most resistance was observed to ciprofloxacin (89 %).
Conclusion: These results indicate high range of resistance to different antibiotics among strains of P. aeruginosa isolated from burn wounds of patients. So, the fast and accurate measurement and evaluation of antibiotic resistance for appropriate antibiotic therapy of burned patients is imperative.
E Raeisi, M Ghiamirad,
Volume 15, Issue 3 (10-2015)
Abstract
Background & Objectives: Salmonellosis is the most common food-borne disease in the world. The purpose of this study was to determine the prevalence of salmonella serogroups and their antimicrobial susceptibility patterns in chicken meat and viscera in Ardabil, Iran.
Methods: In this cross-sectional study done in spring and summer of 2014,260 samples) 160 chicken meat, 50 gizzard and liver) were collected for isolation and identification of salmonella. The technique used in this study was recommended by Iran standard organization andKirby-bauer method was also used for detection of antibiotic resistance.
Results: Amongallthe samples,the range of detected salmonella was 10%I n which the 42.3% of them detected in spring and 57.7% in the summer.92.3% of samples belong to C serogroup and 3.8% of them were serogroup B and 3.8% serogroup D. All isolates show resistance to at least two antibiotics. Concurrent resistance to 2-6 antibiotics was detected in 70% of the isolates. The highest resistance was to Nalidixicacid�and Streptomycin (100%)and toTetracyclin (92.3%), Penicillin (88.5%), Neomycin, Kanamycin and Furazolidon (84.6%), cloramfenicol (73.1%), Ofloxacin (15.4%), Co-Amoxi clave and Ampicillin (11.5%) and Siprophloxacin 7.7%. The lowest levels of resistance were for Gentamycin and Amikacin (3.8%). No salmonella isolates were resistant to ceftazidime, Azitromicin, Meropenem, Imipenem and cefixime.
Conclusion: According to 10% pollution to salmonella and prevalence of serogroup C and salmonella importance in the human&rsquos health, as well as high rate of antibiotic resistance of isolates, applying a health strategy for reduction of contamination level is necessary.
Roqiyeh Nouri, Mohammad Ahangarzadeh Rezaee , Alka Hasani, Mohammad Aghazadeh, Mohammad Asgharzadeh, Morteza Ghojazadeh,
Volume 16, Issue 2 (7-2016)
Abstract
Background & objectives: Fluoroquinolones have important role in treatment of P. aeruginosa infections. The main mechanism of fluoroquinolones resistance in P. aeruginosa is mutations in the quinolone-resistance-determining region (QRDR) of gyrA and parC genes. The aim of this study was to investigate the role of these mutations in ciprofloxacin resistance in different clinical isolates of P. aeruginosa.
Methods: A total of 75 clinical P. aeruginosa isolates were collected from different university-affiliated hospitals in Tabriz. Minimum inhibitory concentrations (MICs) of ciprofloxacin were evaluated by Etest assay. DNA sequences of the QRDR of gyrA and parC were determined by dideoxy chain termination method.
Results: From 75 isolates, 77.33% were resistant to ciprofloxacin. No amino acid changes were detected in gyrA or parC genes of the ciprofloxacin susceptible isolates. Thr-83→Ile substitution in gyrA was observed in all ciprofloxacin resistant isolates. About 90% of them had Ser-87→Leu substitution in parC. Geometric mean MICs of ciprofloxacin were different for various clinical isolates of P. aeruginosa which had the same situation in type and location of gyrA and parC mutations. Moreover, the geometric mean MIC in isolates from urine was significantly (p<0.05) higher than isolates from tracheal aspirates.
Conclusion: Mutations in gyrA and parC genes are the major mechanisms for ciprofloxacin resistance in clinical isolates of P. aeruginosa. Moreover, the role of different effective factors in fluoroquinolone resistance can be different in various clinical isolates of P. aeruginosa.
Faramarz Hosseinzadeh, Saeid Sadeghieh Ahari , Ali Mohammadian-Erdi ,
Volume 16, Issue 2 (7-2016)
Abstract
Background & objectives: One of the most proven trajectories for analyzing the drug consumption patterns in the community is to assess the prescriptions. Using the antibiotics for prevention and treatment of infectious diseases not only leads to the loss of pathogens but also causes various complications, the most important of which is the drug resistance. The aim of current study was investigating the different antibiotics prescript by general practitioners (GPs) for outpatients in Ardabil city.
Methods: This study is designed based on the cross-sectional method. The number of 2,000 copies (according to Morgan) from total of 526000 copies sent to Ardabil health insurance during the 4 seasons of 2013 were randomly evaluated. The collected data were analyzed by descriptive statistics, ANOVA and T-Test using spss software. The P ≤0.05 was considered statistically significant.
Results: In this study the average drug per prescription was 3.6 and 54.9% of the prescriptions included antibiotics so that the cefixime, azithromycin, Co-amoxiclave and penicillin 6.3.3 were the most frequently prescribed antibiotics, respectively. The highest prescriptions belonged to penicillins (39.4%) cephalosporins (27.7%) and macrolides (18.3%). The most expensive antibiotic was cefixime tablet (32% of the total cost). The most of the antibiotics were prescribed to be taken orally (tablets or capsules). The mean price of each prescription was 74539±71050 Rials. The highest rate of antibiotic prescription was related to the autumn and then winter and there was a significant relationship between the the number of antibiotics in different seasons of the year (p = 0.005).
Conclusion: The average drugs of each prescription are in accordance with local statistics, but much higher than the global figures. The frequency of antibiotics prescription was higher than the global, several Middle Eastern and even African countries’ indices but was lower than the average level of some regions in the country. The pattern of prescribing antibiotics among the Ardabil GPs shows the more drugs in number and expensive broad-spectrum. The average price of prescripts was higher than the national average. These findings suggest that prescription and using antibiotics is not desirable in Ardabil.
Hosseini Fatemeh, Mohammad Kargar,
Volume 17, Issue 2 (7-2017)
Abstract
Background & objectives: Enterococcus spp. are predominant in the faecal microflora which enter the environment directly or through wastewater. These bacteria play an important role in the development of nosocomial infections due to their ability to acquire resistance genes and their transmission to other bacteria, particularly Staphylococcus aureus. The aim of this study was to identify the prevalence of vancomycin-resistant enterococci (VRE) and to detect van A, van B and van C1/C2 genes in VRE strain isolated from environmental samples of the in southern Fars province.
Methods: This cross-sectional study was carried out on 155 Enterococcus spp isolates collected from environmental samples (hospital wastewaters and surface waters) in different areas of Larestan and Jahrom cities. Isolates were identified and confirmed as Enterococcus spp. using the membrane filtration method, selective growth on Kenner Fecal Streptococcus Agar (KF) medium and biochemical tests. The disk diffusion test and Macro Broth dilution method based on CLSI guidelines were used to determine antimicrobial susceptibility against conventional antibiotics and vancomycin and to measure the minimum inhibitory concentration (MIC), respectively. Finally, the presence of van A, van B and van C1/C2 genes in VRE strains was determined by multiplex PCR technique.
Results: Out of all of Enterococcus spp. isolates, 41 cases (26.45%) were belonged to E.faecalis, 6 cases (3.87%) to E.faecium and 108 cases (69.68%) to non-faecalis and non-faecium. In total, 46 isolates (29.67%) were resistant to vancomycin and 4 isolates showed MIC ≥128 μg/ml. Resistant to all types of antibiotics was observed in 4 isolates (8.70%). Further, 2 isolates (50%) had vanA gene and 2 isolates (50%) had vanB gene, but vanC1/C2 genes were detected in none of them.
Conclusion: The results indicated that the VRE strains are widespread in the studied area, therefore there is an urgent need for prudent use of vancomycin and implementation of control measures to prevent the environmental spread of VRE strains.
Hoosna Sarvazad, Mojtaba Darbouy,
Volume 17, Issue 3 (10-2017)
Abstract
Background & objectives: One of the main problems in the control of nosocomial infections due to Klebsiella pneumoniae is increase of antimicrobial resistance and prevalence of extended spectrum β-lactamase (ESBLs) producing isolates. The aim of this study was to investigate the correlation of antibiotics resistance with SHV, CTX-M and TEM extended-spectrum beta lactamases genes among Klebsiella pneumoniae isolates isolated from the patients in Kermanshah hospital.
Methods: The clinical isolates of Klebsiella pneumoniae were collected during the spring from Kermanshah hospitals, and identification of Klebsiella pneumoniae strains was performed using standard microbiological and biochemical tests. Antibiotic resistance of Klebsiella pneumoniae isolates was determined using disk diffusion method. Then, the presence of CTX-M, SHV, and TEM was investigated using multiplex-PCR method. Finally, the relationship between variables was analyzed by SPSS-22 software using logistic regression and chi-square.
Results: A total of 98 isolates out of 112 samples were identified as Klebsiella pneumonia. Also, 82.8% of isolates were resistant to cefotaxime, 40.2% to ceftriaxone, 62.88% to ceftazidime, 3.9% to imipenem, 39.17% to cefepime, 64.94% to cefixime and 26.8% to amikacin. Further, 35.55% of isolates had CTX-M gene, 63.91% of isolates had SHV gene and 9.27% of samples had TEM gene.
Conclusion: The presence of CTX-M, SHV and TEM genes along with high antibiotic resistance are very concerning, indicating the importance of rational use of antibiotic for the treatment of infectious diseases.
Atefe Sarafan Sadeghi , Najmeh Ansari, Farzad Khademi, Reza Mir Nejad , Behnam Zamanzad ,
Volume 19, Issue 1 (4-2019)
Abstract
Background & objectives: In recent years, Acinetobacter baumannii has been shown to be associated with several nosocomial infections, including pneumonia, bacteraemia, urinary tract infections, wound infection and meningitis. This organism can survive in the hospital environment and rapidly develops resistance to many antibiotics. The molecular genotyping can increase our knowledge about the spread of A. baumannii strains from one hospital to another and their drug resistance. Therefore, this study aimed to determine the prevalence of antibiotic resistance profile as well as phylogenetic relationships of A. baumannii strains in Shahrekord teaching hospitals.
Methods: In this study, antibacterial susceptibility patterns of A. baumannii strains isolated from different clinical specimens (urine, blood, sputum) to amikacin, ampicillin/sulbactam, aztreonam, cefepime, ceftazidime, ciprofloxacin, gentamycin, imipenem, meropenem, norfloxacin, ofloxacin, piperacillin/tazobactam, tobramycin were tested using disk diffusion )Kirby-Bauer( method. Finally, genotyping of A. baumannii strains was performed using REP-PCR method.
Results: During this study, 50 samples of patients were identified as A. baumannii) 71%(, and their drug resistance rates were assessed. All A. baumannii strains were resistant to ceftazidime and cefepime and also a high rate of resistance to aztreonam, norfloxacin, ciprofloxacin, amikacin, imipenem, gentamycin, and ampicillin-sulbactam were observed. On the other hand, our results demonstrated nine genotype groups among A. baumannii strains based on REP-PCR method.
Conclusion: Due to the high prevalence of antibiotic resistance among isolated A. baumannii strains, similarities between different genotypes and the dispersion of these genotypes in different parts of Shahrekord hospitals, the implementation of infection control programs in different parts of the hospital is necessary.
Roghieh Saboorian, Mohammad Rahbar, Marjan Rahnamaye Farzami , Parvaneh Saffarian,
Volume 19, Issue 2 (7-2019)
Abstract
Background & objectives: Antibiotic resistance in Vibrio cholerae is a crucial matter in the world. Objective of this study was the improvement of cholera surveillance by assessing the antimicrobial resistance pattern and bacterial resistance genes in V. cholerae O1 isolates, reffered to Iranian Reference Health Laboratory, in cholera outbreaks during 2012- 2015.
Methods: This study is a cross sectional- descriptive research. Antimicrobial susceptibility test (AST) to 8 antibiotics was performed on 113 V.cholerae O1 isolates using E-test method. For all isolates, conventional PCR method was used to detect the presence of tetracycline resistance genes (tetA, tetB and tetC) and the sulfamethoxazole-trimethoprim resistance genes (sul2 and dfrA1).
Results: All isolates were sensitive to ampicillin, temocillin, ciprofloxacin and cefixime and 64% of strains showed intermediate susceptibility to erythromycin. The resistance rate of nalidixic acid, sulfamethoxazole-trimethoprim and tetracycline were 90%, 71% and 50% respectively. However, the frequency of multidrug resistant (MDR) strains varied across the years. The frequency of resistance genes (tetA, tetB, tetC, sul2 and dfrA1) were 70%, 34%, 58%, 66% and 70% respectively.
Conclusion: AST should be used to determine the resistance profile at the beginning of a cholera outbreak and to monitor the resistance profile of circulating strains as part of surveillance of the disease. A prominent association was observed between phenotypic resistance to sulfamethoxazole-trimethoprim and presence of dfrA1gene. Determining the presence of resistance genes is necessary for understanding the epidemiology and routes of transmission of antibiotic resistance genes
Lida Jalali Dizage, Mohammad Reza Nahaei, Javid Sadegi,
Volume 19, Issue 3 (10-2019)
Abstract
Background & objectives: Urinary tract infection (UTI) is one of the most common types of human infections and Escherichia coli and Klebsiella pneumonia are the main causes of urinary tract infection among the gram negative bacteria. The prevalence of extended-spectrum β-lactamases (ESBLs) among these bacteria and hence resistant strains to β-lactam antibiotics have increased in recent decades. Several types of extended-spectrum β-lactamases, such as TEM, SHV and CTX-M have been identified, which are prominently present in the strains of E. coli and K. pneumoniae. The objective of this study was to determine the prevalence of TEM and SHV genes in E. coli and K. pneumoniae isolates of urinary tract infections by using phenotypic and molecular (PCR) techniques in microbiology laboratory at medical school of Tabriz Islamic Azad University.
Methods: In this cross-sectional descriptive study, 50 isolates of E. coli and 50 isolates of K. pneumoniae collected from urinary tract infections from out-patients in Tabriz. Antibiotic sensitivity patterns of isolates were studied against 14 antibiotics by disk diffusion test (Kirby Bauer) and also confirmatory tests were performed using combined antibiotic tests. Finally TEM and SHV genes were investigated using molecular methods (PCR).
Results: Twenty five isolates (25%) out of 100 bacterial isolates were identified as ESBL-producing isolates of which 13 isolates (26%) were E. coli and 12 isolates (24%) were K. pneumoniae. The TEM and SHV genes were detected in 2% and 4% of E.coli and 0% and 2% of K. pneumoniae isolates, respectively.
Conclusion: The presence of these genes among our isolates confirmed ESBL genes in these medically important bacteria leading to resistance against β-lactam antibiotics which are routinely used in their treatments. The low frequency of the studied genes could be because of the source of our isolates from out-patients which are not generally exposed to antibiotics
Sanaz Habibi, Roya Safarkar, Vahid Rouhi,
Volume 19, Issue 4 (1-2019)
Abstract
Background & objectives: Methicillin-resistant Staphylococcus aureus is one of the most common causes of nosocomial infections. The polysaccharide adhesion mechanism encoded by the ica operon generates a direct role in biofilm formation and infection of the bacteria. The aim of this study was to evaluate the frequency of icaA gene in Staphylococcus aureus isolates isolated from clinical specimens of patients admitted to some clinical centers of Rasht.
Methods: This descriptive, cross-sectional study was performed on 100 Staphylococcus aureus isolates from some clinical centers of Rasht in 2019 and confirmatory tests were performed to identify the bacteria. icaA gene identification and its frequency were investigated using molecular methods . The antibiotic resistance pattern against 10 antibiotics and biofilm-forming ability of the isolates were determined using the disk diffusion method and Congo red method respectively.
Results: In the present study, among the 100 studied isolates, the highest drug resistance was related to penicillin, and the lowest antibiotic resistance was belonged to ciprofloxacin. 81 isolates (81%) were resistant to methicillin and 37 isolates (37%) had multiple resistance. Of 37 isolates with multiple resistances, 32 isolates (86.48%) had icaA gene and 24 isolates (64.9%) ،had the ability to produce strong biofilms.
Conclusion: According to the findings of this study, the prevalence of Staphylococcus aureus isolates carrying icaA gene with strong biofilm forming ability and resistance to methicillin, were high. This necessitates the need for serious management of antibiotic administration.
Seyed Ali Bazghandi , Somayeh Safarirad, Mohsen Arzanlou, Hadi Peeri-Dogaheh , Hossein Ali-Mohammadi , Farzad Khademi,
Volume 20, Issue 2 (7-2020)
Abstract
Background & objectives: Bacterial antibiotic resistance is becoming a global health crisis. The aim of this descriptive, cross-sectional study was to investigate the prevalence of multidrug-resistant Pseudomonas aeruginosa strains in Ardabil.
Methods: During 9 months, between July 2019 and March 2020, 50 strains of Pseudomonas aeruginosa were collected from different clinical specimens in four hospitals of Ardabil and the prevalence of MDR, XDR and PDR strains of Pseudomonas aeruginosa were evaluated. Antibiotic susceptibility testing was assessed using the disk diffusion method.
Results: In the present study, the prevalence of MDR, XDR and PDR strains of Pseudomonas aeruginosa were 52%, 40% and 14%, respectively.
Conclusion: Due to high prevalence of multidrug-resistant strains of Pseudomonas aeruginosa in Ardabil, continuous monitoring of the antibiotic resistance trend in clinical isolates in order to select the best medication is necessary.
Khadijeh Hamidian, Elyas Abdollahi, Zahra Yazdanpour, Laleh Shahrakimojahed, Farzad Khademi, Hamid Vaez,
Volume 21, Issue 1 (4-2021)
Abstract
Background and objectives: Urinary tract infection (UTI) is the most prevalent infection and Escherichia coli (E. coli) is one of the main causes of UTI worldwide. Integrons are mobile genetic elements considered to be responsible for dissemination of multi-drug resistance infections. Therefore, the aims of this study were to investigate the antibiotic resistance patterns and distribution of class I, II and III integrons among E. coli isolated from patients.
Methods: In this descriptive cross-sectional study, from Jun 2020 to March 2021, in total, 70 non-duplicate strains of E. coli were isolated from patients with UTI referred to Amiralmomenin hospital, Zabol, Iran. Antibiotic resistance patterns were determined using Kirby-Bauer’s disk diffusion method and Clinical and Laboratory Standards Institute (CLSI) guidelines. Class I, II and III integrons were detected using polymerase chain reaction (PCR).
Results: The isolates showed high resistance toward ampicillin (77.1%), trimethoprim- sulfamethoxazole (58.5%) and ceftriaxone (35%), whereas were mostly susceptible to meropenem (97%). Based on results of PCR, 34 (48.6%) and 3 (4.3%) isolates were classified as class I and class II integron-positive strains, respectively.
Conclusion: Resistance rate to ampicillin, ceftriaxone and trimethoprim-sulfamethoxazole was at a high level and their prescription should be restricted. Class I integron is widely distributed among E. coli isolates and play a crucial role in the emergence of antibiotic resistance
Mehrnoosh Kaviani, Mouhamad Hassan Pourrashid, Saeedeh Galledar,
Volume 24, Issue 2 (7-2024)
Abstract
Background: Antibiotics are commonly prescribed drugs by dentists. Irrational use of these drugs can lead to unwanted drug side effects, such as drug resistance in addition to unnecessary costs. This research was conducted to determine the antibiotic prescription pattern by dentists of Ardabil City based on the international ATC/DDD system.
Methods: In this cross-sectional descriptive study, 250 prescriptions of patients referred to dentists in Ardabil during the second quarter of 2021 were examined. The information related to prescribed drugs includes: drug dose, frequency of drug use, number of drugs that were collected and completed in the dental offices and clinics of Ardabil city, and finally after converting the data into a certain daily dose based on the ATC-DDD system, acquired data was analyzed using One-way analysis of variance and Tukey's post hoc tests and SPSS version 21 software, the significance level was considered less than 0.05.
Results: Out of the total 250 reviewed prescriptions, 207 prescriptions (82.8%) contained antibiotics. Metronidazole (73.4%) and amoxicillin (70.5%), were the most antibiotic drugs prescribed by Ardabil dentists respectively. In all prescribed drugs, the DDD value was higher than the standard DDD value. There was no significant difference between men and women in terms of the number of copies (p<0.05). The highest frequency was related to the prescription of three drugs and the lowest frequency was related to the prescription of six drugs. In terms of pharmaceutical forms, 201 prescriptions (97.1%) were only oral drugs and 6 (2.9%) were both oral and injectable
Conclusion: The results showed that the amount of antibiotics prescribed in prescriptions was higher than the standard DDD and the number of drugs prescribed in prescriptions was also higher than the figure recommended by the World Health Organization.
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