Showing 12 results for Drug Resistance
Mirsalehian A, Akbari Nakhjavani F, Bahador A, Jabal Ameli F, Bigverdi R, Goli H,
Volume 68, Issue 10 (1-2011)
Abstract
Background: Pseudomonas aeruginosa is an important opportunistic pathogen causes clinical infections among
burn patients. Metallo-β-lactamases (MBLs) are important mechanisms of Carbapenem (drug of choice) resistance among Pseudomonas
aeruginosa isolates. The aims of this study were to determine the
antibiotic susceptibility pattern and to detect the prevalence of MBLs among Pseudomonas
aeruginosa
Methods: Initially, the antibiotic resistance patterns of 170 clinical
strains isolated from burn patients in Motahari
Hospital in Tehran, Iran
were determined by Kirby-Bauer disc diffusion method. All of the clinical isolates using two phenotypic and genotypic methods. Pseudomonas
aeruginosa isolates resistant to Imipenem were screened for production of MBL by E test with
Imipenem / Imipenem plus EDTA (E test MBL). PCR assay was performed for detection of blaVIM genes.
Results: Based on the study results, the percentage of
resistance was as below: Imipenem (10 μg) 52.9%, Amikacin (30 μg) 81.7%, Carbenicilin (100 μg) 74.7%, Polymixine B (300 unit) 10%, Ticarcilin (75 μg) 84.7%, Tobramycin (10 μg) 88.2%, Colisitin (10 μg) 34.1, Colisitin (25 μg) 28.3%. Of 90 Carbapenem resistant isolates, 10(11/1%)
isolates were positive by E test, all were sensitive to Colisitin and Polymixine B. All of the
Imipenem resistant Pseudomonas aeruginosa isolates were examined by PCR for the
presence of the blaVIM genes. All MBL-producing isolates carried blaVIM-1 genes.
Conclusion:
Considering the high prevalence and clinical importance of MBL-producing isolates,
rapid identification of them and use of the appropriate infection control
measures are necessary to prevent further spread of infections by these
organisms.
Hashemi Sj, Zaini F, Daie R, Zibafar E, Zakeri Ma,
Volume 69, Issue 2 (5-2011)
Abstract
Background: Different studies have shown that despite the expanding number of antifungal agents, death rate caused by Aspergillus species has been increased during the recent decades due to drug-resistance occurrence, increased minimum inhibitory concentration (MIC) and cross-resistance among the isolated species. Regarding the lack of effective response to conventional treatments and antifungal susceptibility patterns of the most common isolated Aspergillus species, this study was undertaken to draw a clearer picture in the Iranian setting.
Methods: During 13 months from September 2009 to October 2010, 50 clinically isolated Aspergillus cases were identified based on the method described by Klich (2002) and their morphological features. Subsequently, their susceptibility test was carried out according to NCCLS- M38A broth microdilution method.
Results: We found that 7.5% of the isolated A. flavus with an MIC>2 µg/ml to amphotericin B were probably clinically resistant types, and 25% of them with an
MIC<8 µg/ml to itraconazole were less sensitive isolated species. The isolates were less
sensitive to voriconazole too. The MIC range of 9 strains of A. niger and the MIC of one strain of A. fumigatus had increased to all the three medications in comparison with similar foreign studies.
Conclusion: In this study we found that the MICs of most isolates were in the range of the reference strains and the MICs of some isolates were in the range of similar foreign studies. In some significant cases, the MICs were beyond the known ranges showing the lower sensitivity of Iranian isolates and their increased MIC patterns.
Katiraee F, Khosravi Ar, Khalaj V, Hajiabdolbaghi M, Khaksar Aa, Rasoulinejad M,
Volume 70, Issue 2 (5-2012)
Abstract
Background: Oropharyngeal candidiasis and antifungal drug resistance are major problems in HIV positive patients. The increased reports of antifungal resistance and expanding therapeutic options prompted the determination of antifungal susceptibility profile of Candida species isolates in Iranian patients living with HIV/AIDS (PLWHA) in the present study.
Methods: One hundred fifty oral samples from Iranian HIV positive patients were obtained and cultured on CHROMagar and Sabouraud's dextrose agar. All isolates were identified according to assimilation profile, germ tube, colony color and other conventional methods. Disk diffusion testing and Broth Microdilution of six antifungal agents were performed according to the methods described in CLSI.
Results: Candida albicans (50.2%) was the most frequent isolated yeast, followed by C. glabrata (22%). Non-Candida albicans species were isolated from 71 (61%) positive cultures. 25.7% of Candida albicans isolates were resistant to fluconazole (MIC≥64 µg/ml) as were 21.9% and 16.4% to ketoconazole and clotrimazole (MIC>0.125 µg/ml), respectively. Resistance to polyene antifungals including amphotericin B and nystatin, and caspofungin were scarce. 57.7% of candida glabrata isolates were resistant to fluconazole, 31% to ketoconazole and 35% to clotrimazole.
Conclusion: Screening for antifungal resistant candida isolates by disk diffusion or broth dilution methods in clinical laboratories is an ideal surveillance measure in the management of oral thrush in patients with HIV/AIDS. Although nystatin is widely used in clinical practice for HIV positive patients, there was no evidence of enhanced resistance to it. Regarding no resistance to caspofungin, its administration is suggested.
Peymaneh Alizadeh Taheri, Fariba Bahmani , Mamak Shariat ,
Volume 71, Issue 5 (8-2013)
Abstract
Background: One of the most common infections in neonatal period is ophthalmia neo-natorum. In this study, the bacterial agents, drug resistance and susceptibility of bacteri-al agents were studied.
Methods: In this study a total of 72 newborns with ophthalmia neonatorum admitted in Bahrami Hospital in Tehran during the years 2008-2011 were continuously enrolled in a case series, descriptive study. Demographic data, including age, sex, cause of admis-sion and culture of discharge from the eyes and its antibiogram, as well as experimental treatments and treatment outcomes were collected.
Results: Forty four infants (61.1%) were males and 28 (38.9%) were females and the mean age on admission was 11.6±7.7 days. In 51 patients (70.8%) the onset of ophthal-mia neonatorum was prior to admission. More than 56% of cases with ophthalmia neonatorum were associated with sepsis. On the other hand, positive blood culture was detected in 15.3% of cases. Among 72 neonates with ophthalmia neonatorum, 26 (36.1%) had a positive culture of the eye discharge. The most common causes of bacterial agents were Staphylococcus aureus (46.1%) (12 of 26 cases). Other causes included streptococcus species (23%), Pseudomonas (15.3%), E-coli (11.5%) and Haemophilus influenza (3.8%). The most frequent causes of drug resistance were Ampicillin, Penici-llin, Cefixime, and Ceftazidime (100% resistance). The most sensiti-ve antibiotics were vancomycin and imipenem (100% sensitivity). Based on the conventional treatment, clinical response to local gentamicin was approximately 60%. Sulfacetamide was associated with no clinical response in 40% of cases.
Conclusion: The antibiogram and clinical response to empiric treatment showed that resistance to ampicillin and some third generation of cephalosporine was 100%. Aminoglycosides’ sensitivity was more than 50% locally and systemically. Our recommendation is performing eye discharge culture before antibiotic treatment. More studies with numerous cases should be done for better definition of bacterial resistance.
Jila Yavarian , Nazanin Zahra Shafiei Jandaghi, Farhad Rezeai , Talat Mokhtari Azad,
Volume 72, Issue 1 (4-2014)
Abstract
Background: Influenza viruses are one of the most important etiological agents of res-piratory disease in humans and cause epidemics and pandemics with substantial mor-bidity and mortality worldwide. Vaccination and antiviral treatments are the sole and essential way for the prevention and control of influenza infection. During an influenza epidemic before the production of effective vaccine, antiviral treatments are the first step for the prevention and treatment of influenza infection. Adamantanes and neuraminidase inhibitors are influenza antiviral drugs. Because of the increase of drug resistant viruses, the aim of this study was the evaluation of the antiviral drug resistance in influenza A/H3N2 viruses from 2005-2013 in Iran.
Methods: In this study 50 influenza A/H3N2 viruses isolated in cell culture were tested. All samples were subjected to M and NA gene sequencing at the National Influenza Center, School of Public Health, Tehran University of Medical Sciences. RNA was ex-tracted from 200 µl of cell culture supernatants using the Roche high pure viral nucleic acid kit. RT-PCR with the Qiagen one step RT-PCR kit was done. The expected size of the PCR products were analyzed by electrophoresis using 1% agarose gels. The PCR products were sequenced for finding the drug resistant mutants.
Results: All influenza A/H3N2 viruses except four viruses circulating during 2005-2006 had Ser31Asn mutation at M2 channel protein. In the analysis of neuraminidase gene none of the A/H3N2 viruses had K292R, E119V and N294S mutations responsible for drug resistant strains.
Conclusion: This study showed circulating A/H3N2 viruses was resistant to adaman-tanes but susceptible to neuraminidase inhibitors. The national data analyzed in this re-search may help increase knowledge about influenza virus antiviral drug resistance, which is a global public health concern. The authors suggested continuing this study and also the investigation of antiviral drug resistance of influenza A/H1N1 and B viruses.
Mohammad Mehdi Soltan Dallal , Samaneh Motalebi Motalebi , Hossein Masoumi Asl , Abbas Rahimi Forushani , Mohammad Kazem Sharifi Yazdi, Zahra Rajabi , Nooshin Aghili ,
Volume 72, Issue 11 (2-2015)
Abstract
Background: Diarrhea is the most common bacterial infections, and the main cause of death in the children. Worldwide, food and waterborne diseases are estimated to cause more than two million deaths per year. Foodborne diseases and resistance to antimicrobial agents are two problems worldwide and are increasing. However, standard surveillance systems do not routinely collect information on controls. The aim of this study was to analysis epidemiological data of foodborne outbreaks at the country level.
Methods: This is a descriptive study, in total 305 fecal swab samples from 73 outbreaks during one year from April 2012 to March 2013 in different provinces of Iran, were collected and transferred to the microbiology laboratory of Public Health School of Tehran University of Medical Sciences to identify the cause’s diarrhea. The patterns of antibiotic-resistance were determined by using Kirby Bauer method.
Results: In total 73 food borne outbreaks that were studied, the largest number 26 (35.6%) were found in Hamadan province with 103 samples (34.2%). Out of 73 outbreaks 40 (54.79%) of were related to foods, 6 (8.22%) to water, and 27 (36.98%) were unspecified (P< 0.0001). Fifty seven outbreaks (78.08%) in the city and 16 outbreaks (21.92%) occurred in rural areas (P< 0.0001). The most dominated Gram-negative isolated organisms were Shigella (6.9%) and Gram-positive bacteria Staphylococcus aureus (12.8%). The dominated age group was under five years (16.4%), and dominant gender group was men 186 (61.8%) (P< 0.0001). In total 69 (22.9%) were hospitalized and 11 deaths were reported. Most clinical symptoms of abdominal cramping (82%), nausea and vomiting (68.4%), bloody diarrhea (23.3%), and non-bloody diarrhea (76.7%). All the isolated gram-negative were sensitive to ciprofloxacin and resistant to clindamycin. The gram-positive were sensitive to cephalexin and resistant to penicillin.
Conclusion: The knowledge of bacterial agent of foodborne diseases and determination of antimicrobial resistance pattern are helpful to reduce the rate of foodborne outbreaks, the cost of treatment. The prevention control of outbreaks is also very important.
Hassan Mahmoudi , Mohammad Reza Arabestani , Seyed Fazlullah Mousavi , Safiyeh Ghafel , Mohammad Yousef Alikhani ,
Volume 73, Issue 1 (4-2015)
Abstract
Background: Staphylococcus aureus is the most important cause of nosocomial infections acquired in the community. Protein A is a major component of Staphylococcus aureus cell wall. In analysis of the nucleotide sequence Protein A encoding spa, locus x consists of 24 base pairs which repeat with high polymorphism. In this study, the spa gene of Staphylococcus aureus isolated from clinical specimens were obtained from patients admitted to the hospital and healthy carriers. Methods: In a cross-sectional study, a total of 200 samples were collected. One hundred fifty samples were obtained from hospitalized patients and 50 samples obtained from staff nasal swabs in Hamadan University Hospitals from October 2013 to August 2014. Disk diffusion antibiotic susceptibility tests performed. The antibiotics studied were Vancomycin (30 µg), Cefoxitin (15 µg) Gentamicin (10 µg), Tetracycline (30 µg), Trimethoprim/sulfamethoxazole (25 µg), Ciprofloxacin (5 µg), Erythromycin (15 µg), Clindamycin (2 µg), Rifampin (5 µg). The tests performed according to the guidelines of clinical and laboratory standards institute (CLSI). It also detect the mecA gene of Methicillin-resistant Staphylococcus aureus strains (MRSA) and genes spa which encodes the protein A by polymerase chain reaction (PCR). The PCR products using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method with enzyme Rsa I (Afa I) were prepared. Results: This methicillin-resistant Staphylococcus aureus strain (MRSA) had the highest sensitivity and resistance to ciprofloxacin and clindamycin. Totally, 8 amplicon with different sizes for the spa gene were identified. A total of 9 patterns polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) were found. Some of these patterns between Staphylococcus aureus isolated from clinical specimens and nasal carriers were common. Conclusion: There is a similar pattern of spa gene among patients admitted to the hospital and staff, according to our findings. Analysis of the patterns can reduced transmission of infection in both hospital staff and patients. Also it can help the physicians for correct management of infections.
Fariba Jaffary , Latifeh Abdellahi , Mohammad Ali Nilforoushzaheh ,
Volume 75, Issue 6 (9-2017)
Abstract
Cutaneous leishmaniasis (CL) is an endemic parasitic disease of major health impact in many parts of the world and is caused by several species of the protozoan parasite Leishmania. Antimonial compounds (i.e glucantime and pentostam) are the first-line treatment for cutaneous leishmaniasis with emerging drug resistance as a problem. The control of Leishmania is further complicated by the emergence of drug-resistant parasites. In the clinical settings, resistance to SbV containing drugs is now well established and it was found to occur in South America, Europe, the Middle East and most notably in India. Clinical resistance to organic pentavalent antimonials, in the form of sodium stibogluconate (pentostam) or N-methylglucamine antimoniate (glucantime), has long been recognized. However, it is unknown whether the clinical failure of chemotherapy is attributable to the development of drug resistance mechanisms in the parasite or to a variety of host factors that might also contribute to low drug response. Reported rate of drug-resistance to antimonial compounds in Iran varies from 9.4% to 94.2% and there is not any comprehensive study on this issue. Indeed, in the endemic region treatment with SbV fails in more cases; thus, in general patients infected with resistant parasites are unresponsive although exceptions have been reported. This article aims to review the mechanisms of drug resistance to these compounds. The main resistance factors include genetical, enzymatic, intracellular (such as apoptosis and cytoskeleton changes) and resistance proteins. Also, mechanisms related to drug transport and intracellular activation are discussed. Various methods of drug resistance detection such as culture and molecular methods (i.e polymerase chain reaction) are reviewed. Although the exact mechanism of action glucantime is not clear, it seems that protein and gene factors involved in cellular drug entry are the main causes of drug resistance. Cross-sectional studies on meglumine antimoniate resistance in endemic areas of cutaneous leishmaniasis in Iran are highly recommended. Also, studies for evaluation of alternatives therapies for antimonial resistant cases are required.
Niloufar Majdabadi, Mehraban Falahati , Fariba Heidarie-Kohan , Shirin Farahyar , Parvaneh Rahimi-Moghaddam, Mahtab Ashrafi-Khozani ,
Volume 75, Issue 11 (2-2018)
Abstract
Background: 2-phenylethanol is a colorless and aromatic compound with antimicrobial effects which is used extensively in perfumes and cosmetics, as well as in the food industry. Chronic vulvovaginal candidiasis is a vulvovaginal inflammation which is caused by Candida spp. Resistance to clotrimazole which is one of the most common drugs in the treatment of this disease was reported in many patients. In order to improve the treatment, the effect of 2-phenyl ethanol was investigated in combination with clotrimazole on Candida species isolated from chronic vulvovaginal candidiasis.
Methods: This interventional study was performed in Iran University of Medical Sciences from February, 2016 until December, 2016 on Candida species isolated from women with chronic candidial vulvovaginitis who had been referred to Lolagar Hospital of Tehran. All specimens were examined by direct microscopy, culturing on Candida CHROMagar medium (to primary identification), sabouraud dextrose agar medium) to preservation the isolates) and determining the internal transcribed spacer (ITS) sequence (in order to final determination of Candida species). Then clotrimazole and 2-phenyl ethanol alone and in combination, was examined on isolated species, according to Clinical and Laboratory Standards Institute (CLSI) M27-A3 protocol (micro-broth dilution method). Finally, findings were analyzed.
Results: From 40 detected strains of Candida species in this study, 95% were Candida albicans and 5% were Candida africana. The mean minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of clotrimazole were 24.73±28.87 µg/ml and 30.18±33.004 µg/ml, respectively and the mean MIC and MFC of 2-phenylethanol were 2580±932.38 µg/ml and 3200±1403.29 µg/ml, respectively. The MIC50 and MIC90 of clotrimazole were 16 and 64 µg/ml, respectively. The MIC50 and MIC90 of 2-phenylethanol were both 3200 µg/ml. Most of the isolates were resistant to clotrimazole (82.5%). In combination test, the mean MIC of 2-phenylethanol and clotrimazole alone were 3200±0 µg/ml and 56±40.16 µg/ml, respectively. The fractional inhibitory concentration index (FICI) range was 0.14-0.37. Also, there was a significant difference between clotrimazole MIC values alone and in combination (P= 0.021).
Conclusion: The synergistic effect was observed in combination of clotrimazole and 2-phenylethanol.
Amir Hasanzadeh , Mohammad Reza Pourmand , Shahram Gooran , Hasan Hosainzadegan , Asghar Tanomand , Gholamreza Pourmand ,
Volume 76, Issue 9 (12-2018)
Abstract
Background: Escherichia coli (E. coli) is one of the most important infectious agents in patients undergoing prostate biopsy. It belongs to a large family of gram-negative rods, Enterobacteriaceae. This family includes members of the normal flora of the intestine that are only occasionally pathogenic. Recent considerations of rectal colonization with fluoroquinolone-resistant E. coli shows the need to change strategy of treatment of infection in patients undergoing prostate biopsy. Therefore, the purpose of this study was to determine molecular typing of fluoroquinolone resistant (FQR) E. coli rectal isolates and associated infections in patients undergoing prostate biopsy.
Methods: In this prospective cohort study, rectal swabs were collected from 158 male patients before prostate biopsy at the Urology Research Center of Sina Hospital, Tehran, Iran, from March 2015 to February 2016. The FQR organisms were isolated using selective media, and antibiotic susceptibility pattern was determined for following antibiotics, ampicillin, levofloxacin, cotrimoxazole, amoxicillin-clavulanate, cefazolin, ceftazidime, cefepime, gentamicin, piperacillin-tazobactam, nitrofurantoin, amikacin, fosfomycin, imipenem. In general, phylogenetic background, prevalence of E. coli sequence type 131 (ST131) and its subclones (H30 and H30-Rx ST131) were compared in two groups of FQR E. coli rectal colonization and clinical isolates.
Results: In total, 73 patients had a positive rectal culture for FQR gram-negative bacteria, the most prevalent isolate of which was E. coli. Phylogenetic group B2 was most predominant, followed by A, E, C and D, B1 and F. The antibiotic susceptibility patterns for the FQR organisms showed high levels of resistance to ampicillin and trimethoprim-sulfamethoxazole, while the resistance to amikacin, fosfomycin and imipenem remained very low. In general, antibiotic resistance to several antibiotic was mainly detected in group B2 and with ST131 genotype. Despite the increase in infections among patients colonized with strains of E. coli ST131, its frequency was almost statistically significant between colonized and infected groups.
Conclusion: The ST131 pathogen has a high prevalence in rectal colonization and post prostate biopsy infections, which showed widespread resistance to common antibiotics.
Ghobad Moradi, Seyyede Maryam Bechashk, Nader Esmailnasab , Behzad Mohsenpour, Rashid Ramazanzadeh , Daem Roshani , Ebrahim Ghaderi,
Volume 77, Issue 2 (5-2019)
Abstract
Background: Metronidazole resistant clostridium difficile is one of significant pathogens in Iran. It is one of the WHO-declared microbial resistance emergencies. Prevalence of metronidazole resistant clostridium difficile is rising. The aim of this study was to detect prevalence of metronidazole-resistant clostridium difficile using meta-analysis in Iran.
Methods: This study was conducted as a meta-analysis. Articles and derivatives were reviewed by two researchers. Initially, each of the researchers searched the databases separately and used all available Persian and English articles in Kurdistan University of Medical Sciences, Iran, from October 2017 to February 2018. Persian databases (including Magiran, Irandoc, Barakat and SID) and international databases (including PubMed, Sciencedirect, and Scopus) were searched during this period (2007-2016) with a combination of phrases and keywords. The list of references to these studies has also been evaluated and relevant articles have been included in the study. First, all the articles were extracted and then duplicated articles were deleted using the EndNote software, version X6 (Thomson Reuters™, New York, NY, USA) through the search for electronic banks. Such that the high heterogeneity (50% Results: From the search of medical databases at first, 68 articles were selected. In total, 19 remaining studies entered the meta-analysis phase. In this study, the overall prevalence of clostridium difficile is 32.57% (CI95%: 21.86-44.30); in 2016 it was 55.25% (CI95%: 50.22-60.19) and in 2009 was14.26% (CI95%: 12.32-16.37). The heterogeneity was estimated to be 98.7% (CI95%: 98.5-98.8).
Conclusion: Based on the results of this study, the prevalence of metronidazole resistant clostridium difficile in Iran is high and increasing.
Monireh Rahimkhani,, Zahra Rajabi,
Volume 80, Issue 7 (10-2022)
Abstract
Background: Considering the frequency of MRSA strains in hospitals and medical centers as well as in different communities, it seems necessary and important to observe the use of appropriate drugs in order to reduce antibiotic resistance and reduce the economic costs of treatment. This study aimed to investigate the antibiotic resistance pattern of MRSA isolated from blood and wound samples of patients. The study patients were hospitalized in different departments in a number of Tehran University of Medical Sciences hospitals.
Methods: In this descriptive cross-sectional study from September 2021 to February 2022, the blood and wound samples of the patients were collected and referred to laboratory. Staphylococcus aureus had identified by phenotypic and biotypic tests. MRSA isolates were screened by showing resistance to Cefoxitin by disc diffusion method and finally confirmed by examining the mecA gene by PCR. The microbial resistance pattern of MRSA was also measured by disk diffusion method and resistance to Vancomycin was confirmed by E.test.
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Results: 41 isolates from 87 Staphylococcus aureus samples were confirmed as MRSA by present the mecA gene. The mecA gene was detected in all MRSA by PCR method. The antibiotic resistance pattern showed the highest sensitivity to Vancomycin and Linezolid with 100% sensitivity and the highest resistance to three antibiotics Erythromycin, Ceftriaxone and Cloxacillin with 97.57%by disk diffusion method. The most MRSA strains were isolated from the ICU department with 13 cases and the least MRSA strains were isolated from the two NICU and pediatric departments with one case.The majority of the population infected with MRSA belonged to the age group of 40-65 years.
Conclusion: The prevalence of microbial resistance with high dispersion was obtained among MRSA strains isolated from clinical samples; which indicates a significant increase in resistant strains and requires a quick and timely diagnosis to prescribe the appropriate antibiotic.
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