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Showing 6 results for Antibiotic Resistance
Evaluating the antibacterial, hemolytic and cytotoxic activities of the Iranian Rana ridibunda skin extract as a new source of antimicrobial compound
Asgharian Am, Mohammadi M,
Volume 69, Issue 10 (1-2012)
Abstract

Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background: Amphibian skins possess various antibacterial compounds that are effective against some microbial pathogens and are mostly released in response to environmental stress. In fact, the skin of Rana ridibunda, a large green frog, is a rich source of antimicrobial compounds that can be developed for therapeutic use. In the present study, the skin extract of Iranian Rana ridibunda was evaluated for its antimicrobial, hemolytic and cytototoxic activities.
Methods : The frog specimens were collected from Minoodasht located in Golesten province in Iran, during 2009. Subsequently, their skins were removed and the intended compounds were extracted. The crude extract was partially purified by gel filtration chromatography. The antimicrobial effects of skin extract were assessed against various microorganisms such as Escherchia coli, methicillin-resistant and -sensitive Staphyloccus aureus, vancomycin-resistant and -susceptible Enteroccus fecalis, Pseudomonas aeroginosa and Candida albicans. In addition, its minimum inhibition concentration, cytotoxic and hemolytic activities were determined.
Results : The crude extract of Rana ridibunda skin had valuable antimicrobial effects against methicillin-resistant and -susceptible S. aureus in comparison with E.coli and vancomycin-resistant and -susceptible E. fecalis. Besides, no antimicrobial activities were seen against P. aeroginosa or C. albicans. Moreover, the hemolytic and cytotoxic activities of the skin extract were minimal.
Conclusion: The antimicrobial activity of Iranian Rana ridibunda was comparable to those isolated from other Rana species. In conclusion, the skin extract of Rana ridibunda had the potential for a new therapeutic agent against the emerging drug-resistant bacteria, particularly methicillin-resistant and -sensitive S. aureus.


The prevalence of nosocomial infections caused by Enterobacter cloacae and antibiotic resistant patterns in samples isolated from patients in two hospitals in Tehran
Rahbar Mohammad, Azimi Leila, Mohammad-Zadeh Monaaranak, Alinejad Faranak, Soleymanzadeh Somayeh, Sattarzadeh Mahboobeh, Rastegar Lari Abdolaziz,
Volume 70, Issue 3 (6-2012)
Abstract

Background: The increasing use of β-lactam antibiotics in clinics for the treatment of different bacterial infections since early 1980s has led to increased rates of resistant bacteria isolated from patients. One of the problems in the treatment of nosocomial infections is related to resistant bacteria such as Enterobacter cloacae due to cross resistance through extended-spectrum beta-lactamase production. The aim of this study was to determine the prevalence of extended-spectrum beta-lactamase producing E. cloacae from different clinical specimens collected from hospitalized patients.

Methods: In the present study, 101 E. cloacae confirmed by standard specific microbiologic tests were collected from different specimens in Milad and Motahri hospitals in Tehran, Iran during February 2010 and September 2011. Antibiotic susceptibility tests were conducted according to the process recommended by the Clinical and Laboratory Standards Institute for 13 antibiotics of choice. Extended-spectrum beta-lactamase producing strains were screened for by combined disk method as a phenotypic diagnostic test.

Results: From a total of 101 E. cloacae, 33 (33%) were shown to produce extended-spectrum beta-lactamase by phenotypic tests 5% of the bacteria were resistant to imipenem too.

Conclusion: This study clearly showed the high prevalence of resistance to broad-spectrum beta-lactam antibiotics in the isolated E. cloacae among which 5% were multi drug resistant. All the isolated E. cloacae were susceptible to Colistin. These results can be alarming for physicians treating resistant E. cloacae infections, especially extended-spectrum beta-lactamase producing species.


Determining a pattern for antibiotic resistance in clinical isolations of pseudomonas aeruginosa
Shahram Shahraki Zahedani , Mojdeh Jahantigh , Yousef Amini ,
Volume 76, Issue 8 (11-2018)
Abstract
Background: Pseudomonas aeruginosa is an opportunistic pathogen and one of the important factors of hospital infection. It causes many issues such as urinary tract infections, respiratory infection in cystic fibrosis patients, and wound infection in burn patients, septicemia and meningitis. Antibiotic resistance through various mechanisms is one of the challenges for the treatment of pseudomonad-caused infections. According to the inherent and acquired capacity of this bacterium in creating resistance against the antimicrobial factors, it is very important to identify a pattern for its antibiotic resistance. The aim of this study was to deliberate the frequency of pattern antibiotic resistance of pseudomonas aeruginosa strains.
Methods: In this cross-sectional study, 200 pseudomonas aeruginosa isolations (from 86 males and 114 females) were collected from different samples such as urine, blood, wound, catheter and other samples from teaching hospitals in Zahedan City during nine-month period in 2017. After conducting biochemical tests and confirming bacterium type, based on Clinical Laboratory Standards Institute (CLSI), the antibiotic resistance of strains for 10 antibiotics was determined using disk diffusion method. In addition, the minimum inhibitory concentration of three antibiotics such as imipenem, piperacillin/tazobactam and ceftazidime were determined through E-test. The Chi-square test was used for statistical analysis through the SPSS software, version 16 (IBM SPSS, Armonk, NY, USA).
Results: Out of 200 pseudomonas aeruginosa isolations (from 86 males and 114 females), the maximum resistance was related to ciprofloxacin (37%) and gentamicin (28.5%). The minimum resistance was related to piperacillin/tazobactam (6.5%) and ceftazidime (6%). The highest separated strain was from urine sample (54%), blood sample (23.5%) and wound sample (10.5%). Additionally all strains were sensitive to colistin. In this study, the percentage of multidrug-resistance (MDR) and extensively drug-resistant (XDR) strains were investigated, which were 13% and 5.5%, respectively.
Conclusion: In this study, pseudomonas aeruginosa isolates had the lowest resistance to ceftazidime which this antibiotic could be the main treatment option. The high prevalence of MDR strains is a serious warning.

Dysentery caused by macrolide and fluoroquinolone resistant Campylobacter coli in central area of Iran
Elnaz Abbasi , Behzad Khansarinejad , Ehsanollah Ghaznavi-Rad,
Volume 76, Issue 11 (2-2019)
Abstract
Background: Campylobacter genus is considered some of the most important agents of bacterial gastroenteritis worldwide. Campylobacter coli (C. coli) is accounted to at least 25% of all Campylobacter related diarrheal diseases moreover, C. coli infections can result in severe complications, such as bacteremia, sepsis, meningitis and spontaneous abortion. Finally, there is evidence that the frequency of antimicrobial resistance is higher in C. coli, when compared to C. jejuni. There is no data regarding the frequency and antibiotic resistance profile of C. jejuni isolated from human gastroenteritis samples. The present study aimed to determine the frequency and antibiotic resistance patterns of Campylobacter coli isolated from infectious diarrhea samples.
Methods: In a descriptive cross-sectional study, 200 infectious diarrhea samples collected in Arak University of Medical Sciences Hospitals, Markazi Province, Iran, from May to November 2015 were subjected to the study. In order to identify C. coli modified Gram stain, modified charcoal-cefoperazone-deoxycholate agar (mCCDA) and Brucella agar media with filter and CeuE gene polymerase chain reaction (PCR) were accomplished. Antibiotic resistance against tetracycline, erythromycin, ciprofloxacin, ampicillin and gentamicin was evaluated phenotypically and genotypically.
Results: In total, out of 200 modified gram stained samples, 2 cases (1%) of C. coli were identified. Cultivating methods using mCCDA medium found 2 isolates (1%), 3 isolates (1.5%) were grown on Brucella agar with filter and 5 cases (2.5%) were determined as C. coli using PCR assay. Antibiotic resistance was observed in 5 cases against tetracycline, erythromycin and ciprofloxacin (100%), in 4 cases against ampicillin (80%), in 2 cases against gentamicin (40%), in 5 cases with CmeB, 23srRNA mutation in, qnrS, tet (o) (100%), in 4 cases with gyrA4 (80%), in 3 cases with gyrA5 (60%), in 5 cases with gyrA6 (100%), in 4 cases with Oxa61 (60%) and in 1 case with aphA-3-1 (20%).
Conclusion: In this present study C. coli with low prevalence and entire resistance to ciprofloxacin and erythromycin which are the first line antibiotic for the treatment of campylobacter gastroenteritis is introduced as a causative agent of gastroenteritis in patients at central part of Iran.

Comparison of antibiogram test results of patients suspected of urinary tract infection with two methods, fast and classic
Hamid Reza Ghasemi Basir , Fariba Keramat, Abbas Moradi, Yeganeh Ghasemi, Ali Saadatmand,
Volume 79, Issue 12 (3-2022)
Abstract
Background: Urinary tract infections are among the most common diseases in different communities and occur in all age groups. Failure to diagnose the disease correctly and promptly can cause complications such as damage to the urinary tract and kidney parenchyma, increased blood pressure, uremia. Also, in pregnant female patients It may lead to premature birth and even abortion. Therefore, correct and timely administration of antibiotics is very important in the treatment of patients. This study aimed to compare the results of antibiogram testing of patients with suspected urinary tract infections by both rapid and classical methods.
Methods: This cross-sectional study was performed from the beginning of March to the beginning of September 2019, on patients with urinary tract infection Who had been referred to Sina Hospital of Hamedan, Iran. Urine samples were collected 20 cc from patients. The test was performed directly at the same time with urine culture to determine antibiotic susceptibility. The agreement between the two methods was considered as a huge error, major error and minor error. Finally, the data were statistically analyzed with SPSS software version 16.
Results: 92 patients, 23 men (25%) and 69 women (75%) with a mean age of 53.18±18.49 years were included in the study. Direct testing had a significant agreement with the standard test in 90.8% of the results (P<0.001). 9.2% of the antibiogram tests did not match, of which 0.3% were huge errors, 4.7% were major errors and 4.2% were minor errors. The highest number of microorganisms found were Escherichia coli (n=66), Klebsiella pneumoniae (n=13), Pseudomonas aeruginosa (n=6), Acinetobacter (n=1), Enterococcus (n=2), Alcaligenes (n=1), Streptococcus (n=1), Staphylococcus haemolyticus (n=1) and Moraxella (n=1) respectively. The highest rates of urinary tract infections were with Escherichia coli, third-generation cephalosporin antibiotics, and broad-spectrum antibiotics.
Conclusion: The agreement between the direct and standard antibiogram method was acceptable, and the direct antibiogram method can be cited by doctors in many cases.
 

Investigation of the frequency of resistance to fluoroquinolones in Salmonella enterica subspecies enterica serovar Enteritidis isolates isolated from hospital gastroenteritis samples
Kasra Mardani, Farhad Nikkhahi, Fatemeh Fardsanei,
Volume 81, Issue 9 (12-2023)
Abstract
Background: Salmonella enterica subspecies enterica serotype Enteritidis (S. Enteritidis) is one of the leading causes of food-borne infections associated with the consumption of contaminated food products of animal origin in humans. gastroenteritis due to Salmonella is usually a self-limiting disease and does not require antibiotic therapy. However, antibiotic treatment for salmonellosis may be lifesaving for patients with severe infections.The objective of the present study was to examine antimicrobial resistance and determine its genetic basis in recently isolated S.Enteritidis strains.
Methods: During this study, in a cross-sectional descriptive study, 44 isolates of Salmonella enteritidis from human sources were investigated between September 2021 and September 2022.. After identification of the isolates using phenotypic and molecular methods by Multoplex-PCR, antibiotic resistance testing was performed according CLSI 2023. The strains were examined for the presence of qnrA,qnrB,qnrS and gyrA resistance genes by PCR.
Results:  In a cross-sectional descriptive study, 44 isolates of Salmonella Enteritidis from human sources were investigated between September 2022 and September 2023. 100% of the strains were sensitive to imipenem and meropenem, and the sensitivity to the antibiotics ceftriaxone, ceftazidime, and cefotaxime were 93.2%, 90.9%, and 94.1%, respectively. 81.8% of isolates were sensitive to cotrimoxazole, sensitivity to ampicillin was 84.1%. Only 9.1% of isolates were sensitive to ciprofloxacin. Based on MIC results, 16 isolates had MIC between 0.002 and 0.064 and were placed in the sensitive area. 28 isolates had MIC between 0.125 and 0.5 and were placed in the area of reduced sensitivity. None of the strains resistant to disk diffusion method were resistant to MIC method. qnrA, qnrB and qnrS genes were not observed among ciprofloxacin resistant strains. All nalidixic acid resistant strains had gyrA gene.
Conclusion: In general, it was shown in this study that the resistance to the fluoroquinolone family is increasing among Salmonella Enteritidis isolates. On the other hand, we see a decrease in the sensitivity and prevalence of strains resistant to broad-spectrum cephalosporins among serovar Enteritidis, which is the drug of choice for extraintestinal infections.

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