Showing 120 results for Ct
Maryam Varposhti, Ahya Abdi Ali, Parisa Mohammadi, Azra Saboora,
Volume 1, Issue 1 (11-2013)
Abstract
Biofilm of Pseudomonas aeruginosa, an opportunistic pathogen, can cause serious health problems, such as chronic infections, especially in immunocompromised patients. Many studies have suggested administration of new generation of antibiotics, as P. aeruginosa biofilms have developed high resistance to antimicrobial drugs. This study reports the inhibitory effect of three medicinal plant extracts and an essential oil on biofilm formation by a clinical isolate of P. aeruginosa. In this study biofilm formation of P. aeruginosa strain 214 was determined in presence of three plant extracts, Cyclamen coum, Dianthus orieltalis and Origanum majorana, and Zataria multiflora Bio essential oil. Minimum Biofilm Inhibitory Concentrations (MBICs) were determined by microdilution techniques and XTT assay. The C. coam extract and Z. multiflora Bio essential oil inhibited biofilm formation completely at concentrations<0.062 mg/ml and 4 µl/ml, respectively. The D. orientalis and O. majorana extracts did not inhibit biofilm formation at the used concentrations (0.003 – 8 mg/ml). The results of this study indicate that some plant extracts at low concentrations may provide a complementary medication for biofilm-associated infections. Further evaluations are required to validate the antibiofilm effect of these medicinal plants.
Somayeh Azami, Ahya Abdi Ali, Ezzat Asgarani,
Volume 1, Issue 1 (11-2013)
Abstract
Pseudomonas aeruginosa is among the most important pathogens in the nosocomial infections. A genetic mobile element, the integron, is one of the major agents involved in dissemination of multi-drug resistance among gram negative bacteria. During a descriptive study from October 2009 to August 2010, some 130 P. aeruginosa clinical isolates were collected from different wards of three hospitals in Tehran. The Minimal inhibitory concentration (MIC) of 4 antibiotics conventionally used in clinical settings against the isolates was determined by E-test method. Also, the existence of integron classes and metallo-β-lactamases (blaVIM-1, blaIMP-1, and blaVIM-2) were investigated by PCR assay. Out of 130 isolates, 74 (56.9%) carried class 1 integron. None of the isolates harbored integrons class 2 and 3. Also, the blaVIM-1 gene was detected in 10 (13.3%) high level ceftazidime and imipenem- resistant isolates that carried class 1 integrons. The blaIMP-1 and blaVIM-2 genes were not detected in any isolates. In the present study, the antibiotic resistance rates in class 1 integron-positive isolates of P. aeruginosa were significantly higher than those lacking this integron , e.g., 82.6% resistance versus 17.3% sensitivity to ceftazidime. Also, 13.3% of ceftazidime and imipenem resistant isolates was metallo-β-lactamase producer. This indicates that all metallo-β-lactamase genes are correlated with class 1 integrons. These results imply that the blaVIM-1 gene has been presumably dispersed into P. aeruginosa isolates with the help of class 1 integron element.
Sonali Jain, Amit Kumar Singh, Ravinder Pal Singh, Jyoti K Bajaj, Ajit S Damle,
Volume 2, Issue 1 (1-2014)
Abstract
Introduction : The decreased level of immunity in Human Immunodeficiency Virus (HIV) infected patients increases their vulnerability to various opportunistic fungal infections. Oral candidiasis has been found to be the most common fungal infection among HIV infected patients. The present study was conducted to evaluate the spectrum of various opportunistic fungal infections and their correlation with CD4+ counts. Methods: A total of 163 clinically suspected cases of fungal infections with HIV seropositive status were studied. Results: The most common infections observed were oropharyngeal candidiasis (39.26%) followed by cryptococcal meningitis (6.74%). The study showed opportunistic fungal infections in 46.6% of HIV infected patients with CD4+ counts ≤200 cell/ µl. Conclusion: Early diagnosis and prompt antifungal treatment is necessary to decrease the morbidity and mortality associated with the infections to increase the survival of HIV infected patients. J Med Microbiol Infec Dis, 2014, 1 (2): 4 pages.
Pantea Jalali, Seyed Fazlollah Mousavi, Nima Rezaei,
Volume 2, Issue 1 (1-2014)
Abstract
Introduction : Haemophilus influenzae is a gram-negative bacterium causing a variety of respiratory infections in developing countries, especially in children. Nasopharynx carriers of H. influenzae are the prominent source and transitional vectors of invasive diseases. As very limited information on H. influenzae carriage rate in Iran was available, an evaluation on prevalence of this bacterium in children ≤ 6 years old seems crucial. Methods: Totally 533 mucus samples were collected using nasopharyngeal swabs from children ≤ 6 years old who lived in 4 nursery centers in Tehran or refereed to the Children's Medical Center of Tehran, Iran, from August 2011 to October 2012. The samples were transported in Stuart transport medium to the Microbiology Laboratory of Pasteur Institute Tehran, Iran, and were cultured on chocolate agar containing bacitracin antibiotic. The initial diagnosis for detection of H. influenzae was performed by standard biochemical tests, and confirmation was achieved by PCR assay targeting outer membrane protein (omp) P6 gene. Results: Based on primary cultures and biochemical tests, out of 533 samples, 182 (33%) showed to be H. influenzae positive, but PCR assay confirmed presence of H. influenzae in 153 (28%) isolates 56(37%) belonged to girls and 97 (63%) to boys. The prevalence of H. influenzae in three different age groups: ≤ 24, 25-48, and 49-72 month-old children were 31 (20%), 69 (45%), and 53 (35%), respectively. Conclusion : Our results showed a high rate of H. influenzae carriers among children ≤ 6 years old, which is similar to those of other unvaccinated countries. H. influenzae carriage rate was associated to age and respiratory infection diseases. The children aged 25-48 months showed a higher rate and the rate reduced with increase in age. Further investigation including molecular studies is required to obtain the carriage rate throughout the country. J Med Microbiol Infec Dis, 2014, 1 (2): 5 pages.
Adamu Babayo, Thairu Yunusa, Idris Abdullahi Nasir, Marycelin B. Baba,
Volume 2, Issue 2 (4-2014)
Abstract
Introduction : Human cytomegalovirus (HCMV) is able to go into latency and is the most common cause of congenital infections in humans. Its clinical manifestations range from asymptomatic forms to severe fetal damage, and in rare cases, fetal death due to abortion. This prospective cross-sectional study was designed to determine the seroprevalence of HCMV infection in pregnant women attending antenatal clinics of the University of Maiduguri Teaching Hospital, Nigeria, and to identify its possible risk factors. Methods: Blood samples were collected from 182 pregnant women aged 16 to 40 years. Samples were tested for anti-CMV specific IgG and IgM antibodies using the commercial ELISA Kits. A brief structured questionnaire was used to obtain some of their sociodemographic characteristics. Results: Seroprevalence of CMV-specific IgG and IgM were 79.1% and 2.2%, respectively. Of 182 women, 144 had previous exposure to CMV [IgG (+) IgM (-)], 3 had CMV reactivated infection [IgG (+) IgM (+)], 37 were susceptible to CMV [IgG (-) IgM (-)], and only one woman had recent infection [IgG (-) IgM (+)]. There was no significant association between seroprevalence and any of the studied sociodemographic data (p>0.05). Conclusion: The findings of this study indicated that a large number of the studied pregnant women were non-immune (susceptible) to HCMV infection, while four of them had active HCMV infection, which places their unborn children at risk of acquiring congenital HCMV infections. Therefore, it is necessary to screen pregnant women for CMV infection as part of their antenatal care and follow-up them to assess the effect that CMV might have on their fetuses. J Med Microbiol Infec Dis, 2014, 2 (2): 7 pages.
Atefeh Pilehvar Zavareh, Mohammadreza Mahzounieh, Mohammadreza Shirzadi, Rouzbeh Bashar, Alireza Zavareh, Nader Howaizi, Firuzeh Farahtaj, Alireza Janani, Alireza Gholami,
Volume 2, Issue 2 (4-2014)
Abstract
Introduction: The most common mode of rabies virus transmission is through a bite wound or contact of broken skin with saliva of a rabid animal. Various other routes of virus transmission include exposure of mucous membranes (i.e. eyes, nose, and mouth) to infected saliva of a rabid animal, aerosol transmission, and corneal transplantation. Laboratory workers during work with rabies virus and veterinarians during examination and surgery of rabid animals may be at risk for exposure to saliva or other infectious fluids splashing into their eyes. The aim of this study was to investigate the possibility of ocular rabies pathogenesis in mice as an animal model. Our results will determine if rabies virus strains challenge virus standard (CVS) and street rabies virus (SRV) are able to infect the central nervous system (CNS) of mice through the ocular route. Methods: This study was performed in two experiments. In experiment 1, different lethal doses of fixed rabies virus strain CVS were made and instilled into both eyes of test mice. In experiment 2, concentrated rabies virus strains CVS and SRV were instilled into both eyes of the test mice. Mice in all groups were kept for 3 months and tested by fluorescent antibody test (FAT) for detection of the presence of viral antigen in brain tissue. Results: Mice with ocular instillation of fixed and street rabies viruses developed no clinical symptoms of rabies and all were healthy and alive during the 3-month observation period. The FAT results were negative in both experiments. Conclusion: Our results suggest that CVS and SRV viruses are not able to infect the CNS of mice via intact conjunctiva and cornea.
Dr. Tahereh Valadbeigi, Dr. Ali Mohammad Bahrami, Dr. Minoo Shaddel,
Volume 2, Issue 2 (4-2014)
Abstract
Introduction: Natural products have been the most successful source of potential drug leads. One of them is lichens, which have been used since antiquity as natural sources of drugs. The aim of this study was to investigate the antibacterial and antifungal activity of different extracts of the Iranian lichens in Ilam Province. Methods: The aqueous, acetone, and methanol extracts of 6 lichen species, including Caloplaca variabilis, Fulgensia subbracteata, Lecanora muralis, Physcia adscendens, Psora decipiens, and Megaspora verrucosa, were produced using Soxhlet extractor. Then, antibacterial and antifungal activities of them against 6 standard strains of bacteria, including Enterococcus faecalis ATCC 2321, Escherichia coli ATCC 1652, Proteus mirabilis ATCC 2601, Salmonella typhi ATCC 1679, Staphylococcus aureus ATCC 1885, and Staphylococcus epidermidis ATCC 2405 and two fungi, including Fusarium moniliforme and Verticillium dahliae, were evaluated using the disc-diffusion method and the minimal inhibitory concentration was determined by broth tube dilution. Streptomycin (10 µg/ml) and ketoconazole (10 µg/ml) were used as positive controls for bacteria and fungi, respectively. Sterile distilled dimethyl sulfoxide (DMSO) was used as negative control. Results: Methanol extract from F. subbracteata and L. muralis lichens showed relatively high antibacterial activities (p<0.01), whereas aqueous extracts showed no activity against the microorganisms and only acetone extract of L. muralis showed antibacterial activity against the S. epidermidis (MIC=500). Methanol extracts of F. subbracteata and L. muralis had higher antifungal activities than others. Conclusion: The methanol extracts of L. muralis and F. subbracteata showed the highest activity against the bacteria and fungi and it seems that they have some antibacterial and antifungal properties.
Mr. Farzin Khorvash, Mr. Mohammad Reza Yazdani, Miss Shiva Shabani, Miss Houri Alizadeh, Mr. Ali Asghar Soudi, Mrs. Parisa Shoaei, Mr. Behrooz Ataei, Mr. Majid Yaran,
Volume 2, Issue 2 (4-2014)
Abstract
Introduction: Pseudomonas aeruginosa is a serious challenge for antimicrobial therapy, due to chromosomal mutations or intrinsic resistance to various antimicrobial agents, such as Metallo-β-Lactams (MBL). This study aimed to investigate the prevalence of β-lactamases encoding genes among P. aeruginosa strains isolated from intensive care unit (ICU) patients by phenotypic and multiplex PCR methods. Methods: A total of 48 non-duplicate strains of P. aeruginosa were collected from different clinical specimens of patients hospitalized in ICU wards of a teaching hospital in Isfahan, Iran. Susceptibility test was performed by disk diffusion method. All meropenem resistant strains were subjected to modified Hodge test (MHT) for detection of carbapenemases. Multiplex PCRs were performed to detect β-lactam-resistant P. aeruginosa isolates. Results: In disk diffusion method, P. aeruginosa strains showed the most (97.9%) resistance against imipenem and meropenem and the least (45.8%) against colistin. Thirty-six (75%) out of the 48 isolates were multidrug resistant. PCR amplification of β-lactamase genes showed the presence of blaVIM genes in 7 (14.6%) and blaIMP in 15 (31.3%) strains. Also, blaSME, SPM, GIM, AIM and NDM genes were not observed in any of the strains. We only found a statistically significance difference between the presence of blaIMP gene and multidrug-resistant (MDR) positivity and source of specimen (p=0.009 and 0.002, respectively). Conclusion: Rapid and reliable identification of MBLs appears to be necessary for effective treatment of related infections. Besides, our results may provide useful perception to make a more appropriate choice of antibiotics, which may put a stop to carbapenem-resistant infections.
Farzaneh Khoei, Haedeh Mobaiyen, Mohamamad Reza Nahaei, Sanam Sadeghi Mohammadi,
Volume 2, Issue 3 (7-2014)
Abstract
Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) can cause serious and life-threatening hospital- and community-acquired infections. Colonized and infected patients represent the most important reservoir of MRSA in health care facilities. Therefore, in this study, MRSA isolates collected from Shohada Hospital in Tabriz were evaluated for the frequency of mecA gene and their antimicrobial susceptibility in a period of three years, from 2010 to 2012. Methods: A total of 182 S. aureus isolates were collected from clinical specimens and first genotypically identified by detection of nuc gene. Antimicrobial susceptibility test was performed by disc agar diffusion method using cefazolin, methicillin, tetracycline, and cefoxitin according to clinical and laboratory standards institute (CLSI) recommendation. Phenotypic (cefoxitin 30 µg/disc) and genotypic (mecA gene detection by PCR) methods were used for detecting methicillin sensitivity. Results: All isolates expressed S. aureus specific sequence gene (nuc) in their PCR products. Eighty-one (44.5%) isolates were confirmed as MRSA by cefoxitin disc screening test and 97 (53.3%) isolates by showing the presence of mecA gene. All the methicillin sensitive S. aureus (MSSA) isolates and 64 (66%) MRSA isolates were found to be susceptible to cefazolin, but 25 (25.8%) MRSA were resistant to tetracycline and cefazolin. Conclusion: The results of this study showed high frequency (53.3%) of MRSA with no significant differences in rates within the three years of study, indicating the inefficiency of control programs to care for patients with MRSA.
Mir Mostafa Ghamilouie, Zarrintaj Valadkhani, Fariba Khoshzaban,
Volume 2, Issue 3 (7-2014)
Abstract
Introduction: Acanthamoeba is an opportunistic protist, which is ubiquitously distributed in the environment. Infection with Acanthamoeba spp. poses threat to human health, such as, Acanthamoeba keratitis (AK) that is a vision-threatening infection of the cornea. This study aimed to identify the species of Acanthamoeba strains isolated from cornea of keratitis patients by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Methods: Acanthamoeba isolates investigated in this cross-sectional study, were collected from patients referring to Farabi Eye Reference Center. All 10 isolates were subjected to species identification using DNA based method. BspLI (NlaIV) and HpyCH4IV restriction enzymes were used to categorize the PCR amplified DNA by PCR-RFLP method. Results: Six samples were identified as Acanthamoeba palestinensis and 4 isolates as Acanthamoeba culbertsoni, which implies that all the isolates belong to pathogenic strains of Acanthamoeba. Conclusion: Acanthamoeba can enter the corneal tissue and survive in the eye, which results in AK. To the authors' knowledge, no study is available on species identification of this genus using these enzymes and technique. This is the first time in Iran that Acanthamoeba isolates are subjected to species identification using PCR-RFLP method.
Dr. Nadia Saad, Dr. Tehmina Munir, Dr. Maliha Ansari, Dr. Mehreen Gilani, Dr. Mahwish Latif, Dr. Amira Haroon,
Volume 2, Issue 4 (10-2014)
Abstract
Introduction: This study is aimed to compare phenotypic test methods and determine antibiotic susceptibility pattern of AmpC beta-lactamase producing uropathogenic Escherichia coli and Klebsiella pneumoniae in clinical isolates. Method: E. coli and K. pneumoniae were identified by standard microbiological procedures. Screening of AmpC beta-lactamase production was done by using cefoxitin disc (30 µg) showing inhibition zone diameter of <18 mm. Then, screen-positive isolates were subjected to Disc Approximation Test (DAT) and three dimensional extract test (3-DET) methods. Antibiotic susceptibility testing was performed by Kirby Bauer Disc diffusion technique. Results: A total of 120 Gram Negative Rods (GNRs) were included in the study. Amongst them cefoxitin resistant isolates were 68.33% (n=82/120). In these 82 isolates, E. coli were n=57 (69.51%) and K. pneumoniae were n=25 (30.48%). DAT identified 52.43% of AmpC beta-lactamase producing isolates, sensitivity of DAT was found to be 88% with 92% specificity, Positive Predictive Value of 92.68%, Negative Predictive Value of 87.80%, and Diagnostic Accuracy of 90.24%. Antibiotic susceptibility testing by Kirby Bauer Disc diffusion technique showed that carbapenems (meropenem) and tigecycline were of higher therapeutic effects against these resistant pathogens. Conclusion: Introducing simple tests like DAT in the laboratories can control the spread of AmpC beta-lactamase harboring organisms. Carbapenems (meropenem) and tigecycline are of suitable therapeutic effect against these resistant pathogens.
Vahideh Kadaei, Ahmad Rashki,
Volume 2, Issue 4 (10-2014)
Abstract
Introduction: Extended spectrum beta-lactamase (ESBL) producing Escherichia coli generate a major problem for clinical therapeutics and epidemiological study. The incidence of ESBL producing strains among clinical isolates has been steadily increasing during the past few years, and remains an important cause of failure of therapy with cephalosporins. The aim of this study was to determine the antimicrobial susceptibility pattern and prevalence of ESBLs in E. coli isolates taken from different clinical specimens by phenotypic and genotypic techniques. Methods: In this descriptive study, a total of 100 E. coli isolates collected from different clinical specimens were used. The antibiotic resistance pattern to twelve antimicrobial agents was determined by disk diffusion method. The ESBLs producing strains were confirmed by double-disk-diffusion test, and the CTX-M, TEM, SHV, and OXA were detected by PCR. Results: The prevalence of ESBL producing E. coli was 56%. The results show that 95% of ESBL producing E. coli isolates tested were resistant to ceftriaxone and cefotaxime, 93% for ceftazidime, 86% for azithromycin, 79% for cefazolin and 43% to imipenem. Among the ESBL producing E. coli, 48%, 30% and 11% were positive for CTX-M, TEM and SHV genes, respectively. OXA was not found in all isolates. Conclusion: ESBL producing isolates of E. coli have been increasingly recognized and there is a need to carefully formulate therapeutic strategies to control infections in teaching Hospitals. The high percentage of drug resistance in ESBL producing E. coli suggests that routine detection of ESBL is required by reliable laboratory methods.
Mojtaba Moosavian, Nasim Shams, Mehrandokht Sirous,
Volume 2, Issue 4 (10-2014)
Abstract
Introduction: Acinetobacter baumannii, a known causative agent of nosocomial infections, is one of the highly antibiotic-resistant gram-negative bacilli. Carbapenem-resistant Acinetobacter isolates are increasingly reported worldwide. Carbapenems such as imipenem and meropenem are efficient antimicrobial agents commonly used for the treatment of infections caused by multi- resistant A. baumannii strains. Some reports indicate treatment failure due to antibiotic resistant A. baumannii strains. The aim of this study was to determine antibiotic resistance pattern and prevalence carbapenemase production in A. baumannii isolates. Method: A total of 100 A. baumannii isolates were identified from clinical specimens by standard chemical tests. The samples were collected from the patients hospitalized in two teaching hospitals of Ahvaz, southwestern of Iran. The susceptibility of isolates to different antibiotics was determined by the disk diffusion method based on Clinical Laboratory Standards Institute (CLSI) direction. The Modified Hodge Test (MHT) was performed for detection of carbapenemase - producing A. baumannii isolates. Results: The isolates showed the highest resistance to ciprofloxacin (98%). The resistance rate to cefotaxime, ceftazidime, and piperacillin was 97%, gentamicin, amikacin, and meropenem 96%, imipenem 95%, cefepime 93%, and tetracycline 60%. Most of the isolates (99%) were sensitive to colistin. Among the100 A. baumannii isolates, 53 (53%) were positive for carbapenemase production by MHT. Conclusion: This study emphasizes dissemination of carbapenem resistant A. baumannii strains. Our study also showed that the MHT has an excellent sensitivity for detecting carbapenemase - producing A. baumannii isolates.
Darioush Gharibi, Mohammad Khosravi, Zohreh Hosseini, Fatemeh Boroun, Seyedeh Kolsum Barzgar, Ali Forughi Far,
Volume 3, Issue 1 (1-2015)
Abstract
Introduction: Aloe Vera compounds have inhibitory activity on fungi, bacteria, and viruses. This study examines the antibacterial activity of A. Vera purified extracts including gel, boiled skin, boiled gel, and distilled extract against pathogenic bacteria, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Klebsiella pneumonia and Pseudomonas aeruginosa were elucidated. Method: The bacterial strains were collected from veterinary hospital. Freshly collected A. vera leaves were used for the juice extraction of gel, skin and distilled extracts. Antibacterial effects of various A. Vera extracts were evaluated using broth microdilution method. The crude polysaccharides of boiled skin extract were purified by phenol method; and fractionated by anion exchange chromatography. For each bacterium, minimum inhibitory concentration of various A. Vera extracts was determined. The protein expression changes of treated bacteria were detected by SDS-PAGE electrophoresis. Results: The distillate extract exhibited more antibacterial effects than other extracts. Out of seven-carbohydrate fractions of the skin extract, the fractions 6 and 7 had antibacterial effects on S. aureus and MRSA at 0.089 and 0.134 mg/ml, respectively; also fraction 5 showed antibacterial effects on MRSA at 0.113 mg/ml concentration. The protein profiles of these strains before and after treatment with A. Vera showed significant differences at 175, 60, 200 and 70 kDa protein bands of S. aureus, MRSA, P. aeruginosa and K. pneumonia, respectively. Conclusion: This finding showed that the distillate extract despite the minimal amount of carbohydrate and protein was more efficient against both Gram-positive and Gram negative bacteria.
Barat Ali Fakheri, Samaneh Bagheri, Nafiseh Mahdi Nezhad,
Volume 3, Issue 3 (7-2015)
Abstract
Introduction: Increasing of food-related diseases has led to the perception of diet importance. Plant-derived products (especially tea) as important sources of antioxidant and antimicrobial compounds play a major role in reducing food pathogens. In this study, total phenolic content, antioxidant and antimicrobial activity of four tea extracts including green tea, white, black and red teas were evaluated. Methods: The total phenolic amount was determined using Folin–Ciocalteu method and 1-diphenyl-2-picryl hydrazyl radical (DPPH) method was used for antioxidant activity measurement. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of tea extracts against eight species of tested bacteria (Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumonia, Saprophyticus Staphylococcus, Enterococcus faecali, Acinetobacter baumannii, Proteus mirabilis and Serratia marcescens) were evaluated by microdilution technique. Results: The results of this study showed that green tea and white tea extracts had the highest total phenolic content and antioxidant scavenging activity. Also, a strong positive correlation was observed between phenolic content and antioxidant activity in green tea and red tea. Conclusion: All four tea extracts showed inhibitions of several microorganisms. However, gram-negative bacteria were more resistant to inhibitory effects of tea extracts. As a result, non-fermented tea extracts showed more antioxidant activity and inhibition effect against tested bacteria.
Matin Saberi, Hojjatolah Zamani, Ali Salehzadeh,
Volume 3, Issue 3 (7-2015)
Abstract
Introduction: Pseudomonas aeruginosa is one of the leading causes of nosocomial infections, and antibiotic resistance of this pathogen is an important concern in treating such infections. The current work was conducted to investigate the prevalence of bla-IMP, and bla-VIM metallo-beta-lactamase (MBL) among clinical and environmental P. aeruginosa isolates obtained from ICUs of different hospitals in Rasht, Iran. Methods: A total number of 35 P. aeruginosa strains including 20 clinical and 15 environmental strains were isolated from ICUs. The isolated bacteria were screened for MBL production using Combined Disc Synergy Testing (CDST) assay. The frequency of bla-IMP and bla-VIM among MBL producing P. aeruginosa (MBL-PA) was investigated using Polymerase Chain Reaction (PCR). Also, the antibiotic susceptibility of all isolates was determined. Results: According to the results, 51% of isolates were regarded as MBL-PA while bla-IMP or bla-VIM genes were detected in 37% of isolates. The environmental isolates showed higher resistance to the majority of antibiotics compared to the clinical isolates, and MBL genes were more prevalent among environmental isolates. Conclusion: Higher resistance of environmental P. aeruginosa strains in ICUs shows a need to pursue newer approaches, including novel cleaning methods and surveillance programs, to reduce nosocomial infections.
Purimitla Usha Rani, Payala Vijayalakshmi,
Volume 4, Issue 1 (1-2016)
Abstract
Introduction: Non-fermentative Gram-negative bacilli (NFGNB) are occasionally involved in infectious diseases pathology, but have shown resistance to multiple antibiotics and the capability to gain new resistance factors in the hospital environment. The present study was aimed to investigate the antibiotic susceptibility pattern of rare NFGNB isolated from different clinical samples and the prevalence of Metallo-beta-lactamase (MBL) producing non-fermenters among the carbapenem-resistant isolates. Methods: A total of 250 clinical samples from the patients suffering from various infections were analyzed by using different standard microbiological techniques like microscopy, culture methods, biochemical reactions and antibiotic susceptibility using Kirby-Bauer method. MBL detection was performed by imipenem-EDTA combined disc test and imipenem-EDTA double disc synergy test (DDST). Results: The non-fermenters bacteria rate isolated from different clinical samples was 4.8%. The highest rate of non-fermentative isolates was observed in patients with hospital-acquired infections (91.6%). The various species of NFGNB included Pseudomonas putida (33.3%), Pseudomonas stutzeri (25%), Burkholderia cepacia (16.6%), Achromobacter xylosoxidans (16.6%) and Ochrobactrum anthropic (8.33%). The isolates showed high resistance to carbapenems, and the incidence of MBL producing non-fermenters among the carbapenem-resistant organisms was found to be 100%. Conclusion: NFGNB are now emerging as organisms of nosocomial infections. The use of broad spectrum antibiotics should be avoided, and quick detection and efficient infection control measures are essential to prevent further spread of MBLs to other Gram-negative bacilli. Detection of MBL production and rationale antibiotic usage are the most important factors which control the gradually increasing NFGNB related infections.
Alireza Milani, Marzieh Basirnejad, Sepideh Shahbazi, Azam Bolhassani,
Volume 4, Issue 1 (1-2016)
Abstract
Diagnosis of infectious diseases remains an important issue in medical science. Identification of biomarkers can be used to predict early infections. Recently, heat shock proteins (HSPs) have been known as the conserved compounds expressed under stress conditions in both prokaryotic and eukaryotic systems. These proteins act as molecular chaperones. Several studies showed the increased levels of HSPs in patients suffering from infectious diseases suggesting the role of HSPs as promising biomarkers. Also, Hsps possess significant roles in antigen presentation, the maturation of dendritic cells and the activation of lymphocytes. Thus, these proteins can be utilized to develop vaccines in bacterial and viral infections. In this mini-review, we will briefly describe the important roles of HSPs in diagnosis and immunity in bacterial and viral infections.
Hamid Sharifi, Morteza Abbasi, Sana Eybpoosh, Javad Alinejad, Hesameddin Akbarein,
Volume 4, Issue 1 (1-2016)
Abstract
Introduction: Brucellosis is a major health problem in northeast of Iran. There is not much data on the association of nutrition and lifestyle factors with the risk of brucellosis in this area. We conducted the present study to determine the risk factors of brucellosis in Khorasan-e Razavi Province, northeastern Iran. Methods: we conducted a case-control study from July 2015 to March 2016 in three cities of Khorasan-e Razavi Province. Cases and controls were recruited from individuals attending primary care and were matched together based on their age (± 2 years) and gender. Clinical and epidemiological data were collected with a valid questionnaire. Conditional logistic regression was used in Stata software V13. Results: We recruited 180 incident cases and 360 controls, of which 53.9% were male, and 90.0% were living in rural areas. Consumption of unpasteurized yogurt (OR): 5.4; 95% CI: 2.5-11.5), milk (OR: 6.0; 95% CI: 3.0-11.9), and cheese (OR = 3.7; 95% CI: 1.7-8.1), as well as engagement in livestock-related occupations (OR: 2.6; 95% CI: 1.2-5.2) significantly increased the adjusted risk of brucellosis. Conversely, having academic education (OR: 0.1; 95% CI: 0.01-0.5), consuming unpasteurized butter (OR: 0.4; 95% CI: 0.2-0.8), and timely animal vaccination (OR: 0.3; 95% CI: 0.1-0.5) had a protective effect on brucellosis. Conclusion: The risk factors identified in this study are lifestyle- and occupation- related modifiable factors. So, the disease incidence is expected to decrease in this region with modification of these risk factors, such as animal vaccination, personal protection at work, and public health education.
Mohammad Faezi Ghasemi, Fatemeh Alikhani,
Volume 4, Issue 3 (7-2016)
Abstract
Introduction: Bacteria have at least one sigma factor (σ-factor) that transcribes the genes required for cell viability. Usually, transcription of σ-factors occurs and changes in response to a variety of environmental stresses. Expression of σ-factors is one of the strategies which is used in response to different stress conditions. This study was aimed to evaluate the effects of overexpression of σ-factors genes including σA, σB, σD, σE, σF, σG, σH, σJ, σK, σL, and σM on morphology, growth pattern and biofilm formation in Mycobacterium marinum CCUG 20998. Methods: In this study, the genes for major σ-factors were cloned in the expression vector pAGHD1, containing 11 kb Hind III fragment of pAG1 and Tetz determinants. A quantitative real-time PCR (qRT-PCR) assay was used to quantify σ-factor mRNA levels of σ-factors in exponential and stationary phases. The overexpression in real-time experiments was normalized to the σA expression level. The effect of expression was evaluated on biofilm formation in this bacterium. Results: Some selected σ-factors used in this study were overexpressed. The σB had the highest expression level during the exponential and stationary phases. The σ-factors σD, σG, and σH showed lower expression level compared with σE, σF, and σK. The lowest expression belonged to σL and σM σ-factors. Also, overexpression of σE and σK led to more biofilm formation in comparison to other σ-factors in M. marinum CCUG 20998. Conclusion: The overexpression of some σ-factors can affect growth, morphology and biofilm formation in M. marinum CCUG 20998.