Polymorphisms in vitamin D receptor genes and its relation with susceptibility to brucellosis: a case-control study.

OBJECTIVE: One of the systemic infections is Brucellosis which is caused by facultative intracellular bacteria of the genus Brucella. Vitamin D is a fat-soluble prohormone, that metabolizes enzymes and its intracellular receptor creates the active hormone and also mediate in responses of immune system. METHODS: Current research consists of 102 patients with brucellosis who were selected based on culture, PCR results serology, and clinical symptoms. The control group composed of 102 healthy people. The polymorphism of genes (Bsm I, Fok I, Taq I, Apa I) encoding Vitamin D receptor (VDR) were assessed by the PCR-RFLP method. RESULTS: The results showed that ff, tt, aa, and bb genotypes in Fok I, ApaI, TaqI, and BsmI were significant in case/control groups (P-value ≤ 0.0001). The genotype frequency AA in the control group is higher than that of the study group, while genotype frequency aa in the study group is more than the control. The odds ratio for brucellosis in individuals with ff genotype is 37 times higher than that of Ff genotype. Also, the odds ratio of brucellosis in individuals with genotype tt, aa, and bb was 12, 53, and 6 times higher than those of the Aa, Bb, and Tt genotypes. CONCLUSION: The genotypes aa and ff in the positions of the ApaI and FokI are of higher importance. The brucellosis risk in individuals accompanied aa genotype at Apa I is 53 times higher than that of the genotype AA, in other words, AA and BB, TT and FF genotypes are protective against the disease.

Antimicrobial photodynamic therapy: modern technology in the treatment of wound infections in patients with burns.

BACKGROUND: Staphylococcus aureus is one of the most frequently isolated microorganisms from burn wounds. Antimicrobial photodynamic therapy (aPDT) is a new strategy that may improve antimicrobial treatment. METHOD: This study evaluated three meticillin-resistant Staphylococcus aureus (MRSA) and three meticillin-sensitive Staphylococcus aureus (MSSA) clinical isolates, which produced a biofilm with 0.1mg/ml Toluidine Blue O (TBO) (Sigma-Aldrich, Germany) with an energy density of 45J/cm2 and 90J/cm2, for MRSA and MSSA, respectively. The antibiofilm potential of aPDT with TBO was analysed using crystal violet assays and scanning electron microscopy. RESULTS: TBO-aPDT significantly degraded the biofilm formed by MRSA and MSSA clinical isolates (p<0.05). CONCLUSION: Our results indicated that aPDT is an effective approach to combat bacterial biofilms associated with burn wound infection. aPDT could provide a supplemental to the treatment of wound and tissue infection, and patients with burns may benefit from combined treatments.

Biofilm formation and antibiotic resistance in meticillin-resistant and meticillin-sensitive Staphylococcus aureus isolated from burns.

OBJECTIVE: To investigate the relationship between biofilm formation and antibiotic resistance patterns in meticillin-resistant and meticillin-sensitive Staphylococcus aureus, isolated from burns. METHODS: In a cross-sectional study, pus/wound swab samples were obtained from burns. Presence of Staphylococcus aureus was confirmed, and biofilm formation-related icaABCDR and eta, etb genes were detected by polymerase chain reaction. Biofilm formation assay was assessed using the microtiter plate method. Antibiotic resistance was performed using the disk diffusion method and minimum inhibitory concentration. RESULTS: A total of 95 patients with burns were recruited. Of the 95 wounds swabbed, Staphylococcus aureus was identified in 50 (62.5%), and 47 (94%) isolates capable of producing biofilm. Biofilm production levels were classed as 'strong' (n=29; 58%), 'moderate' (n=11; 22%), 'weak' (n=7; 14%) and 'non-biofilm forming' (n=3; 6%). There was an almost even split between isolates identified as meticillin-resistant Staphylococcus aureus (MRSA), n=24 (48%), and meticillin-sensitive Staphylococcus aureus (MSSA) n=26 (52%). The prevalence of the icaA, icaB, icaC, icaD and icaR genes among the studied isolates were 96%, 80%, 80%, 96% and 84%, respectively. The prevalence of eta and etb genes in isolates were 84% and 92%, respectively. CONCLUSION: Biofilm producing isolates of Staphylococcus aureus showed greater multidrug resistance than non-biofilm producers. In our study, a high rate of biofilm formation and antimicrobial drug resistance was seen. Our results highlight the alarming levels of antimicrobial resistance among MRSA strains and important data about the prevalence of eta and etb genes in Staphylococcus aureus strains isolated from burn patients in this study.

Spectrum of Beta-Thalassemia Mutations in Potential Carriers with Microcytic Hypochromic Anemia from Mazandaran and Golestan, Northern Provinces of Iran.

Introduction: ß-Thalassaemia is the most common genetic disorder and is considered as a major public health concern in Iran. Different countrywide studies have shown a heterogeneous mutational basis of ß-thalassaemia with different frequencies in each area. This study is aimed at investigating the common and rare mutations in Mazandaran and Golestan, northern provinces of Iran. Methods: 5425 microcytic and hypochromic individuals were investigated from Mazandaran and Golestan provinces. From these, 1323 beta carrier or affected individuals were selected where 938 persons were from Mazandaran and 385 people were from Golestan province, respectively. Result: 53 different mutations were identified, IVSII-1 (G>A) was the most common (59.14%) followed by Cd 22/23/24 (-7 bp) (5.34%), Cd 8 (-AA) (4.93%), Cd30 (G>A) (4.00%), and IVSI-5 (G>C) (3.70%) with a total of 77.11% in Mazandaran Province, respectively. In Golestan Province, IVSI-5 (G>C) was the most frequent (44.62%) followed by IVSII-1 (G>A) (27.18%), Cd 15 (TGG>TAG) (4.36%), Fr 8/9(+G) (3.85%), and Cd 8(-AA) (2.05%) with a total of 82.06%, respectively. From the 53 different mutations, 22 numbers have been observed in both provinces. Two deletions of the beta gene named Sicilian and Asian-Indian have been detected in Mazandaran with a frequency of 0.72% each. Conclusion: The 53 different mutations identified in this study were the most ever reported mutations in the country. Due to diversity of different ethnic groups, there are many varieties of mutation in beta globin gene in Iran. It could be assumed that both founder effect and natural selection caused by migration from neighboring areas have complemented each other to produce the high frequency of unique alleles within each region.

Application and development of fecal microbiota transplantation in the treatment of gastrointestinal and metabolic diseases: A review.

Fecal microbiota transplantation (FMT) restores a balanced intestinal flora, which helps to cure recurrent Clostridium difficile infections (RCDI). FMT has also been used to treat other gastrointestinal diseases, including inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), and chronic constipation, as well as a variety of non-GI disorders. The purpose of this review is to discuss gut microbiota and FMT treatment of GI and non-GI diseases. An imbalanced gut microbiota is known to predispose one to Clostridium difficile infections (CDI), IBD, and IBS. However, the complex role of the gut microbiota in maintaining health is a newer concept that is being increasingly studied. The microbiome plays a major role in cellular immunity and metabolism and has been implicated in the pathogenesis of non-GI autoimmune diseases, chronic fatigue syndrome, obesity, and even some neuropsychiatric disorders. Many recent studies have reported that viral gastroenteritis can affect intestinal epithelial cells, and SARS-CoV-2 virus has been identified in the stool of infected patients. FMT is a highly effective cure for RCDI, but a better understanding of the gut microbiota in maintaining health and controlled studies of FMT in a variety of conditions are needed before FMT can be accepted and used clinically.

Assessment of knowledge, attitudes, and practice regarding antibiotic self-treatment use among COVID-19 patients.

Background: Self-medication with antibiotics is a common practice across different age groups and different cultures that can cause problems such as drug resistance, side effects, and rising costs for the healthcare system community. During the coronavirus pandemic (COVID-19), people with mild symptoms have avoided seeing a doctor, preferring to self-medicate. The impact of self-medication in COVID-19 patients is an important public health issue. The aim of this study was to evaluate the knowledge of, attitudes toward, and performance of self-medication with antibiotics in COVID-19 patients. Methods: This cross-sectional study was conducted among patients with COVID-19. Participants were selected by random sampling. A survey of knowledge, attitude and practice of taking antibiotics in patients with COVID-19 was conducted. Data were analyzed using SPSS version 22 software. Results: The prevalence of self-medication with antibiotics in patients with COVID-19 was 56.1%. Most COVID-19 patients have the overall knowledge, attitude and practice score of self-medication with antibiotics. There was a significant difference between the knowledge and attitudes of educated and uneducated patients (p<0.01). Of the demographic variables, there was no significant difference between sexes in terms of attitude and practice of antibiotic self-medication in COVID-19 patients (p>0.05). Conclusion: Considering the high prevalence of antibiotic self-medication in COVID-19 patients, it is recommended to provide the necessary education and practical means of reducing the amount of antibiotic self-medication.

Linezolid resistance in multidrug-resistant mycobacterium tuberculosis: A systematic review and meta-analysis.

Introduction: Linezolid (LNZ) is an effective antibiotic to treat patients with multidrug-resistant tuberculosis (MDR-TB) treatment failure. M. tuberculosis strains resistant to isoniazid and rifampin are defined as MDR-TB. In recent years, resistance to LNZ among MDR-TB cases has been reported in several different countries. In this study, we performed a systematic review and meta-analysis to investigate the prevalence of LNZ resistance among MDR-TB isolates. Methods: The databases of Embase, PubMed/Medline, and Web of Science were searched systematically from January 2000 to April 2021. Statistical analyses were performed by using Comprehensive Meta-Analysis software. Heterogeneity was reported by using the t-squared statistic and Q-statistic. Begg's rank correlation in combination with the funnel plot were used to evaluate any possible publication bias. Results: In total, 25 studies were selected for meta-analysis from 14 different countries; the majority was from China (n = 5) and Turkey (n = 4). Moreover, 7,366 patients were infected with MDR M. tuberculosis. Among the study population, 98 patients were co-infected with HIV, and 18 patients with hepatitis C virus (HCV). Furthermore, 28 cases had diabetes, and139 cases were alcohol abuser. Overall, 4,956 MDR M. tuberculosis strains were isolated from TB patients. The pooled frequency of LNZ resistance among the clinical isolates of MDR M. tuberculosis was 4.2% (95%). Begg's (p = 0.72) test showed no evidence of publication bias. Conclusion: LNZ resistance among MDR M. tuberculosis isolates is increasing. On the other hand, long-term treatment of MDR-TB cases with LNZ alone is associated with several adverse effects. Thus, it is recommended that newer anti-TB drugs, including bedaquiline and delamanid, in combination with linezolid could increase its effectiveness and decrease toxicities. However, more studies should be done in this field.

Bacterial co-infections and antibiotic resistance in patients with COVID-19.

Background: Bacterial co-infections are frequently identified in viral respiratory infections and are significant reasons for morbidity and mortality. Information on the prevalence of bacterial co-infection in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is lacking. The purpose of this study was to determine the prevalence of bacterial infections and antibiotic resistance in patients with coronavirus disease (COVID-19). Methods: In a cross-sectional study, blood culture (BC) and endotracheal aspirate (ETA) were obtained from COVID-19 patients (RT-PCR positive for SARS-CoV-2). The bacterial isolates were confirmed by the standard microbiological methods. Antibiotic resistance was determined using the disk diffusion method. Results: Among these 340 patients with COVID-19, a total of 43 (12.46%) patients had secondary bacterial infections. The most common bacteria isolated through ETA and BC included Klebsiella species 11 (25.59%), methicillin-sensitive Staphylococcus aureus (MSSA) 9 (20.93%), Escherichia coli 7 (16.28%), methicillin-resistant Staph ylo coccus aureus (MRSA) 6 (13.95%), Enterobacter species 5 (11.63%), Streptococcus pneumoniae 1 (2.32%), and Pseudomonas aeruginosa 4 (9.30%). The results showed that Enterobacteriaceae isolates from COVID-19 patients had the highest resistance to cotrimoxazole (74%), piperacillin (67.5%), ceftazidime (47.5%), and cefepime (42.5%). All isolates were susceptible to amikacin (100%). S. aureus isolates were susceptible to vancomycin (100%) and the rates of resistance to oxacillin, erythromycin and clindamycin were over (90%). P. aeruginosa was susceptible (90%) to imipenem. Conclusions: Bacterial co-infection is relatively infrequent in hospitalized COVID-19 patients. According to the results, one of the causes of death of these patients could be a secondary infections.

Effect of glutathione-stabilized silver nanoparticles on expression of las I and las R of the genes in Pseudomonas aeruginosa strains.

BACKGROUND: Biofilm formation is regarded as a significant factor in the establishment of infections caused by Pseudomonas aeruginosa. P. aeruginosa is one of the most important causes of nosocomial infections. Today silver nanoparticles (Ag-NPs) are used as antimicrobials due to their well-known, chemical, biological, and physical properties. Exposure to nanoparticles could inhibit colonization of new bacteria onto the biofilm. METHODS: In the present work, the green synthesis of Ag-NPs was performed using the alcoholic extract of Eucalyptus camaldulensis. Ag-NPs and glutathione-stabilized silver nanoparticles (GSH-Ag-NPs) were characterized using X-ray diffraction (XRD), dynamic light scattering (DLS), scanning electron microscope (SEM), and carbon, nitrogen, and hydrogen (CNH) and Fourier transform infrared spectroscopy (FTIR) techniques were applied to investigate the structure of the modified nanoparticles. Then, the antimicrobial and antibiofilm potential of the prepared Ag-NPs and GSH-Ag-NPs against P. aeruginosa strains was evaluated using microbroth dilution method and their effects on the expression of las I and las R genes. RESULTS: In this study, a total of 50 P. aeruginosa isolates were recovered from clinical samples. According to the results, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) value of Ag-NPs against P. aeruginosa was determined to be 512-256 µg/ml, respectively, while the MIC and MBC value of GS-Ag-NPs against P. aeruginosa clinical strains was determined in a range of 128-256 µg/ml and 256-512 µg/ml, respectively. The mean expression level in las R, las I genes in P. aeruginosa strains treated with ½ MIC of Ag-NPs was decreased by -5.7 and -8fold, respectively. The mean expression levels of las R, las I genes in P. aeruginosa strains treated with ½ MIC of GS-Ag-NPs were decreased by -8.7 and -10fold, respectively (P < 0.05). CONCLUSIONS: The results of our study showed that Ag-NPs and GS-Ag-NPs are highly effective against P. aeruginosa strains. Moreover, this study also proves the promising potential of using nanoparticles as anti-biofilm formation and antibacterial agents.

Synergistic antimicrobial activity of melittin with clindamycin on the expression of encoding exfoliative toxin in Staphylococcus aureus.

Staphylococcus aureus is an opportunistic human pathogens, with the ability to produce a series of virulence factors that contribute to the severity of infections. Exfoliative toxins (ETs) are one of the important virulence factors that participating in staphylococcal scalded skin syndrome. Melittin has different biological activities, comprising of antiviral, broad spectrum antibacterial, antiprotozoal, antifungal and anti-inflammatory effects. Twelve clinical isolates of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) were obtained from wound infection in the burn patients. The MIC plus three sub-inhibitory concentrations (I, II and III) of clindamycin and melittin were tested. Next, the synergistic effects of melittin and clindamycin were evaluated using the broth microdilution checkerboard assay. The detection of exfoliative toxin A and B genes were examined by PCR method. Then the effects of sub-MIC melittin on the expression levels of eta and etb were assessed by quantitative real-time PCR (qRT-PCR) assay. Melittin MIC values against MRSA and MSSA planktonic cells were 0.25-0.5 and 0.25-1 µg/ml, respectively. The clindamycin MIC values against MRSA and MSSA were between 0.5 and 8 µg/ml and 0.5-2 µg/ml, respectively. The results of the time-kill kinetics assay (3.5log10 and 3log10) against MSSA and MRSA planktonic cells were determined within 24 h using melittin. The mean expression of eta in MRSA and MSSA was significantly downregulated to approximately 3.5 and 4 fold, respectively. Moreover, the mean expression of etb in MRSA and MSSA were significantly downregulated to approximately 2.5 and 3 fold, respectively. Hemolytic assay showed that the extracted melittin indicates a strong hemolytic activity (HD50 = 2 µg/ml). Melittin at 0.5 µg/ml induced cell lysis and stimulated the formation of vesicles in S. aureus strains. Melittin could reduce the expression of eta and etb as encoding exfoliative toxin A and B genes. This component appears to be a good candidate for the treatment of MRSA and MSSA strains. So, melittin in combination with clindamycin can be classified as a complementary treatment of wound infections in burn patients.

Distribution of Iron Uptake Systems Encoding Genes Among the Clinical Isolates of Escherichia coli Compared to Foodstuffs Isolates.

INTRODUCTION: Bacteria require iron ions to grow and infect the host, which, by using iron uptake systems, acquire free iron from their host cell. Escherichia coli is one of the most important pathogens to cause food poisoning and clinical infections. The aim of this study was to assess the distribution of iron uptake systems encoding genes in clinical isolates of E.coli compared to food samples isolates. MATERIALS AND METHODS: This investigation was conducted to determine the prevalence of E. coli isolated from various sources of food and clinical specimens. The E. coli isolates confirmed by the standard microbiological methods. The isolates were examined for the presence of iut A and iuc A genes by specific primers using the polymerase chain reaction technique. RESULTS: A total of 100 and 50 isolates of E. coli were collected from clinical samples and foodstuffs, respectively. The prevalence of E. coli in the food and clinical samples was 33.33% and 64.10%, respectively. The frequency of iut A and iuc A genes in the food and clinical isolates were 76%-84% and 86% - 83%, respectively. CONCLUSION: Our results showed that the prevalence of E. coli isolates with iut A and iuc A genes was relatively higher compared to many previous studies. The existence of these genes in E. coli strains is likely to be related to pathogenicity in those strains, which requires further studies in the future.

Potentiation effects of antimicrobial photodynamic therapy on quorum sensing genes expression: A promising treatment for multi-species bacterial biofilms in burn wound infections.

BACKGROUND: As the increase in the prevalence of antimicrobial resistant bacterial strains, development of adjuvant antimicrobial approach for the treatment of burn wound infection is important. Therefore, the aim of this study was to assess the effectiveness of antimicrobial photodynamic therapy (aPDT) using indocyanine green (ICG) in reducing the bacterial load and expression profiling of the quorum sensing (QS) system associated with the biofilm formation in multi-species bacterial biofilms. MATERIALS AND METHODS: Multi-species bacterial suspension including Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus were photosensitized with ICG, which was excited at a wavelength of 810 nm. After evaluating the dose of ICG-aPDT contributing to the sub-significant reduction of colony forming unit (CFU)/mL, the gene expression levels of abaI, agrA, and lasI were assessed using real-time quantitative reverse transcription polymerase chain reaction. As well as, lipid peroxidation, superoxide radicals and reactive oxygen species (ROS) were measured and the morphological changes of multi-species bacteria were evaluated by scanning electron microscopy (SEM). RESULTS: According to the results, maximal sub-significant reduction dose of aPDT against CFUs/mL of multi-species bacterial cells was found with a combination of 31.2 µg/mL of ICG and irradiation by the diode laser for 1 min, with an estimated average output light energy 31.2 J/cm2. The expression levels of abaI, agrA, and lasI in A. baumannii, P. aeruginosa, and S. aureus were down-regulated to approximately 1.9-, 3.7-, and 4.9-fold, respectively. The amount of lipid peroxidation, superoxide radical production, and ROS generation significantly increased (P < 0.05). Also, the cell morphology under SEM showed that ICG-aPDT is a stressful condition for multi-species bacterial cells. CONCLUSIONS: ICG-aPDT with antimicrobial, anti-biofilm, and gene expression inhibitor characteristics, as well as, ROS generation can be used for the treatment of burn wound infections in vivo.

Detection of Virulence Factors and Antibiotic Resistance Pattern of Clinical and Intensive Care Unit Environmental Isolates of Pseudomonas aeruginosa.

BACKGROUND: Pseudomonas aeruginosa is a gram-negative non-glucose fermenting aerobic bacteria and an opportunistic pathogen in humans and animals. The present study was carried out to investigate the distribution of virulence factors and antibiotic resistance properties of P. aeruginosa isolated from patients and intensive care unit (ICU) environment. MATERIAL AND METHODS: A total of 116 P. aeruginosa isolated from patients and ICU environment were collected from Besat hospital in Hamadan, the West of Iran. P. aeruginosa isolates were analyzed based on the presence of the virulence factors encoding genes included exoA, exoS, exoU, and algD using polymerase chain reaction (PCR). Antimicrobial susceptibility test was performed using a disk diffusion method. RESULTS: The results showed the prevalence of exoA 33 (56.9%), exoS 21 (36.20%), exoU 37 (63.8%), and algD 35 (60.34%) genes in ICU environment P. aeruginosa strains and exo A 23 (39.25%), exoS 25 (43.1%), exoU 40(68.98%), and algD 25 (43.1%) genes in clinical isolates of P. aeruginosa. High resistance levels of the clinical and ICU environment isolate to ampicillinsulbactam (100%), were also observed. CONCLUSION: Our findings should raise awareness about antibiotic resistance in hospitalized patients in Iran. Clinicians should exercise caution in prescribing antibiotics, especially in cases of human infections.

Identification of Quinolone and Colistin Resistance Genes in Escherichia Coli Strains Isolated from Mucosal Samples of Patients with Colorectal Cancer and Healthy Subjects.

INTRODUCTION: Antibiotic resistance and extensive use of antibiotics are amongst the major causes of failure in antibiotic treatment. The purpose of this study was to investigate antibiotic resistance patterns and to identify resistance genes of quinolones and colistin in Escherichia coli. There are a very few patents on E. coli isolated from colorectal cancer. So, this study demonstrates that some bacteria resistant to ciprofloxacin have not resistance genes.Moreover, new patterns for E. coli are presented for isolates of patients with colorectal cancer. MATERIALS AND METHODS: Of the three healthy people, inflammatory bowel diseases (IBD) patients and colorectal cancer patients, 40 E. coli strains isolated after confirmation by biochemical and molecular methods. The susceptibility of isolates to antibiotics was investigated using disk diffusion test. After deoxyribonucleic acid (DNA) extraction, polymerase chain reaction (PCR) was used to identify genes encoding resistance to ciprofloxacin (qnr A, qnr B) and colistin (mcr-1). RESULTS: The results showed that E. coli isolates from colorectal cancer patients had the highest resistance to piperacillin (67.5%), ceftazidime (47.5%), and cefepime (42.5%). Also, E. coli strains isolated from IBD patients showed resistance to antibiotic ceftazidime 13%. More than 95% of E. coli strains isolated from healthy people were susceptible to antibiotics. Based on the results, 18 (15%) E. coli strains showed resistance to ciprofloxacin. The qnr A gene was detected in 61.11% isolates; however, qnr B was detected in 9 (50%) isolates. Isolates resistant to colistin were not observed. CONCLUSION: These findings indicate increased resistance of E. coli to ciprofloxacin in comparison with prior studies. Further research in this field will increase our knowledge and more effective exposure to the antibiotic resistance of the pathogenic microorganisms.

Antibiotic resistance pattern and phylogenetic groups of the uropathogenic Escherichia coli isolates from urinary tract infections in Hamedan, west of Iran.

BACKGROUND AND OBJECTIVES: Escherichia coli is the most common causative agent of urinary tract infections (UTIs) in 90-80% of patients in all age groups. Phylogenetic groups of these bacteria are variable and the most known groups are A, B1, B2 and D. The present study aimed to evaluate the phylogenetic groups of E. coli samples obtained from UTIs and their relation with antibiotic resistance patterns of isolates. MATERIALS AND METHODS: In this study 113 E. coli isolates were isolated from distinct patients with UTIs referred to Hamadan hospitals. After biochemical and molecular identification of the isolates, typing and phylogenetic grouping of E. coli strains were performed using multiplex PCR targeting chu, yjaA and TSPE4.C2 genes. The anti-microbial susceptibility of the isolates to amikacin, ampicillin, trimethoprim-sulfamethoxazole, amoxicillin/clavulanic acid, ciprofloxacin, cefotaxime, imipenem, aztreonam, gentamicin, meropenem, nitrofurantoin, nalidixic acid and cefazolin was determined using disk diffusion method. RESULTS: Of 113 isolates, 50 (44.2%), 35 (31%), 23 (20.4%) and 5 (4.4%) of samples belonged to group B2, group D, group A and group B1 phylogenetic groups respectively. All isolates were susceptible to meropenem, imipenem (100%), followed by amikacin (99.1%). The highest resistance rates were observed against ampicillin (74.3%) and nalidixic acid (70.8%). Correlation between phylogenetic groups and antibiotic susceptibilities was significant only with co-amoxiclav (P = 0.006), which had the highest resistance in phylogenetic group A. CONCLUSION: Prevalence of different phylogroup and resistance associated with them in E. coli samples could be variable in each region. Therefore, investigating of these items in E. coli infections, could be more helpful in selecting the appropriate antibiotic treatment and epidemiological studies.

Detection of adeABC efllux pump encoding genes and antimicrobial effect of Mentha longifolia and Menthol on MICs of imipenem and ciprofloxacin in clinical isolates of Acinetobacter baumannii.

BACKGROUND: Acinetobacter baumannii is an opportunistic pathogen that causes nosocomial infections especially in patients in intensive care units (ICUs). Accordingly, the aim of our study was to detection of adeABC efllux pump encoding genes and antimicrobial effect of the essential oil of Mentha longifolia and Menthol on the minimum inhibitory concentration (MIC) of imipenem and ciprofloxacin in clinical isolates of A. baumannii. METHODS: A total of 75 clinical isolates of A. baumannii were collected. The presence of efflux pump genes was detected by polymerase chain reaction (PCR). The minimum inhibitory concentration (MIC) of the essential oil of Mentha longifolia and Menthol and their combined effect with antibiotics were measured by microbroth dilution method and fractional inhibitory concentration (FIC) index. RESULTS: The frequency of adeA, adeB, and adeC genes in clinical isolates of A. baumannii were 86.7, 90.7, and 92%, respectively. When the essential oil of Mentha longifolia was combined with ciprofloxacin and imipenem, MICs decreased 4- and 8-fold, respectively. In the combination of menthol with imipenem, the resistance to imipenem was reduced from 0- to 16-fold in 90% (63/70) of the isolates. CONCLUSION: The presence of efflux pump genes in more than 90% of A. baumannii isolates indicates its potential role in inducing imipenem- and ciprofloxacin-resistance in this bacterium. Menthol has an antimicrobial effect as an active ingredient in Mentha longifolia. In the future, the combination of medicinal plants with antibiotics can be used as a complement in treating diseases caused by drug-resistant bacteria such as A. baumannii infections.

The effect of antimicrobial photodynamic therapy on the expression of biofilm associated genes in Staphylococcus aureus strains isolated from wound infections in burn patients.

PURPOSE: Burn patients are particularly susceptible to microbial infection. Staphylococcus aureus causes burn wound, impetigo and cellulitis. Although sub-lethal antimicrobial photodynamic therapy (aPDT) would not result in microorganism killing, it can considerably influence microbial virulence factor. METHODS: Twelve methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) isolated from burns patients. To determine the sub-lethal dose of aPDT, 12 clinical isolates of S. aureus photosensitized with 100 µg ml -1 toluidine blue O (TBO) and irradiated by light emitting diode (LED) with a wavelength of 630 ± 10 nm and energy densities of 52.0, 104.1, and 156.2 J/cm2, then bacterial viability was measured. The effects of sub-lethal aPDT on the expression levels of ica ABCD and ica R genes were assessed by quantitative Real-time PCR (qRT-PCR) method. RESULT: Fifty and 100 µg ml-1 of TBO significantly reduced the mean cell survival in the MRSA (2.5 - 3 log10) and MSSA (2.75-3.1 log10) isolates. The average expression levels of icaA, ica B, ica C, and ica D in the MRSA and MSSA isolates were decreased by (12, 14, 11, and 9) and (13, 14.5, 12, and 9.5) fold change, respectively (P < 0.05). However, the expression of ica R gene was decreased by 6 and 8 folds change in MRSA and MSSA, respectively. CONCLUSION: The potential of TBO-mediated aPDT could reduce the expression of ica ABCD as important genes involved in biofilm formation and ica R gene as a repressor of the ica operon. Therefore, the use of aPDT agents as a complementary therapy in wound infections of burn patients is recommended.

Evaluation of TNF-α cytokine production in patients with tuberculosis compared to healthy people.

Background: Mycobacterium tuberculosis (TB) is one of the most important causes of human mortality. Approximately one-third of the world's population is infected with TB and 5-10% of them develop the active form of the disease. Cytokines play a major role in the host defense process against Mycobacterium infections. Among these cytokines, tumor necrosis factor alpha (TNF-α) has a prominent role in the defense of and pathological responses to tuberculosis. Materials and methods: A case-control study was carried out from May 2016 to June 2017. 45 patients with diagnosis of tuberculosis (smear and positive culture) were included as case group and 45 healthy subjects as control group. The serum levels of TNF-α were determined with the enzyme-linked immunosorbent assay (ELISA) method. Results: The concentration of TNF-α in patients with TB was significantly higher than in the control group (P<0.05). However, the difference was only significant in the age groups 20-30 and 50-60 years; in the age groups 30-40, 40-50 and 50-70 years, the difference was not significant, although certain trends were apparent. Discussion and conclusion: Since the level of serum TNF-α is higher in patients with pulmonary tuberculosis than in individuals without it, the measurement of TNF-α levels can be useful as a probable marker for the diagnosis of tuberculosis.

Antimicrobial Photodynamic Therapy: An Effective Alternative Approach to Control Bacterial Infections.

Introduction: The purpose of this review was to evaluate the available literature for in vitro and in vivo effectiveness of antimicrobial Photodynamic therapy (aPDT) in the field of bacteriology. Methods: A review of the relevant articles carried out in PubMed and Scopus to determine the efficiency of aPDT used in the reduction of microbial infection. Thirty-one relevant documents retrieved from PubMed, Scopus by inserting "antimicrobial photodynamic therapy" and "bacterial infection" and "photodynamic therapy" keywords. Results: According to different results, aPDT can be used as an adjuvant for the treatment of infectious diseases. The use of photosensitizer methylene blue, toluidine blue O (TBO), indocyanine green with light diode laser centered at (630±10 nm) and (650±10 nm) wavelengths have been shown to have significant results for the treatment of infectious diseases and bactericidal properties Conclusion: These findings suggest that, aPDT can be an efficient method in the treatment of localized and superficial infections.

Antimicrobial inhibitory activity of aqueous, hydroalcoholic and alcoholic extracts of leaves and stem of Daphne mucronata on growth of oral bacteria.

Background: Plants are a source of potential anti-infective agents. Daphne mucronata is a shrub in the family Thymelaeaceae, which has therapeutic effects. The aim of the present study was to evaluate the antimicrobial activity of aqueous, hydroalcoholic and alcoholic extracts of the leaves and stem of Daphne mucronata on the growth of oral bacteria. Materials and methods: Leaves and stem of Daphne mucronata were collected from the Zagros Mountains, Lorestan, Iran. They were air dried in the shade. Aqueous, hydroalcoholic and alcoholic extracts of Daphne mucronata were made by using classic techniques for solvent extraction of plant material. The antimicrobial effects of the Daphne mucronata extracts were evaluated using the agar disk diffusion method (ADDM) and the minimum inhibitory concentration (MIC). The data were analyzed using Duncan's test and ANOVA. Results: The results showed that the antimicrobial activity depended on the type of extract. The alcoholic extract of Daphne mucronata had the highest antibacterial activity and the highest effect on Streptococcus mutans. The aqueous extract of the plant had no effect on bacterial growth. Conclusion: On the basis of the current results, the alcoholic extract of Daphne mucronata might be promising as a natural antimicrobial agent and as a medicine for the prevention and control of the growth of Streptococcus mutans.