Evaluation of Staphylococcus Aureus and Pseudomonas Aeruginosa in Saliva of Patients with Acute Myeloid Leukemia.

​Statement of the Problem: Patients with leukemia are prone to infectious and often life-threatening complications. Evidence suggests that a specific oral microbiota may contribute to septicemia, which can delay antineoplastic treatment, compromise treatment efficacy, or even endanger patients' lives. Purpose: This study investigated the prevalence of Staphylococcus aureus and Pseudomonas aeruginosa in the saliva of patients with acute myeloid leukemia who were candidates for bone marrow transplantation. Materials and Method: This cross-sectional study was conducted in 2019 in the Hematology-Oncology Department of Namazi Hospital, Shiraz University of Medical Sciences. The study included 28 patients with acute myeloid leukemia eligible for bone marrow transplantation as the case group and age- and sex-matched healthy individuals as the control group. Unstimulated saliva samples were collected to determine the frequency of Staphylococcus aureus and Pseudomonas aeruginosa. Data were analyzed using SPSS version 18, the chi-square test, and the independent t-test. Results: In the patients with acute myeloid leukemia, 26 (86%) were positive for Staph-ylococcus aureus and 18 (60%) were positive for Pseudomonas aeruginosa. In the healthy group, 11 (22.9%) were positive for Staphylococcus aureus and 3 (6.2%) were positive for Pseudomonas aeruginosa. The frequency of Pseudomonas aeruginosa and Staphylococcus aureus in the saliva samples of patients with acute myeloid leukemia was significantly higher than in the healthy control subjects (p value < 0.05). Chi-square test showed no significant association between age and the frequency of bacteria (p value= 0.27). Conclusion: In the current study, the frequency of Staphylococcus aureus and Pseudomonas aeruginosa in the saliva of patients with acute myeloid leukemia was higher than in the healthy control group.

Development of antibacterial collagen membranes with optimal silver nanoparticle content for periodontal regeneration.

The effective control of pathogenic bacteria is crucial in the restoration of periodontal tissue affected by periodontitis. Guided tissue regeneration (GTR) membranes are commonly used to aid in the repair of periodontal defects. Therefore, there is a clear advantage in developing antibacterial periodontal membranes that can effectively eliminate infections and promote tissue regeneration. This study aimed to create a collagen membrane with optimal content of silver nanoparticles (AgNPs) for effective antibacterial properties and minimal toxicity to mammalian cells. Ascorbic acid-reduced AgNPs were incorporated into collagen at the ratio of 0.5%, 1%, 2%, and 3% (based on total dry weight). Collagen/AgNPs hydrogels were compressed and freeze-dried to form membranes and then were characterized. Antibacterial activity was tested against Fusobacterium nucleatum and Enterococcus faecalis, and membrane cytocompatibility was accomplished on human gingival fibroblasts. Membranes with 2% and 3% AgNPs exhibited significant antibacterial activity, while 1% showed minimal activity and 0.5% and 0% showed none. HGF cells on the 3% AgNPs membrane had poor viability, proliferation, and adhesion, but 0%, 0.5%, 1%, and 2% AgNPs membranes showed desirable cellular behavior. In conclusion, the collagen membrane with 2% AgNPs demonstrated both antibacterial capacity and excellent cytocompatibility, making it a promising choice for periodontal treatments, especially in GTR approaches.

Determining the cytotoxicity of the Minimum Inhibitory Concentration (MIC) of silver and zinc oxide nanoparticles in ESBL and carbapenemase producing Proteus mirabilis isolated from clinical samples in Shiraz, Southwest Iran.

OBJECTIVE: Proteus mirabilis is related to serious infections. The present study was designed to investigate the minimum inhibitory concentration (MIC) of silver nanoparticles (AgNPs) and zinc oxide nanoparticles (ZnONPs) and cytotoxicity among P. mirabilis isolates recovered from clinical samples in Shiraz. RESULTS: A total of 100 P. mirabilis isolates were screened by biochemical tests and polymerase chain reaction (PCR). Also, 25 (25%) and 7 (7%) isolates were positive for extended-spectrum beta-lactamase (ESBLs) and carbapenemase, respectively. Synthesized nanoparticles were characterized by UV-vis spectrum, X-ray diffraction (XRD), and electron microscopy. The average size of AgNPs and ZnONPs in the present study is 48 and < 70 nm, respectively. The MIC and the MBC of the ZnONPs were in the range of 31.25 µg/ml and 62.5 µg/mL, respectively. Also, for AgNPs, the MIC and the MBC were in the range of 7.8 µg/mL and 15.6 µg/mL, respectively. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay in a primary culture of fibroblast L929 cells for this MIC indicated biocompatibility and low cytotoxicity of Ag NPs and for ZnONPs indicated significant cytotoxicity. Also, a MIC of AgNPs can be used as a therapeutic concentration without the effect of cytotoxicity in human cells.

Evaluation of aminoglycoside modifying enzymes, SCCmec, coagulase gene and PCR-RFLP coagulase gene typing of Staphylococcus aureus isolates from hospitals in Shiraz, southwest of Iran.

Staphylococcus aureus is an important human pathogen that causes various infections. Aminoglycosides are broad-spectrum antibiotics used to treat methicillinresistant S. aureus (MRSA) infections. Typing of S. aureus isolates by coagulase gene typing and PCR-RFLP coa gene is a fast and suitable method for epidemiological studies. Aim of the present study was to evaluate the resistance to aminoglycosides, staphylococcal chromosomal cassette mec (SCCmec) types, coagulation typing and PCR-RFLP coa gene in clinical isolates of S. aureus. 192 S. aureus isolates were collected from Namazi and Shahid Faghihi hospitals. Antibiotic resistance was measured by disk diffusion method and MIC was determined for gentamicin. The presence of genes encoding aminoglycoside modifying enzymes (AME) and mecA gene were assessed by PCR. Also the coagulase typing, PCR-RFLP coa gene, and SCCmec typing were performed. Out of 192 isolated S. aureus isolates, 83 (43.2%) MRSA isolates were identified. In this study, a high resistance to streptomycin and gentamicin (98.7%) were observed. Among the AME genes, the aac (6')-Ie-aph (2″) gene was the most common. Based on the SCCmec typing, it was determined that the prevalence of SCCmec type III (45.8%) was highest. From the amplification of the coa gene, 5 different types were obtained. Also, in digestion of coa gene products by HaeIII enzyme, 10 different RFLP patterns were observed. According to this study, aminoglycoside resistance is increasing among MRSA isolates. As a result, monitoring and control of aminoglycoside resistance can be effective in the treatment of MRSA isolates. Also, typing of S. aureus isolates based on coagulase gene polymorphism is a suitable method for epidemiological studies.

Emergence of K1 ST23 and K2 ST65 hypervirulent klebsiella pneumoniae as true pathogens with specific virulence genes in cryptogenic pyogenic liver abscesses Shiraz Iran.

Hypervirulent Klebsiella pneumoniae (hvKp) pathotype is emerging worldwide in pyogenic liver abscesses (PLAs). However, the role of virulence factors in pathogenicity remains unclear. On the other hand, the epidemiology of PLAs in Iran is unknown. From July 2020 to April 2022, bacterial species were isolated and identified from the drainage samples of 54 patients with PLAs. K. pneumoniae as the most common pathogen of pyogenic liver abscesses was identified in 20 (37%) of the 54 patients. We analyzed the clinical and microbiological characteristics of K. pneumoniae-related pyogenic liver abscesses. Antibiotic susceptibility testes and string test were performed. 16S rRNA, antibiotic resistance, and virulence genes were determined by polymerase chain reaction amplification. Clonal relatedness of isolates was identified by multilocus sequence typing. Virulence levels were assessed in the Galleria mellonella larval infection model. Four hvKp isolates (K1/K2) were found to be responsible for cryptogenic PLAs, and 16 classical K. pneumoniae isolates (non-K1/K2) were associated with non-cryptogenic PLAs. Three capsular serotype K1 strains belonged to sequence type 23 (ST23) and one K2 strain to ST65. Meanwhile, the non-K1/K2 strains belonged to other STs. ST231 was the most common strain among the classical K. pneumoniae strains. Compared with the non-K1/K2 strains, capsular serotypes K1/K2 strains were less resistant to antibiotics, had positive string test results, and had more virulence genes. In Galleria mellonella, a concentration of 106 colony-forming units of the K1 hvKp strain resulted in 100% death at 24 hours, confirming the higher virulence of the hvKp strain compared with cKp. K. pneumoniae isolates represented that the acquisition of any plasmid or chromosomal virulence genes contributes to pathogenicity and high prevalence in PLAs. Meanwhile, hvKp isolates with a specific genetic background were detected in cryptogenic PLAs.

The Spread of Insertion Sequences Element and Transposons in Carbapenem Resistant Acinetobacter baumannii in a Hospital Setting in Southwestern Iran.

BACKGROUND: Acinetobacter baumannii is one of the most important hospital pathogenic bacteria that cause infectious diseases. The present study aimed to determine the frequency of carbapenem resistance genes in association with transposable elements and molecular typing of carbapenem-resistant A. baumannii bacteria collected from patients in Shiraz, Iran. MATERIALS AND METHODS: A total of 170 carbapenem-resistant A. baumannii isolates were obtained from different clinical specimens in two hospitals. The minimum inhibitory concentrations (MIC) of imipenem were determined and the prevalence of OXA Carbapenemases, Metallo-ß-lactamases genes, insertion sequences (IS) elements, and transposons were evaluated by the polymerase chain reaction (PCR) method. Finally, molecular typing of the isolates was performed by the Enterobacterial Repetitive Intergenic Consensus-PCR method. RESULTS: The MICs ranged from 16 to 1,024 µg/mL for imipenem-resistant A. baumannii isolates. Out of the 170 carbapenem resistant A. baumannii isolates, blaOXA-24-like (94, 55.3%) followed by blaOXA-23-like (71, 41.7%) were predominant. In addition, A. baumannii isolates carried blaVIM (71, 41.7%), blaGES (32, 18.8%), blaSPM (4, 2.3%), and blaKPC (1, 0.6%). Moreover, ISAba1 (94.2%) and Tn2009 (39.2%) were the most frequent transposable elements. Furthermore, (71, 44.0%) and (161, 94.7%) of the ISAba1 of the isolates were associated with blaOXA-23 and blaOXA-51 genes, respectively. Besides (3, 1.7%), (1, 0.6%) and (5, 2.9%) of blaOXA-23 were associated with IS18, ISAba4, and ISAba2, respectively. Considering an 80.0% cut off, clusters and four singletons were detected. CONCLUSION: According to the results, transposable elements played an important role in the development of resistance genes and resistance to carbapenems. The results also indicated carbapenem-resistant A. baumannii bacteria as a public health concern.

Molecular diversity survey on diarrheagenic Escherichia coli isolates among children with gastroenteritis in Fars, Iran.

Aim: To differentiate Escherichia coli isolates from diarrheal pediatric patients in clinical laboratories. Materials & methods: Patients with watery diarrhea were selected for sampling and tested for diarrheagenic E. coli (DEC) by API kit. DEC isolates were tested for phylotyping, pathotyping and presence of determined virulence-encoding genes by specific molecular methods. Results: About 50% of isolates were detected as DECs (>55 and >31% were categorized B2 and D phylotypes respectively). Enterotoxigenic E. coli was the most and enteroinvasive E. coli was the lowest prevalent pathotypes. csg and fim genes were the most present virulence factors. Conclusion: Typing of E. coli isolates from stool specimens will help to determine the diversity of diarrheal pathogens and take proper decisions to reduce the health burden of diarrheal diseases.

Isolation and Identification of Non- Commensal Pathogenic Bacteria in the Saliva of Patients Candidate for Liver Transplant: A Cross Sectional Study in Shiraz, South of Iran.

STATEMENT OF THE PROBLEM: Liver cirrhosis is the end stage of liver failure. It is mentioned as one of the main etiologies of morbidity and mortality in the world. The human salivary bacteria may induce oral disorders and interact with other body microbiota. PURPOSE: The aim of the present study is to identify the pathogenic bacteria of non-oral origin from the saliva samples of patients with end stage liver failure. MATERIALS AND METHOD: In this cross-sectional study, the saliva samples of 88 end stage liver disease cases and 84 age- and sex-matched healthy subjects were collected. The samples were cultured using gram staining and API20E Kit. RESULTS: According to the statistical analysis, the total amount of the non-commensal bacteria was significantly higher in chronic liver failure (CLF) group than controls (p= 0.001). There was no significant difference between both groups for the presence of other bacteria (p= 0.001) except for Escherichia coli (E. coli). E. coli was isolated from the saliva of 15 cases and only 2 controls. CONCLUSION: Oral cavity may act as a reservoir for enteric bacteria such as E. coli in liver failure patients. Adequate oral and general hygiene might reduce the risk of systemic infection especially in immunocompromised cases.

Helicobacter pylori antibiotic resistance and correlation with cagA motifs and homB gene.

Objectives: Helicobacter pylori (H. pylori) infection caused by antibiotic-resistant strains represents a major public health threat that aggressively promotes gastric cancer progression. Antibiotic resistance evaluation is immensely important to counteract its emergence. Here we merely determine the prevalence of antibiotic resistance in H. pylori isolates and its correlation with cagA motifs and the homB gene. Methods: The antibiotic resistance pattern was investigated on 128 H. pylori isolated strains utilizing the disk diffusion method and study the correlation between it and the presence of pathogenic genes, cagA EPIYA motifs and homB gene, were accurately detected using the PCR. Results: The resistance rates to four antibiotics were 70.1% for metronidazole, 35.5% for amoxicillin, 7.2% for clarithromycin and 8.2% for tetracycline. Resistance phenotypes were separated into two groups, single resistance (63.2%) and multi-resistance (12.5%). The prevalence of cagA-ABCC resistant strains and homB+ resistant strains was significantly higher in cancer (p = 0.04 and p = 0.01, respectively) than those of other diseases. The prevalence of cagA-homB + resistance strains was 21.8% and had a significant correlation with PUD. A significant relationship was observed between amoxicillin resistant rate with ABC-homB (p = 0.0006). Conclusion: The Resistance rate to selected antibiotics in Shiraz is higher than years ago. The presence of cagA-homB + is associated with antibiotic resistance and also homB can be used as a marker to antibiotic resistance status prediction in H. pylori isolated in this area.

Determining spa-type of methicillin-resistant Staphylococcus aureus (MRSA) via high-resolution melting (HRM) analysis, Shiraz, Iran.

OBJECTIVES: Molecular typing methods are useful for rapid detection and control of a disease. Recently, the use of high-resolution melting (HRM) for spa typing of MRSA isolates were reported. This technique is rapid, inexpensive and simple for genotyping and mutation screening in DNA sequence. The aim of this study was to evaluate the ability of HRM-PCR to analysis spa genes amongst MRSA isolates. RESULTS: A total of 50 MRSA isolates were collected from two teaching hospitals in Shiraz, Iran. The isolates were confirmed as MRSA by susceptibility to cefoxitin and detection of mecA gene using PCR. We used HRM analysis and PCR-sequencing method for spa typing of MRSA isolates. In total, 15 different spa types were discriminate by HRM and sequencing method. The melting temperature of the 15 spa types, using HRM genotyping were between 82.16 and 85.66 °C. The rate of GC % content was 39.4-46.3. According to the results, spa typing of 50 clinical isolates via PCR-sequencing and HRM methods were 100% similar. Consequently, HRM method can easily identify and rapidly differentiate alleles of spa genes. This method is faster, less laborious and more suitable for high sample at lower cost and risk of contamination.

Evaluating the Saliva of Burn ICU Patients for Resistant Infections Harbor Metallo-ß-Lactamase Genes.

Pseudomonas aeruginosa and Acinetobacter baumannii are the bacteria which increasingly account for nosocomial infections. Due to high virulence, the rate of Multi-Drug Resistance (MDR) and limited availability of new agents, these infections create significant clinical burdens, making it important to identify the possible sources of their occurrence. The aim of this study was to assess non-lactose fermenting bacteria and their metallo-ß-lactamase (MBLs) genes expression in the Burn Intensive Care Unit (BICU) patients' saliva samples. This cross-sectional study was conducted from 2017 to 2018 on 124 saliva samples of BICU patients. Identified isolates were evaluated for drug susceptibility by disc diffusion method. MBLs production isolates were detected by Modified Hodge test and Imipenem-EDTA Combined disk. MBLs related genes were evaluated by polymerase chain reaction (PCR). A total of 86 Gram negative non-lactose fermenting bacteria (38; A. baumannii) and (48; P. aeruginosa), were detected. All of the A. baumannii isolates were resistant to Carbapenems, while more than 90% of them were sensitive to Colistin. However, the highest sensitivity in P. aeruginosa isolates was related to Carbapenems and Colistin. More than 95% of A. baumannii and 32% of P. aeruginosa were detected MDR. MBLs production was confirmed in 9 (33.33%) P. aeruginosa and 18 (66.67%) A. baumannii isolates. The blaVIM was the most prevalent gene, while this gene was detected in all of MBLs positive strains. This study confirmed the prevalence of carbapenemase producer Gram-negative bacilli in the saliva of BICU patients. The results of the present study provide a new data set about saliva infection source that could lead to the proper antibiotic regimen and better control of drug resistance.

Integron-Related Resistance in New Emerged Staphylococcus lugdunensis Infection in Burn Patients.

Staphylococcus lugdunensis is a coagulase-negative Staphylococcus species that may cause various infections with unusual severity. In spite of the administration of various antibiotics, infections caused by such bacteria are become resistant significantly. Transmission of antibiotic resistance genes, especially by Integron structures, exacerbates the prevalence of resistant strains. To investigate the antibiotic susceptibility pattern of S. lugdunensis as a new emergence in burns, the presence of integron classes (I, II, III) was performed in recent study. Sampling for this study was carried out over a period of 13 months (January 2017 to February 2018) from Amir-Al-Momenin burn center of southwest of Iran, affiliated with Shiraz University of Medical Sciences. Twenty-eight isolates of S. lugdunensis were confirmed by phenotypic tests. The presence of integron classes was evaluated by PCR technique and specific primers. The majority of studied infectious agents were seen in ICU with 28.57%. The prevalence of class I and II integrons was 7 (25.00%) and 2 (7.14%), respectively, in S. lugdunensis isolates, whereas no integron III was found. No significant association was seen between antibiotic resistance and the present integrons (P > .05). Since the prevalence of S. lugdunensis strains as a new emergence infection is increasing in clinical settings especially burns, preventing drug resistance in these isolates is inevitable. So knowing the epidemiology pattern of new emerging infections and their resistant pattern is very helpful in infection control and save hospitalized patients life.

Characterization of SCCmec, spa types and Multi Drug Resistant of methicillin-resistant Staphylococcus aureus isolates among inpatients and outpatients in a referral hospital in Shiraz, Iran.

OBJECTIVES: Molecular typing such as spa typing is used to control and prevent Staphylococcus aureus widespread in hospitals and communities. Hence, the aim of this study was to find the most common types of S. aureus strain circulating in Shiraz via spa and SCCmec typing methods. RESULTS: Total of 159 S. aureus isolates were collected from two tertiary hospitals in Shiraz. Isolates were identified by biochemical tests. Antimicrobial susceptibility tests were performed by standard disk diffusion method and then genetic analysis of bacteria was performed using SCCmec and spa typing. In this study 31.4% of the isolates were methicillin-resistant S. aureus. The majority of isolates were SSCmec type III. Spa type t030 was the most prominent type among MRSA strains. For the first time in Iran, spa003, t386, t1877, t314, t186, t1816, t304, t325, t345 were reported in this study. It was shown that there is a possibility that these spa types are native to this region. Our findings showed that SCCmec II, III and IV disseminate from hospital to community and vice versa. Thus, effective monitoring of MRSA in hospital and community is necessary.

Risk of otitis media with effusion (OME) in children by Pseudomonas aeruginosa.

OBJECTIVE: Two third of children in the world experience otitis media with effusion (OME) at least once in their life. According to the importance of knowing OME reason in pediatrics, beside introduced probable bacterial and viral causal agents, Pseudomonas aeruginosa was evaluated either. METHODS: In this study, 42 middle ear fluid (MEF) samples were collected from pediatrics who confirmed OME by an ears, nose and throat (ENT) specialist. Samples were cultured on bacteriological media for bacterial growth and were either extracted for total DNA and RNA to be tested for introduced bacterial and viral agents with simple and Reverse Transcriptase PCR method within specific primers. RESULTS: Total results from culture and molecular methods showed that the most prevalent infections were Pseudomonas aeruginosa and streptococcus pneumonia with 33.33% and 14.29% respectively. In total, 66.67% of patients were infected with bacteria, 11.9% with test viruses while in 21.42% of patients no infectious agents were detected. Influenza type A was the only virus was detected. CONCLUSION: Pseudomonas aeruginosa was the most prevalent agent while mostly detected in patients who were referred from the tropical and humid region. According to these results, it is highly recommended to know the pattern of OME infection in each area separately for more successful treatment.

Toxin profiles and antimicrobial resistance patterns among toxigenic clinical isolates of Clostridioides (Clostridium) difficile.

OBJECTIVES: Clostridioides (Clostridium) difficile infection as a healthcare-associated infection can cause life-threatening infectious diarrhea in hospitalized patients. The aim of this study was to investigate the toxin profiles and antimicrobial resistance patterns of C. difficile isolates obtained from hospitalized patients in Shiraz, Iran. MATERIALS AND METHODS: This study was performed on 45 toxigenic C. difficile isolates. Determination of toxin profiles was done using polymerase chain reaction method. Antimicrobial susceptibility to vancomycin, metronidazole, clindamycin, tetracycline, moxifloxacin, and chloramphenicol was determined by the agar dilution method. The genes encoding antibiotic resistance were detected by the standard procedures. RESULTS: The most frequent toxin profile was tcdA+, tcdB+, cdtA-, cdtB- (82.2%), and only one isolate harboured all toxin associated genes (tcdA+, tcdB+, cdtA+, cdtB+) (2.2%). The genes encoding CDT (binary toxin) were also found in six (13.3%) isolates. Resistance to tetracycline, clindamycin and moxifloxacin was observed in 66.7%, 60% and 42.2% of the isolates, respectively. None of the strains showed resistance to other antibiotics. The distribution of the ermB gene (the gene encoding resistance to clindamycin) was 57.8% and the tetM and tetW genes (the genes encoding resistance to tetracycline) were found in 62.2% and 13.3% of the isolates, respectively. The substitutions Thr82 to Ile in GyrA and Asp426 to Asn in GyrB were seen in moxifloxacin resistant isolates. CONCLUSION: Our data contributes to the present understanding of virulence and resistance traits amongst the isolates. Infection control strategies should be implemented carefully in order to curb the dissemination of C. difficile strains in hospital.

A multicenter-based study on epidemiology, antibiotic susceptibility and risk factors of toxigenic Clostridium difficile in hospitalized patients in southwestern Iran.

Clostridium difficile (recently Clostridioides difficile) is a leading cause of hospital- and antimicrobial-associated diarrhea (AAD). The present study was carried out to investigate the prevalence of toxigenic C. difficile, antibiotic resistance and its associated risk factors in Iranian hospitalized patients. This cross-sectional study was conducted from October 2017 to June 2018 in three teaching hospitals in southwestern Iran. During this period, a total of 215 non duplicated nosocomial AAD samples were collected from the hospitalized patients older than two years of age. Presumptive C. difficile isolates were identified by standard microbiologic methods and confirmed by specific PCR primers. The minimum inhibitory concentrations (MICs) were determined by the agar dilution method. PCR was carried out to determine the presence of toxin genes (tcdA, and tcdB). In all, from the 215 diarrheal samples, the frequency of C. difficile culture-positive samples was 21.4% (n = 46). Of the 46 C. difficile isolates, 43 carried both toxins, two isolates only had the tcdB gene, and one was negative for both toxins. Overall, all isolates of C. difficile were susceptible to metronidazole and vancomycin. The MIC50/MIC90 of metronidazole and vancomycin were 0.75/2 µg/mL, 0.25/0.75 µg/mL, respectively. The findings of this study show the prevalence of CDI in hospitalized patients in southwestern Iran, highlighting the importance of active surveillance of CDI in hospitals. Meanwhile, all of the tested isolates were susceptible to metronidazole and vancomycin, which encourages the use of these antibiotics as the drug of choice for initial treatment of CDI in our region.

Low Rate of babA2 Genotype among Iranian Helicobacter pylori Clinical Isolates.

INTRODUCTION: The Blood Group Antigen-Binding Adhesion (babA), Outer Inflammatory Protein (oipA) and Sialic Acid-Binding Adhesin (sabA) as outer membrane proteins involved in Helicobacter pylori adherence to gastric mucosa have been suggested to have a role in the pathogenesis. AIM: To investigate the frequency of H. pylori isolates babA2, oipA and sabA genes in Iranian dyspeptic patients. MATERIALS AND METHODS: DNAs were extracted from H. pylori -positive cultures taken from 100 different dyspeptic patients. Genotyping was performed by Polymerase Chain Reaction (PCR), using the specific primers for babA2, oipA and sabA genes. Chi square test was used to investigate association between variables, p<0.05 was considered statistically significant. RESULTS: All (100%) isolates possessed oipA and sabA genotypes, whereas babA2 was detected in 22% of isolates. There was no significant relationship between presence of genes with clinical outcome. The combined genotype oipA +/sabA +/ babA2- was correlated with gastritis. The rate of babA2 genotype in our isolates was lower than other Iranian reports. CONCLUSION: Frequency of babA2 genotype among H. pylori isolates from Southwest of Iran is considerably less than other regions of Iran. Due to heterogeneity of H. pylori strains in different geographic regions, further work will be needed to understand the role of these virulence genes in H. pylori pathogenesis and their possible association with disease outcome.

Isolation and Identification of Nonoral Pathogenic Bacteria in the Oral Cavity of Patients with Removable Dentures.

AIMS AND OBJECTIVES: Dentures in the oral cavity may act as a reservoir of microorganisms, which may be related to systemic infections. The aim of this study was to investigate the nonoral pathogenic bacteria in the oral cavity of patients with removable dentures in Shiraz, Southern Iran. MATERIALS AND METHODS: The bacterial flora of saliva samples from 50 men and 50 women with removable dentures and 100 age- and sex-matched controls with normal dentate were compared using culture, Gram staining, and API20E Kit methods. All data were analyzed using SPSS software. RESULTS: Except for Enterobacter cloacae isolate (P = 0.03), there was no significant difference between both groups for the presence of Escherichia coli, Klebsiella pneumoniae, nonfermenting Gram-negative bacilli, Raoultella ornithinolytica, Raoultella planticola, Kluyvera spp., and Enterobacter aerogenes. No significant correlation was noticed between age and presence of bacteria in the oral cavity. The Gram-negative rod bacteria were more in males, but the difference was not significant. When a total of Gram-negative rods were considered, there was a significant difference between case and control groups (P = 0.004). CONCLUSIONS: Based on our findings that nonoral pathogenic bacteria are detected from the saliva of the denture wearers, general and oral health measures in patients with removable dentures should be adopted to decrease the risk of cross infection.

Comparison of oral Lactobacillus and Streptococcus mutans between diabetic dialysis patients with non-diabetic dialysis patients and healthy people.

INTRODUCTION: Diabetes is associated with higher rates of caries, on the other hand some studies have shown that renal failure can be protective against dental caries. OBJECTIVES: In this study we compared oral Lactobacillus and Streptococcus mutans between diabetic dialysis and non-diabetic dialysis patients and the normal population. PATIENTS AND METHODS: During November 2014 to January 2014, 85 people that referred to our medical care center entered the study. The sample included 30 diabetic dialysis, 28 non-diabetic dialysis patients and 27 healthy people. Oral saliva samples were obtained from their tongue and oral floor for microbiological examination. Patients' data were compared before and after dialysis. RESULTS: The amount of Lactobacillus and S. mutans did not show a significant difference between the three groups (P=0.092 and P=0.966 for S. mutans and lactobacillus, respectively). A positive and meaningful correlation was seen between fasting blood sugar (FBS) levels and the amount of S. mutans in the diabetic dialysis group (P=0.023; r=0.413). A meaningful and positive correlation was also seen between the amount of blood urea nitrogen (BUN) after dialysis and the amount of oral S. mutans in the non-diabetic dialysis group (P=0.03; r=0.403). CONCLUSION: Despite the differences in the prevalence of caries that have been reported between renal failure patients and diabetic patients, we did not find any significant difference between diabetic dialysis, non-diabetic dialysis patients and the healthy population, regarding their amount of oral cariogenic bacteria.

High rate of A2142G point mutation associated with clarithromycin resistance among Iranian Helicobacter pylori clinical isolates.

This study aimed to investigate the clarithromycin resistance and its associated molecular mechanisms among Helicobacter pylori isolates from dyspeptic patients in Shiraz, Iran. From January to May 2014, 100 H. pylori strains were isolated from patients with gastroduodenal disorders. The resistance to clarithromycin was quantitatively evaluated, using Epsilometer (E-test) method. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed on all the isolates to detect A2143G and A2142G mutations in 23S rRNA gene. The H. pylori isolation rate was found to be 31.4%. E-test showed that 20% of isolates were resistant to clarithromycin (MIC ≥ 1 mg/L). MIC of clarithromycin ranged between 0.016 and 24 mg/L. Findings of PCR-RFLP showed that the A2142G was the most (90%) frequently point mutation, followed by the A2143G (10%). No statistically significant difference was found between H. pylori clarithromycin resistance point mutations and patients' gender or age. To the best of our knowledge, this is the first report of high frequency of A2142G point mutation in Iran and probably in other regions of the world. Considering the increasing trend of H. pylori resistance to clarithromycin due to these mutations, it is crucial to investigate the new therapeutic approaches against H. pylori infection.