COVID-19 in patients with anemia and haematological malignancies: risk factors, clinical guidelines, and emerging therapeutic approaches

Extensive research in countries with high sociodemographic indices (SDIs) to date has shown that coronavirus disease 2019 (COVID-19) may be directly associated with more severe outcomes among patients living with haematological disorders and malignancies (HDMs). Because individuals with moderate to severe immunodeficiency are likely to undergo persistent infections, shed virus particles for prolonged periods, and lack an inflammatory or abortive phase, this represents an overall risk of morbidity and mortality from COVID-19. In cases suffering from HDMs, further investigation is needed to achieve a better understanding of triviruses and a group of related variants in patients with anemia and HDMs, as well as their treatment through vaccines, drugs, and other methods. Against this background, the present study aimed to delineate the relationship between HDMs and the novel COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Besides, effective treatment options for HDM cases were further explored to address this epidemic and its variants. Therefore, learning about how COVID-19 manifests in these patients, along with exploiting the most appropriate treatments, may lead to the development of treatment and care strategies by clinicians and researchers to help patients recover faster. Video Abstract.

Association of polymorphism of IL-17A, IL-17F, and IL-6 with Toxoplasma gondii infection susceptibility in HIV/AIDS patients in Shiraz, southern Iran

INTRODUCTION

Toxoplasma gondii infection is considered as one of the most important opportunistic infections and cause of death in HIV patients.

METHODS

In this cross-sectional study, 334 HIV positive patients were included. The molecular test was performed by the restriction fragment length polymorphism-polymerase chain reaction method. Allelic frequency, haplotype analyses, and linkage disequilibrium were calculated. The odds ratio was calculated. The linear regression model was used to analysis of interleukin (IL)-17A, IL-17F, and IL-6 single-nucleotide polymorphism genotypes in HIV patients with and without toxoplasmosis.

RESULTS

In total, 95 tested'patients (28.4%) were positive for toxoplasmosis. The risk of toxoplasma infection in the current study did not correlate with IL-17 and IL-6 polymorphism and the risk of contracting toxoplasma was also not significantly correlated in this study. There was no association between the frequency of alleles and the risk of toxoplasma infection in IL-17 haplotype analysis.

CONCLUSION

The findings of this study revealed that there were significant differences in the serum levels of IL-6 and IL-17A, but not IL-17F, between the case and control groups in various genetic models. However, these polymorphisms did not show a significant relationship with toxoplasma infection in HIV-positive patients. This study represents the first investigation in Iran to explore the role of IL-6 and IL-17 polymorphisms in toxoplasma infection among HIV-positive patients.

The role of periodontitis-associated bacteria in Alzheimer's disease: A narrative review

Alzheimer's disease causes memory loss and dementia in older adults through a neurodegenerative mechanism. Despite the pathophysiological clarification of this cognitive disorder, novel molecular and cellular pathways should be identified to determine its exact mechanism. Alzheimer's disease (AD) is pathologically characterized by senile plaques comprising beta-amyloid and neurofibrillary tangles (NFTs) formed by hyperphosphorylated tau as a microtubule-associated protein with a key role in the pathogenesis of AD. Periodontitis through inflammatory pathways is a risk factor for deteriorating cognitive impairment in AD patients. Poor oral hygiene coupled with immunocompromised status in older adults causes periodontal diseases and chronic inflammations through an oral bacterial imbalance. Toxic bacterial products, including bacteria themselves, can reach the central nervous system through the bloodstream and evoke inflammatory responses. The present review was conducted to investigate relationships between AD and periodontitis-involved bacteria as a risk factor.

Relationship between interleukin 17 polymorphism in rs 2275913 and rs 763780 and interleukin 6 in rs 1800795 gene region with sensitivity to antiretroviral drugs in patients with human immunodeficiency virus

Drug complication is still considered as one of the most important causes of death and drug in-compliance around the world. In this cross sectional study, 372 people living with HIV (PLHIV) above 16 years were enrolled. The drug complication was extracted based on the information of the patient's file. The molecular test was performed by the Restriction Fragment length polymorphism-Polymerase Chain Reaction method. Allelic frequency, haplotype analyses, linkage disequilibrium and odds ratio (OR) were calculated. The linear regression model was used to analyze the association of IL'SNPs with drug complication after adjustment for age and sex. Drug complications were observed in 150(40.3%) participants. The most common drug complications were hematological 94(62.7%) ones. The SNPs- rs 2275913 and rs763780- of IL-17were in complete linkage (D́ = 1 and r = 1). A-A haplotype of IL-17 in SNPs- rs 2275913 and rs763780 can increase the risk of drug complication up to 1.628 times more than other haplotypes and G-G and G-A haplotypes have a protective role among them 0.268 and 0.628 times, respectively. Our result for the first time demonstrated the role of IL-17 polymorphism in induced antiretroviral drug complication incidence. Probably A-A haplotype could increase the immune response to anti-retroviral drugs, and G-G and A-G haplotypes can decrease it.

Detection of genes encoding enterotoxins (SEA-D) in Staphylococcus aureus strains isolated from workers' nasal samples and creamy pastries of Shiraz confectioneries

Background and Objectives

Staphylococcus aureus is responsible for the majority of food poisoning all around the world. Nasal carriers of S. aureus and foodstuffs need for handling are important sources and vehicles to transmit this pathogen to ready-to-eat foods. According to hygienic standards, confectioners should not be contaminated with S. aureus. This study aimed to detect nasal carriers and creamy pastries contaminated with enterotoxigenic S. aureus in confectioneries of Shiraz, Iran.

Materials and Methods

From the confectioneries of Shiraz city, 27 places in the north, south, center, west, and east areas were selected randomly then 100 creamy pastries samples and 117 nasal swabs were collected. Bacteriological and biochemical tests were performed to isolate S. aureus. The polymerase chain reaction (PCR) test was used to identify the virulence and enterotoxins genes of the S. aureus isolates. Agar disk diffusion was performed to find out the antibiotic resistance of the isolates.

Results

Results revealed that 16.24 and 33 percent of workers and creamy pastries were contaminated with S. aureus respectively. Also, 100%, 37%, 58%, and 6% of nasal samples harbored femA, mecA, sea, and sec genes respectively. According to the results 97%, 70%, 54.5%, and 6% of creamy pastries isolates harbored femA, mecA, sea, and sec genes respectively. No isolate carried seb and sed genes. The results also showed that 41.5% of nasals and 5.5% of creamy pastry isolates harbored both sea and sec genes. The sea was the most common enterotoxin gene observed in nasal and creamy pastries. The results of the antimicrobial resistance test showed that 68.42% of nasal and 48.48% of creamy pastry isolates were resistant to cefocxitn (FOX) respectively. Both nasal (89%) and creamy pastry (82%) isolates presented the highest resistance to penicillin (P) and the most sensitivity to trimethoprim-sulphamethoxazole (SXT) (94%). Most of the isolates were sensitive to erythromycin (E), aztreonam (AZM), tetracycline (TE), trimethoprim (TMP), and ciprofloxacin (CP). Isolates of S. aureus harboring multi-enterotoxin genes were resistant to more antibiotics than others.

Conclusion

The presence of enterotoxigenic S. aureus in the workers' nasal samples and creamy pastries of Shiraz confectioneries was high which is a potential public health hazard.

Genotypic evaluation of Pasteurella multocida isolated from cattle and sheep by pulsed-field gel electrophoresis

Pasteurella multocida a Gram-negative bacterium exists as a commensal in the upper respiratory tracts of livestock, and poultry. It is causative agent of a range of diseases in mammals and birds including fowl cholera in poultry, atrophic rhinitis in pigs and bovine hemorrhagic septicemia in cattle and buffalo. This study aimed to isolate P. multocida from sheep and cattle lungs sampled and assessed by bacteriological procedures and pulse field gel electrophoresis (PFGE) characterization. In this study 52 isolated of P. multocida were obtained (2016-2017) from clinically healthy and diseased animals (sheep and cattle) evaluated by PFGE for determining the relationship between them. According to the results of this study 12 sheep isolates had similarities above 94.00% and two cattle isolates showed similarities above 94.00%. When compared between sheep and cattle, most isolates showed a similarity of less than 50.00% indicating the great differences between isolates. It is noteworthy that in the present study, performed by PFGE to determine the type of P. multocida isolates, a very high distinction was made to determine the type of isolates and the relationship between isolates based on fragments in their genome using enzymes.

Disinfection of dentinal tubules with diclofenac sodium and N-Acetylcysteine compared with calcium hydroxide as intracanal medicaments against Enterococcus faecalis

The purpose of this study was to evaluate the disinfection of dentinal tubules with diclofenac sodium (DS), N-acetylcysteine (NAC) and calcium hydroxide (CH). Contaminated dentinal blocks were divided into two control and seven experimental groups (n = 15): CH, DS, NAC, CH + 5% DS, 50% CH + 50% DS, CH + 5% NAC and 50% CH + 50% NAC. After seven days, dentine debris was obtained from two depths of 100 and 200 µm. The bacterial load was assessed by counting the number of colony-forming units (CFUs). Pure DS exhibited maximum antibacterial activity at both depths. At 200 µm, it showed statistically significant differences with all the other groups (P < 0.05). Mixing CH with either 5% or 50% of DS and NAC did not increase the antibacterial efficacy (P > 0.05). Pure DS was most effective in disinfecting dentinal tubules, and mixing CH with DS or NAC is not recommended.

Virulence factors, serogroups, and antibiotic resistance of Shiga-toxin producing Escherichia coli from raw beef, chicken meat, and vegetables in Southwest Iran

Background

Shiga-toxin-producing Escherichia coli (STEC) is an important food-borne pathogen causing human diseases with severe symptoms. Although the O157 serotype has been mostly isolated from human specimens, the increasing incidence rates of non-O157 serogroups have attracted special attention in recent years.

Aims

Evaluation of the epidemiology and identification of different characteristics of STEC isolates from raw beef, chicken meat, and vegetable samples in Shiraz, Southwest Iran.

Methods

Two hundred beef and chicken meat samples from different parts of carcasses and four hundred vegetable samples (carrots, lettuce, cucumber, and leafy greens) were randomly taken; STEC were isolated and confirmed using standard microbiological methods. Antimicrobial susceptibility testing (AST) was performed using the Kirby-Bauer disc diffusion method. Polymerase chain reaction (PCR) was used for the identification of O-serogroups, virulence, and antibiotic resistance genes.

Results

52% of beef, 8% of chicken, and 7.2% of vegetable samples were STEC-positive. Further, the highest frequency of virulence factors belonged to the co-existence of stx1 and stx2. O157 serogroup was only detected in beef (3.8%) and lettuce (16.6%) isolates, while the rates of the non-O157 serogroups were relatively high (up to 44.2%). The highest resistance rate in the STEC isolates of different samples belonged to nalidixic acid (62.5%), tetracycline (55.7%), and ampicillin (48%).

Conclusion

Paying more attention to non-O157 serogroups in future studies is recommended due to the relatively high prevalence of theses STEC serogroups in our study. Besides, the high level of resistance to some antibiotics observed in this study needs to be addressed.

The effect of photodynamic therapy by gold nanoparticles on Streptococcus mutans and biofilm formation: an in vitro study

In this experimental study, we aimed to evaluate the antibacterial and anti-biofilm effects of photodynamic therapy with a photosensitizer in conjunction with Gold nanoparticles against Streptococcus mutans as an important cariogenic bacterial agent. This experimental in vitro study evaluated the antibacterial and anti-biofilm effect of five groups as followed against S. mutans: methylene blue (MB), Gold nanoparticles (AuNPs), methylene blue conjugated with Gold nanoparticles (MB-AuNPs), MB mediated photodynamic therapy (MB mediated PDT) and methylene blue conjugated with Gold nanoparticles mediated photodynamic therapy (MB-AuNPs mediated PDT). InGaAlP laser (Azor-2 K) with 25 mW total output, 660 nm wavelength and laser probe cross-section of 0.78 cm² was used for methylene blue activation. Total dose of 19.23 J/cm² for 10 min was irradiated to each group. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and colony forming unit (CFU) were determined. Bacterial biofilm formation inhibition was assessed by crystal violet staining (The microtiter plate biofilm assay). The viability of S. mutans cells was assessed by MTT assay. MB mediated PDT and MB-AuNP mediated PDT were the most effective method for S. mutans biofilm inhibition (P < 0.05). MB alone, MB-AuNP alone and MB mediated PDT and MB-AuNP mediated PDT had the same effect against the planktonic phase of S. mutans (P > 0.05). Also they had similar pattern for bacterial growth inhibition and bactericidal effect (P > 0.05). Gold nano particle mediated photodynamic therapy represented antibacterial and antibiofilm activity against S. mutans; but this modality was not more effective than routine PDT.

Relative frequency of hepatitis B virus, human papilloma virus, Epstein-Barr virus, and herpes simplex viruses in the semen of fertile and infertile men in Shiraz, Iran: A cross-sectional study

Background

About 8-12% of couples on reproductive age suffers from infertility worldwide. Since 1993, the role of genital tract infections by microbes, including viruses that can infect the sperm, in human infertility has been proposed.

Objective

To investigate the frequency of hepatitis B virus (HBV), human papilloma virus (HPV), Epstein-Barr virus (EBV), and herpes simplex virus (HSV) infection in the semen of fertile and infertile men referred to the Mother and Child Hospital, Shiraz, Iran.

Materials and Methods

In this cross-sectional study, 350 men including 200 infertile and 150 fertile men were included. All semen samples were allowed to liquefy, followed by the assessment of sperm parameters. DNA was extracted using a DNA extraction kit (CinaGene, Tehran, Iran) according to the manufacturer's instructions. Detection of HBV, HPV, EBV, and HSV1/2 was done by the PCR method.

Results

The mean age of the participants was 36 ± 7 yr. Molecular results showed that 16 samples (8%) of infertile men and 5 (3.3%) of fertile men were positive for HBV, which was not statistically significant (p = 0.069). Only one sample of the fertile participants was positive for HPV. None of the semen samples of the infertile or fertile groups was positive for the presence of EBV or HSV1/2.

Conclusion

The results of this study indicated that HBV, HPV, EBV, and HSV might not be involved in men's infertility. Further studies are recommended for clarifying the role of these viruses in infertility.

The effects of hepatitis B virus infection on natural and IVF pregnancy: A meta-analysis study

BACKGROUND

Hepatitis B virus (HBV) has been considered a significant cause of human reproductive failure in different studies; however, there is a considerable disagreement on the true impacts of HBV on female reproduction. This study has evaluated the impact of HBV infection on pregnancy complications in natural pregnancy and also on pregnancy outcomes in women undergoing in vitro fertilization (IVF) treatment.

METHOD

We searched Embase, Web of Science, PubMed and Google Scholar databases to identify the potentially relevant studies. Summary odds ratio (OR) or standardized mean difference (SMD) with 95% confidence interval (CI) was applied to assess the relationship. Heterogeneity testing, sensitivity analysis and publication bias testing were also performed.

RESULTS

A total of 42 studies concerning the effect of HBV infection on the natural and IVF pregnancy were included in this study. Our meta-analysis results revealed that HBV infection had a positive correlation to gestational diabetes mellitus (GDM) [OR = 1.32 (1.17-1.48) (p < 0.01)] and preterm birth [OR = 1.26 (1.14-1.40) (p < 0.01)] in natural pregnancy; however, HBV infection was not significantly associated with decreased fertility rates among the patients who underwent IVF.

CONCLUSION

This study revealed a strong association of GDM and preterm birth with higher rates of HBV infection in pregnant women. Also, our results suggested that HBV infection in patients undergoing IVF may not negatively influence the pregnancy outcome. It may be rational to conclude that IVF might be rather a safe and effective method for HBV+ females who desire to have children.

SARS-CoV-2 effects on male reproduction: should men be worried??

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has placed a global challenge on both healthcare and society. So far, studies have shown that men are more prone to become ill than women and are more likely to die compared to female patients. Higher rates of positive cases and fatality in men than women have drawn the attention of scientists to investigate the possible impacts of SARS-CoV-2 on the male reproductive system. In this review, we tried to summarise so far findings on the effect of the SARS-CoV-2 on the male reproductive function to further assess the potential risks of this novel coronavirus on male reproductive health.

The effect of endocervical and catheter bacterial colonisation during in vitro fertilisation and embryo transfer (IVF-ET) on IVF success rate among asymptomatic women: a longitudinal prospective study

The adverse effects of bacterial contamination during in vitro fertilisation and embryo transfer (IVF-ET) have been studied previously. However, data on asymptomatic women with positive bacterial culture and their IVF outcome are lacking. This prospective longitudinal study was conducted on 74 women undergoing IVF-ET, of whom specimens from the endocervix and ET catheter were taken and sent to a laboratory for microbiological assessment. Then, patients were followed up for evaluation of chemical pregnancy (β-HCG > 25 mIU/mL) and clinical pregnancy (detected foetal heartbeat). The findings revealed that there was no significant difference in terms of biochemical (35.4% vs. 19.2%, p= .116) and clinical pregnancy rate (25.0% vs. 15.4%, p= .257) among ET catheter culture positive and negative women. This finding allows us to conclude that the positive culture in the absence of clinical signs of infection may not increase the risk of implantation failure.Impact StatementWhat is already known on this subject? There is growing evidence indicating that endometritis may decrease the endometrial receptiveness in in vitro fertilisation (IVF) cycles; however, there is a paucity of knowledge regarding IVF outcomes when the bacterial culture of embryo transfer (ET) catheter is positive.What the results of this study add? The present study demonstrates that positive ET catheter culture in asymptomatic women does not increase the risk of IVF failure.What the implications are of these findings for clinical practice and/or further research? Positive-culture, per se, may not be associated with poor IVF outcomes and further studies should be undertaken on this topic in various clinical settings using different protocols.

Clonal Relatedness, Phylotyping and Antimicrobial Susceptibility of Extended- spectrum-beta-lactamase Producing Uropathogenic Escherichia coli Isolates from Outpatients and Inpatients

OBJECTIVES

Antibiotic resistance, phylogenetic groups and Pulsed-Field Gel Electrophoresis (PFGE) patterns were evaluated in urinary tract infection (UTI) Escherichia coli (E. coli) isolates from outpatients and inpatients.

METHODS

In this study, antibiotic resistance to E. coli isolated from non-hospitalized and hospitalized patients (153 outpatients and 147 inpatients ) was evaluated in Shiraz County, Iran. Phylogenetic groups and Pulse Field Gel Electrophoresis (PFGE) patterns of 143 ESBLs-producing E. coli were also assessed.

RESULTS

The prevalence of ESBL-producing E. coli was shown to be 46.4% and 49% in the outpatient and inpatient UTI E. coli isolates, respectively. Most ESBL-producers were detected on patients hospitalized in clinical surgery units (66.7%) and intensive care units (62.5%). Phylogenetic group D was the dominant group in both the outpatient and inpatient isolates (67.6% and 61.1%, respectively) and also in internal, clinical surgery and ICU units. PFGE results showed more relatedness (>80% similarity) among inpatient isolates. PFGE analysis of 49 ESBL-producing inpatient E.coli in hospital units revealed 17 different pulsotypes, consisting of 11 clones and 6 single patterns. There were no clonal patterns in outpatient isolates, and similarity among the outpatient isolates and also between inpatient and outpatient isolates was less than 80% (75% and 66%, respectively).

CONCLUSION

The results showed extreme genomic diversity among the ESBL-producing E. coli isolates in terms of the community and multiclonal dissemination of ESBL-producing E. coli isolated from hospital units.

Surface roughness, plaque accumulation, and cytotoxicity of provisional restorative materials fabricated by different methods

Fabricating method may affect the surface properties and biological characteristics of provisional restorations. This study aimed to evaluate the surface roughness, plaque accumulation, and cytotoxicity of provisional restorative materials fabricated by the conventional, digital subtractive and additive methods. Sixty-six bar-shaped specimens (2×4×10 mm) were fabricated by using provisional restorative materials through the conventional, digital subtractive and additive methods (n = 22 per group). Ten specimens of each group were used for surface roughness and plaque accumulation tests, 10 specimens for cytotoxicity assay, and 2 specimens of each group were used for qualitative assessment by scanning electron microscopy. The Ra (roughness average) and Rz (roughness height) values (μm) were measured via profilometer, and visual inspection was performed through scanning electron microscopy. Plaque accumulation of Streptococcus mutans and cytotoxicity on human gingival fibroblast-like cells were evaluated. The data were analyzed with one-way ANOVA and Tukey's post hoc test (α = 0.05). Surface roughness, biofilm accumulation and cytotoxicity were significantly different among the groups (P<0.05). Surface roughness was significantly higher in the conventional group (P<0.05); however, the two other groups were not significantly different (P>0.05). Significantly higher bacterial attachment was observed in the additive group than the subtractive (P<0.001) and conventional group (P = 0.025); while, the conventional and subtractive groups were statistically similar (P = 0.111). Regarding the cytotoxicity, the additive group had significantly higher cell viability than the subtractive group (P = 0.006); yet, the conventional group was not significantly different from the additive (P = 0.354) and subtractive group (P = 0.101). Surface roughness was the highest in conventionally cured group; but, the additive group had the most plaque accumulation and lowest cytotoxicity.

The Prevalence of Bacteriospermia in Infertile Men and Association with Semen Quality in Southwestern Iran

INTRODUCTION

Infertility considered as a social and public health issue and estimated that most of these infertile couples are residents of developing countries. Infectious diseases including the history of Sexually Transmitted Infections (STIs) may impact on male reproductive function. Therefore, the present study aimed to investigate the prevalence of bacterial contaminants of semen and probable association with sperm quality of infertile men in Iranian population.

METHODS

The study population consisted of 200 infertile men and 150 fertile men attending an infertility Center in southwestern Iran during the study period in 2015. The assessment of sperm parameters was according to the World Health Organization (WHO) guidelines. The presumptive pathogens were identified using standard microbiology tests and confirmed by specific PCR primers.

RESULTS

The prevalence of bacteriospermia in the semen of the infertile group was significantly higher than that in the fertile group (48% vs. 26.7%, P <0.001). The microbiological analysis of samples showed that the most abundant species of bacteria in semen of infertile men were Chlamydia trachomatis (12.5%) followed by Neisseria gonorrhoeae (11%). On the other hand, in the control group, Lactobacillus spp. (17.3%) was the most isolated pathogen. Results showed that the presence of N. gonorrhoeae, C. trachomatis, Mycoplasma genitalium, Haemophilus, and Klebsiella was significantly associated with sperm abnormality.

CONCLUSIONS

Based on our findings, it seems that bacteriospermia is associated with alterations in the properties of semen which may lead to a decrease in the fertilization potential of sperm. Therefore, immediate and appropriate treatment is necessary before investigating every other possible cause of infertility.

Characterization and antibiotic resistance pattern of diffusely adherent Escherichia coli (DAEC), isolated from paediatric diarrhoea in Shiraz, southern Iran

Diarrhoea is a major health concern, especially in developing countries. Research has implicated diffusely adherent Escherichia coli (DAEC) strains as a cause of diarrhoea. In this study, we investigated the prevalence, adherence assay, virulence gene profiles and antimicrobial resistance of DAEC at a hospital in southern Iran. In this cross-sectional study, 309 infants and children under the age of 13 years with diarrhoea who had been referred to Shahid Dastgheib Hospital, Shiraz between October 2018 and May 2019 were recruited. Microbiological methods, PCR, HEp-2 adherence assay and antimicrobial susceptibility test were used. Of the 309 stool samples, 207 (66.9%) were found to contain E. coli by biochemical tests and culture. Molecular analysis of Afa/Dr and AIDA-I adhesin-encoding genes showed that 14 (6.7%) out of 207 E. coli isolates were DAEC. All DAEC isolates in HEp-2 cells showed a diffusely adherent pattern. The virulence genes sat, pet, sigA, pic, astA and fimH were found in 50%, 0%, 14.2%, 14.2%, 21.4% and 100% of DAEC isolates, respectively. The most effective antibiotic against the DAEC isolates was imipenem (92.8%) and the least effective was ampicillin (0%). Our findings expand the knowledge on DAEC prevalence and its characteristics in Iran. It also explains the role of virulence genes in DAEC pathogenesis. The results showed that although the prevalence of DAEC is low, these strains exhibit a high rate of antimicrobial resistance as well as high frequency for carrying virulence genes.

Photodynamic antimicrobial chemotherapy using indocyanine green in experimentally induced intraoral ulcers in rats

BACKGROUND

Photodynamic antimicrobial chemotherapy (PACT) is a promising modality for eradication of microorganisms from the wound. This study aimed to investigate the effectiveness of PACT using indocyanine green (ICG) for reduction of bacterial load of oral ulcers in rats and its impact on the healing process.

METHODS

In this experimental study, 50 adult male Sprague Dawley rats were recruited. Oral ulcers were surgically made on the left cheek mucosa, and animals were randomly assigned into five groups (n = 10). Wound site in groups 1, 2, and 3 was irrigated with the sterile saline (0.9%), chlorhexidine (CHX; 0.2%), and ICG solutions (1 mg/mL), respectively. Group 4 was exposed to laser irradiation using 810 nm diode laser on continuous-wave mode for 30 seconds (fluence: 55 J/cm² , power: 300 mW, spot size: 4.5 mm). In group 5, PACT was performed using topical application of ICG followed by laser irradiation in the same way as the previous group. Bacterial load of oral ulcers was assessed before and after each treatment modality. Besides, rats were sacrificed on the 5th day post ulceration and histological features of healing were evaluated.

RESULTS

Bacterial load was significantly reduced merely in the PACT-ICG-treated group by one log (P < .0001). Animals in the PACT-ICG-treated group also showed an accelerated healing in comparison with others on the 5th day of an experiment.

CONCLUSION

Photodynamic antimicrobial chemotherapy using topical application of ICG has a potential to reduce the bacterial load of oral ulcers and accelerate wound repair. Therefore, it can be considered as an alternative to currently available modalities for wound management.

The effects of human immunodeficiency virus, human papillomavirus, herpes simplex virus-1 and -2, human herpesvirus-6 and -8, cytomegalovirus, and hepatitis B and C virus on female fertility and pregnancy

Female infertility may be defined as a woman of reproductive age being unable to become pregnant after a year of regular unprotected sexual intercourse. Social, genetic, endocrine, physiological, and psychological factors as well as lifestyle habits (i.e., smoking and alcohol consumption), either alone or in combination with male factors, are major causes. However, approximately 15-30% of cases of female infertility remain unexplained. Numerous investigations have also indicated that microbiomes play an important role in human reproduction. All parts of the female reproductive system may be influenced by infectious and pathological agents, especially viruses, and these may interfere with reproductive function and so are risk factors for infertility, although in many cases an exact role is unclear. We present an overview of the impact of common viral infections on female reproduction, searching Medline, PubMed, Scopus, and Google scholar databases for potentially relevant studies of viruses known to have a potential effect. Human immunodeficiency virus (HIV), herpes simplex virus (HSV) and human herpesvirus (HHV) increase infertility rates whilst human papillomavirus (HPV), cytomegalovirus (CMV), and hepatitis B and C virus (HBV, HCV) infections mostly lead to higher abortion and miscarriage rates. Moreover, HPV infection is linked to increased tubal infertility, endometriosis, and pelvic inflammatory disease. HPV was the most frequently observed infection and with lower pregnancy rate and foetal death in women undergoing IVF treatments. Assisted reproductive treatment could be a safe and effective approach for HIV and HBV infected women.

The first report of Enterobacter gergoviae carrying bla NDM-1 in Iran

OBJECTIVES

Prompt detection of extended-spectrum β-lactamases (ESBL) and carbapenemase-producing enterobacteriaceae is crucial for infection prevention and control strategies. The present study aimed to characterize the ESBL and carbapenemase genes among Enterobacter isolates from an Iranian inpatient population.

MATERIALS AND METHODS

A total of 96 Enterobacter isolates obtained from inpatients between June 2016 and March 2017, were identified by the conventional microbiological methods and diagnostic kits. Antimicrobial susceptibility pattern was performed using the disk diffusion method. The ESBL and carbapenemase genes were screened using polymerase chain reaction (PCR).

RESULTS

All clinical isolates of Enterobacter were classified as E. gergoviae (52, 54.2%), E. aerogenes (34, 35.4%), E. cloacae (7, 7.3%), Cronobacter (E). sakazakii (3, 3.1%). The highest and lowest antimicrobial resistance rates were observed against ampicillin (93.8%) and imipenem (21.9%). High prevalence of multi-drug resistance (MDR=96.9%) was substantial. Of the 96 Enterobacter isolates, 35 (36.5%) and 28 (29.2%) were phenotypically ESBL-positive and non-susceptible carbapenem, respectively. Overall, the frequency of evaluated genes was as follows: blaCTX-M =25 (26%), blaTEM =30 (31.3%), blaSHV =12 (12.5%), blaIMP =3 (3.1%), blaVIM =0 (0%), blaNDM =8 (8.3%), and blaKPC =0 (0%).

CONCLUSION

In this study, we report for the first time the presence of E. gergoviae harboring blaNDM from an Iranian population. Regarding the increase of MDR Enterobacter spp. in our region, strict hygiene rules will be needed to control the quick spread of ESBL and carbapenemase-producing Enterobacter isolates in healthcare facilities of developing countries.

Bacterial infection of the male reproductive system causing infertility

Bacterial infections play a disruptive and hidden role in male reproductive failure. Different kinds of bacteria are often able to interfere with reproductive function in both sexes and lead to infertility. In this study, to further evaluate the role of bacterial infections in male reproduction we provided an extensive overview of so far researches investigating the effects of bacterial infections on male fertility. We searched Medline, PubMed, Scopus and Google scholar databases to identify the potentially relevant studies on bacterial infections and their implications in male infertility. All the bacteria included in this article have negative effects on the male reproductive function; however, there is ample evidence to blame bacteria such as Escherichia coli, Chlamydia trachomatis, Ureaplasma, Mycoplasma and Staphylococcus aureus for reduced fertility and deterioration of sperm parameters. More studies are needed to clarify the molecular mechanisms by which different bacteria exert their detrimental effects on male reproductive system. Getting more insight into probable mechanisms, would significantly facilitate the production of new, advanced, and effective remedies in the future. In view of all evidence, we strongly suggest increasing awareness among people and considering screening programs for patients seeking fertility both to avoid transmission and to improve fertility outcomes among them.

Evaluation of the Preventive Effect of Composites Containing Silver and TiO2 Nanoparticles on Demineralization around Orthodontic Brackets

AIM

The aim of this study was to investigate the antidemineralization effect of composites containing silver and titanium dioxide (TiO₂) nanoparticles used for bonding brackets to tooth specimens.

MATERIALS AND METHODS

A total of 75 freshly extracted teeth were etched and primed and then randomly assigned to three adhesive groups: (1) conventional orthodontic adhesive, (2) conventional adhesive mixed with TiO₂ nanoparticles, and (3) conventional adhesive mixed with silver nanoparticles. In each group, brackets were bonded with the pertinent adhesive. Teeth were painted with varnish on all surfaces except a 2-mm rim around brackets. Specimens were subjected to a cariogenic process in a circulating microbial model inoculated with Streptococcus mutans and Lactobacillus casei for 12 days and subsequently sectioned for cross-sectional microhardness testing. In each specimen, enamel microhardness was determined in three locations: 25-30 μm and 1.5 mm away from the bracket and under the varnish-protected enamel. Hardness of enamel in the first two locations was reported as a percentage of the protected enamel hardness.

RESULTS

Enamel hardness was higher at 25-30 μm away from brackets in both the experimental groups (p value < 0.05), and the nanoparticles acted similarly in this location (p value = 0.992). At 1.5 mm away from the brackets, there was no difference between experimental and control groups (p value > 0.05); the effect of TiO₂ attenuated in this location while silver remained as potent.

CONCLUSION

Both nanoparticles resulted in decreased demineralization at 25-30 μm from the bracket but farther away the effect of TiO₂ was diminished.

CLINICAL SIGNIFICANCE

According to the results of this study, composites containing silver and TiO₂ nanoparticles can be suggested as anti-demineralization adhesives in case their biocompatibility is proved.

Dissemination Pattern of Multidrug Resistant Carbapenemase Producing Klebsiella pneumoniae Isolates Using Pulsed-Field Gel Electrophoresis in Southwestern Iran

Background

Klebsiella pneumoniae is an important cause of healthcare-associated infection. Carbapenemases have increasingly been reported in Enterobacteriaceae, especially in K. pneumoniae.

Propose

The objective of this study was to determine antibiotic resistance patterns, and the molecular epidemiology of multidrug resistant K. pneumoniae isolates, obtained from hospitalized patients in Shiraz, Iran.

Methods

In this study, 60 K. pneumoniaeisolates were collected from Nemazee and Faghihi referral hospitals. Antibiotic susceptibility testing and MIC were performed by disk diffusion test and Epsilometer (E)-test strips, respectively. Carbapenemase genes were identified by polymerase chain reaction and sequencing. Then, clonal relationships were analyzed, using PFGE.

Results

Thirty-three out of 60 K. pneumoniae isolates were resistant to carbapenems. Among the isolates, 86.6% were multidrug resistant (MDR). Polymyxin B (18.3%) and tigecycline (23.3%) were shown to be the most active agents against K. pneumoniae isolates. In our study, the high prevalence of bla_NDM (45%) and bla_OXA-48 (10%) was detected.

Conclusion

The results of this study revealed the widespread carbapenemase gene between different wards in hospitals as a risk factor for treatment options. PFGE analysis showed 11 clusters and 3 singletons based on an 80% similarity level. Also, PFGE analysis showed that there were similar genetic patterns among K. pneumoniae isolates and these patterns were responsible for the distribution of infection in hospitals.

In vitro Reducing Effect of Cloxacillin on Minimum Inhibitory Concentrations to Imipenem, Meropenem, Ceftazidime, and Cefepime in Carbapenem-resistant Pseudomonas aeruginosa Isolates

Today, resistance to antibacterial agents is the most important problem facing public health. Pseudomonas aeruginosa is a common gram-negative bacterium and an important cause of nosocomial infections. Resistance to many antibiotics in strains of P. aeruginosa isolated from hospital settings such as cephalosporins and carbapenems have been recently reported. Therefore, the introduction of a new strategy to treat the infection of these organisms will be beneficial. In this study we determined the ability of cloxacillin to reduce Minimum Inhibitory Concentrations (MICs) of carbapenem-resistant P. aeruginosa to imipenem (IMI), meropenem (MEM), ceftazidime (CAZ), and cefepime (FEP). From 2015 to 2017, 61 non-duplicates of carbapenem-resistant P. aeruginosa were collected from clinical samples of hospitalized patients in Kerman, Iran. The MICs of the isolates to IMI, MEM, CAZ, and FEP with/without cloxacillin were determined by microbroth dilution method. The level of MIC of isolates to carbapenems (IMI and MEM) and cephalosporins (CAZ and FEP) ranged from 1-256 μg/mL and 4-1024 μg/mL alone and from 1-32 μg/mL and 1-512 μg/mL in combination with cloxacillin, respectively. The MIC showed a significant difference reduction after the addition of cloxacillin (P ≤ 0.05). Our results showed in vitro potentially of cloxacillin in reduction of MIC to IMI, MEM, CAZ, and FEP in multi-drug resistant P. aeruginosa, therefore combination of these antibiotics with cloxacillin could be beneficial for treatment of infections caused by multi-drug resistant P. aeruginosa.

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.

High prevalence of vancomycin and high-level gentamicin resistance in Enterococcus faecalis isolates

Multiple drug-resistant enterococci are major cause of healthcare-associated infections due to their antibiotic resistance traits. Among them, Enterococcus faecalis is an important opportunistic pathogen causing various hospital-acquired infections. A total of 53 E. faecalis isolates were obtained from various infections. They were identified by phenotypic and genotypic methods. Determination of antimicrobial resistance patterns was done according to CLSI guidelines. The isolates that were non-susceptible to at least one agent in ≥3 antimicrobial categories were defined as multidrug-resistant (MDR). Detection of antimicrobial resistance genes was performed using standard procedures. According to MDR definition, all of the isolates were MDR (100%). High-level gentamicin resistance was observed among 50.9% of them (MIC ≥ 500 μg/ml). The distributions of aac(6')-Ie-aph(2'')-Ia and aph(3')-IIIa genes were 47.2% and 69.8%, respectively. The aph(2'')-Ib, aph(2'')-Ic, aph(2'')-Id, and ant(4')-Ia genes were not detected. Vancomycin resistance was found in 45.3% of strains. The vanA gene was detected in 37.7% of isolates, whereas vanB and vanC₁ genes were not observed in any strain. Erythromycin resistance rate was 79.2% and the frequencies of ermB and ermC genes were 88.6% and 69.8%, respectively. The ermA and msrA genes were not present in any of the isolates. Our data indicate a high rate of MDR E. faecalis strains. All of high-level gentamicin-resistant isolates carried at least one of aac(6')-Ie-aph(2'')-Ia or aph(3')-IIIa genes. Distribution of vanA was notable among the isolates. In addition, ermB and ermC were accountable for resistance to erythromycin.

Gonorrhea and syphilis co-infection and related risk factors in HIV patients from Shiraz, South of Iran

Background:

Neisseria gonorrhea and Treponema pallidum as an obligate human pathogen are two common causes of sexually transmitted diseases (STDs). The present study aimed to determine the prevalence of N. gonorrhoeae and T. pallidum among human immunodeficiency virus (HIV) patients in the southwest Iran.

Methods:

This retrospective study was performed from 2004 to 2013, on HIV patients who were tested for detection of gonorrhea and syphilis infection at Shiraz HIV/AIDS Research Center. ELISA technique was used for preliminary detection of HIV and confirmed by a Western Blotting test. Gonorrhea was routinely diagnosed using direct Gram-staining and culturing on selective agar. Syphilis was routinely diagnosed by RPR test.

Results:

Of the 806 HIV patients, 39 (2.6%) cases had co-infection with gonorrhea. Compared with mono-HIV infected patients, gonorrhea was significantly more likely among the males (69.4% vs. 92.3%, P=0.002). History of addiction and prison seems to be a significant risk factor for gonorrhea infection (P<0.05). Also, the mean of CD4+lymphocyte was higher among gonorrhea infected patients (368±238 vs. 415±328). Logistic regression analysis showed that sexual contact increased risk of gonococcal infection about 4 fold (OR: 4, CI: 1.7-9.39, P=0.001). None of the HIV patients had syphilis co-infection.

Conclusions:

As a preliminary survey, our findings provided unique information on the prevalence of gonorrhea and syphilis co-infections among HIV patients. Moreover, we introduced the main risk factors associated with gonorrhea co-infection in HIV patients in our region including gender, history of addiction and prison, CD4+lymphocyte count, and transmission routes for effective management of STDs.

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.

Genetic relatedness of the Escherichia coli fecal population and strains causing urinary tract infection in the same host

It is common knowledge that fecal microbiota is a primary source of Escherichia coli causing urinary tract infections (UTIs) via the fecal-perineal-urethral route. But, it is still unknown whether E. coli UTI is mainly caused by dominant fecal E. coli isolates (prevalence hypothesis) or the isolates that possess more virulence factors (special pathogenicity hypothesis). In the present study, the urine E. coli isolates of 30 women with UTI were compared with the fecal E. coli isolates of the same patients and healthy control individuals according to the phylogenetic group, virulence genotype, and antibiotic susceptibility pattern. The genetic relatedness of the isolates was specified and compared by pulsed-field gel electrophoresis (PFGE). PFGE analysis showed that most patients (73.3%) had distinct urine isolates which were not similar to any of their fecal isolates. Based on the phylogenetic analysis, most of the urine and fecal isolates of healthy women were assigned to phylogenetic group B2, followed by D. The distribution of phylogenetic groups was significantly different between the urine and the fecal isolates of patients (p < 0.05). The prevalence of fimH and ompT among urine isolates was significantly more than that among fecal isolates. The level of multidrug resistance was higher among urine isolates. Although more in-depth researches are required, the present study could be supported by pathogenicity hypothesis. Furthermore, concerning the antibiotic resistance pattern among uropathogenic E. coli should be highly considered.

Promising Antibacterial Effect of Copper Oxide Nanoparticles against Several Multidrug Resistant Uropathogens

Background: Recently, nanotechnology has been demonstrated to be a promising application to overcome the problem of antibiotic resistance. In the present study, we aimed to determine the antibacterial activity of copper oxide nanoparticles (CuO NPs) on several multiple-drug resistant (MDR) uropathogenic strains. Methods: This in vitro case-control study was performed on 4 uropathogenic bacteria including Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa. The antibacterial property was evaluated by well diffusion method at different concentrations of CuO NPs. Results: Overall, NPs concentration of 10, 25 and 50 µg/mL showed the remarkable antibacterial activity. A lower effect was seen against S. aureus strains. CuO NPs exhibited maximum bacterial growth inhibition against E. faecalis strains. In most of the cases, the zone of inhibition in 50 µg/mL concentration was closest to control positive antibiotics. Conclusion: In summary, CuO NPs as an alternative to conventional antibiotics that are currently used showed dose-dependent on antibacterial activity against different uropathogens, specificity towards pathogenic Gram-positive bacteria. This promising antibacterial activity of CuO NPs suggesting the development of NPs coatings on the different surface of biomedical materials for applications in different antimicrobial control systems.

Experimental Evaluation of the Effect of Zinc Salt on Inhibition of Streptococcus mutans

STATEMENT OF THE PROBLEM

The rate of antibiotic resistance in bacteria and side effects of antibiotics and oral and teeth health care products are increasing. Therefore, researchers aim at finding new alternatives to control bacteria of dental caries.

PURPOSE

The objective of this study was to investigate the inhibitory and bactericidal effects of different concentrations of zinc sulfate and zinc acetate solutions on the main recognized agent of dental caries, Streptococcus mutans.

MATERIALS AND METHOD

In this experimental study, different concentrations of aqueous zinc sulfate and zinc acetate solutions were prepared and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these salts for Streptococcus mutans were determined in compare with penicillin, chlorhexidine by micro-serial dilution method. In addition, the diameters of zone of inhibition for these salt solutions in four concentrations along with chlorhexidine, as the control, were detected by the disc diffusion method.

RESULTS

MIC and MBC of zinc sulfate solution were higher than penicillin and chlorhexidine. There were not statistically significant differences between the MIC and MBC of zinc acetate solution, penicillin, and chlorhexidine. In 25 and 50 µg/mL concentrations, the diameters of inhibition zone for zinc sulfate were more than zinc ac.

CONCLUSION

Zinc sulfate and zinc acetate salts with 37.19 and 31.25 µgr/mL concentration had inhibitory effect on Streptococcus mutans growth respectively, although, no priority in antibacterial activity of the studied zinc salts was determined in comparison with penicillin and chlorhexidine.

Antibiotic resistance pattern and molecular characterization of extended-spectrum β-lactamase producing enteroaggregative isolates in children from southwest Iran

Introduction

Enteroaggregative Escherichia coli (EAEC) has been implicated as an emerging cause of traveler’s diarrhea, persistent diarrhea among children, and immunocompromised patients. The present study aimed to investigate the prevalence of antibiotic resistance, extendedspectrum β-lactamase (ESBL) production, and virulence factors of EAEC isolates obtained from Iranian children suffered from diarrhea.

Materials and methods

In this cross-sectional study, from March 2015 to February 2016, 32 EAEC isolates were collected from fecal samples of children aged <12 years with diarrhea in southwest of Iran. All EAEC isolates identified using phenotypic and molecular methods and the cell line adhesion assay. Antimicrobial susceptibility testing was determined using disk diffusion method. The presence of virulence factors and ESBL resistance genes were determined by polymerase chain reaction.

Results

Overall, 28.1% (9/32) of the isolates were positive for at least one of virulence genes. The most frequent gene was aap with a frequency of 96.9%. Neither aafA nor aggA gene was detected among all of the EAEC isolates. Antimicrobial susceptibility testing revealed the highest resistance rate to ampicillin (100%) and co-trimoxazole (100%), followed by ceftriaxone (81.3%). Further analysis revealed that the rate of ESBLs-producing isolates was 71.9% (23/32). Polymerase chain reaction screening revealed that 87.5% and 65.5% of EAEC isolates were positive for bla_TEM and bla_CTX-M genes, respectively, and 17 (53.1%) of isolates contained both bla_TEM and bla_CTX-M genes.

Conclusion

The high detection rate of ESBL-producing EAEC isolates accompanied with virulence genes highlights a need to restrict infection control policies in order to prevent further dissemination of the resistant and virulent EAEC strains.

Emerge of blaNDM-1 and blaOXA-48-like harboring carbapenem-resistant Klebsiella pneumoniae isolates from hospitalized patients in southwestern Iran

BACKGROUND

One of the most important emerging carbapenem-resistant bacteria is Klebsiella pneumoniae (K. pneumoniae). The present study aimed to investigate the antibiotic susceptibility pattern of K. pneumoniae isolates and detection of carbapenemase producing K. pneumoniae obtained from Iranian hospitalized patients.

METHODS

This cross-sectional study was performed on 211 K. pneumoniae isolates which were recovered from different clinical specimens from 2014 to 2015. Modified Hodge test (MHT) and double disk synergy test (DDST) were done for detection of carbapenemase and metallo-beta-lactamase (MBL) producing K. pneumoniae. The presence of antibiotic resistance determinants was investigated by polymerase chain reaction (PCR) method.

RESULTS

The results of antibiotic susceptibility showed that all isolates were resistant to ampicillin, and then mostly resistant to piperacillin and ceftazidime with 76.3% and 66.8%, respectively. On the other hand, the highest sensitivity was toward polymyxin B, followed by carbapenems. Of 29 carbapenem-resistant isolates, all were high-level imipenem-resistant isolates (Minimum inhibitory concentration ≥4), except 4 isolates. The results of MHT and DDST showed that 93.1% (27/29) of carbapenem-resistant isolates were carbapenemase and MBL producing isolates, respectively. The presence of bla_NDM-1 and bla_OXA-48-like genes was detected in 27 (10.9%) and 2 (0.9%) isolates, respectively.

CONCLUSION

This is the first identification of bla_NDM-1 and bla_OXA-48-like in K. pneumoniae in Southwestern Iran and the highest reported prevalence of bla_NDM in this bacterium from Iran. Since carbapenem-resistant isolates containing New Delhi metallo-beta-lactamase 1 (NDM-1) were almost resistant to all the tested antibiotics, the resistance due to this gene may be increased in the near future as a potential health threat.

Detection of Antimicrobial Susceptibility and Integrons Among Extended-spectrum β-lactamase Producing Uropathogenic Escherichia coli Isolates in Southwestern Iran

Objectives

Urinary tract infections (UTIs) are one of the most prevalent infectious diseases and can lead to a high rate of morbidity and mortality. The emergence of multiple-drug resistant strains, particularly extended-spectrum beta-lactamases (ESBLs) producing strains, has become a global healthcare concern. Our study sought to investigate the antimicrobial resistance pattern and presence of integrons and fimH determinants among uropathogenic Escherichia coli (UPEC) isolates obtained from hospitalized Iranian patients.

Methods

This cross-sectional study was performed on 121 E. coli isolates recovered from patients with clinical symptoms of UTIs, referred to Shiraz Nemazee Hospital, in 2016-17. The isolates were identified by standard microbiologic tests and confirmed by API 20E strip. Antimicrobial susceptibility testing was determined using the disk diffusion method. The presence of fimH and classes 1-3 integron encoding genes was determined using the polymerase chain reaction.

Results

Ampicillin (9.1%) and nalidixic acid (19.0%) showed the lowest level of antibiotic susceptibility. The highest level of susceptibility was toward imipenem (77.7%). The rate of ESBL-producing isolates was 42.1%. There was a significant association between production of ESBLs and higher antibiotic resistance in the tested isolates. Of the investigated virulence and resistance genes, fimH, intI1, and intI2 were positive in 98.3%, 59.5%, and 7.4% of isolates, respectively.

Conclusions

The remarkable rate of ESBL-producing UPEC isolates accompanied with the presence of integrons suggest the necessity of restricted infection control policies to prevent further dissemination of resistant strains.

Molecular epidemiology and characteristics of 16 cases with Stenotrophomonas maltophilia bacteraemia in pediatric Intensive Care Units

BACKGROUND

Recently, Stenotrophomonas maltophilia has increasingly been reported as an important nosocomial opportunistic pathogen. Limited therapeutic options of S. maltophilia infections demand early identification and knowledge about the probable risk factors for controlling its spread.

STUDY DESIGN

The present study aimed to investigate the risk factors and trend of antibiotic susceptibility, along with genetic analysis in bacteraemia cases at pediatric intensive care units (PICUs).

METHODS

A total of 16 S. maltophilia isolates were obtained, during 4 months from August to November 2015, from blood cultures of patients admitted to PICUs at Nemazee teaching hospital, Shiraz, Iran. S. maltophilia isolates were identified by conventional tests and confirmed by specific PCR primers. Minimum inhibitory concentrations (MICs) were determined by the MIC strip test as described by the Clinical and Laboratory Standards Institute's (CLSI) recommendation. The genetic relatedness among the isolates was assessed by ERIC-PCR.

RESULTS

All isolates of S. maltophilia were susceptible to ciprofloxacin, co-trimoxazole and colistin, and only 1 (6.2%) isolate was resistant against ceftazidime. The MIC50/MIC90 of ciprofloxacin, trimethoprim/sulfamethoxazole, colistin and ceftazidime was 0.25/0.38 mg/mL, 0.125/0.19 mg/mL, 0.25/0.38 mg/mL, and 2/4 mg/mL, respectively. Genotypic analysis of ERIC-PCR results revealed two distinct types of pattern. Interestingly, the only ceftazidime resistant isolate showed different patterns with other isolates.

CONCLUSIONS

Our findings indicated the importance of routine surveillance in infection control, since early detection of pathogens prevented the spread of nosocomial infections and granted effectiveness to care practices. Moreover, the results suggest that the routine drug of choice for S. maltophilia was mostly active against clinical isolates in our region.

Comparison of antimicrobial effects of titanium tetrafluoride, chlorhexidine, xylitol and sodium fluoride on streptococcus mutans: An in-vitro study

Introduction

No studies have yet documented the bactericidal effects of TiF4, and its role in the treatment of dental caries, and no definite protocol has been introduced to regulate its use. The aim of this study was to determine the antimicrobial/bactericidal effects of TiF4 on Streptococcus Mutans (S. Mutans) and to compare it with chlorhexidine (Chx), sodium fluoride (NaF) and xylitol.

Methods

This study was conducted at the Shiraz University of Medical Sciences microbiology laboratory during March 2015 to September 2015. In this in-vitro study, first a bacterial suspension was prepared and adjusted to a 0.5 McFarland standard (equivalent to 1×10⁸ CFU/ml). The minimal inhibitory concentration (MIC) and minimal bactericidal concentrations (MBC) of TiF4, Chx, NaF and xylitol were assessed using broth microdilution assay and disk diffusion methods. In order to neutralize the acidic nature of TiF4, we used a sodium hydroxide preparation to obtain a pH of 7.2 and repeated all of the previous tests with the neutralized TiF4 solution. We reported the final results as percentages where appropriate.

Results

The MIC of TiF4, NaF and Chx for S. Mutans were 12.5%, 12.5% and 6.25%, respectively. At a concentration of 12.5% the inhibition zone diameters were 9 mm, 15mm and 14mm for TiF4, NaF and Chx, respectively. The MBC was 25%, 12.5% and 12.5% for TiF4, NaF and Chx, respectively. Xylitol failed to show any bactericidal or growth inhibitory effect in all of its concentrations. When we repeated the tests with an adjusted pH, identical results were obtained.

Conclusion

TiF4 solutions have anti-growth and bactericidal effects on S. Mutans at a concentration of 12.5% which is comparable with chlorhexidine and NaF, indicating the possible use of this solution in dental practice as an anti-cariogenic agent, furthermore the antimicrobial activity is unaffected by pH of the environment.

High Incidence of Virulence Factors Among Clinical Enterococcus faecalis Isolates in Southwestern Iran

Background

Over the past two decades, enterococci have emerged as an important agent responsible for hospital acquired infection. Several virulence factors contribute to the adherence, colonization, evasion of the host immune response, and pathogenicity and severity of the infection. Enterococcus faecalis is the most common and virulent species causing infections in hospitalized patients. The aim of the present study was to examine the prevalence of genes encoding virulence factors and antimicrobial resistance patterns of E. faecalis strains isolated from hospitalized patients in Shiraz, south west of Iran.

Materials and Methods

A total of 51 E. faecalis isolates from the urine, blood, pleural fluid, peritoneal fluid, eye discharge, endotracheal tube (ETT) and transjugular intrahepatic portosystemic shunt (TIPS) specimens of patients were identified by phenotypic and genotypic methods. Antimicrobial sensitivity tests and detection of virulence factors were performed using standard methods.

Results

The efa and asa1 were the most frequently detected gene (100%) among the isolates, followed by esp (94.1%), ace (90.2%), gelE (80.4%), cylA (64.7%), and hyl (51%). More than half of the isolates (52.9%) were high level gentamicin resistant (HLGR). Vancomycin resistance was observed among 23 (45.1%) isolates. The lowest antimicrobial activity was related to erythromycin (3.9%), tetracycline (5.9%) and ciprofloxacin (9.8%). No isolate was found resistant to fosfomycin and linezolid.

Conclusion

Our data indicated a high incidence of virulence factors among E. faecalis strains isolated from clinical samples. Colonization of drug resistant virulent isolates in hospital environment may lead to life threatening infection in hospitalized patients. Therefore, infection control procedures should be performed.