CRISPR-like sequences association with antibiotic resistance and biofilm formation in Helicobacter pylori clinical isolates.

Role of clustered regularly interspaced short palindromic repeats (CRISPR)-like sequences in antibiotic resistance and biofilm formation isn't clear. This study investigated association of CRISPR-like sequences with antibiotic resistance and biofilm formation in H. pylori isolates. Thirty-six of H. pylori isolates were studied for existence of CRISPR-like sequences using PCR method and their correlation with biofilm formation and antibiotic resistance. Microtiter-plate technique was utilized for investigating antibiotic resistance profile of isolates against amoxicillin, tetracycline, metronidazole and clarithromycin. Biofilm formation of isolates was analyzed by microtiter-plate-based-method. Out of 23 CRISPR-like positive isolates, 19 had ability of biofilm formation and 7 of 13 CRISPR-like negative isolates were able to form biofilm (Pvalue = 0.445). In CRISPR-like positive isolates, 11 (48%), 18 (78%), 18 (78%) and 23 (100%) were resistant to amoxicillin, tetracycline, metronidazole and clarithromycin, respectively. Since CRISPR-like sequences have role in antibiotic resistance, may be applied as genetic markers of antibiotic resistance. But there was no substantial correlation between biofilm formation and existence of CRISPR-like sequences. These results indicate possible importance of CRISPR-like sequences on acquisition of resistance to antibiotics in this bacterium.

Molecular typing of clinical multidrug-resistant Klebsiella pneumoniae isolates.

INTRODUCTION: Klebsiella pneumoniae is an opportunistic pathogen which is an important cause of hospital-acquired and antibiotic resistance infections. Therefore, this study aimed to determine the frequency of resistance to antibiotics, as well as the molecular typing of the associated isolates, and compare multiple-locus VNTR analysis (MLVA) and Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR) methods to specify the degree to which distinctions can be separated from each other. METHODS AND MATERIALS: One hundred K. pneumoniae isolates were obtained from different sources of infections from patients admitted to hospitals. Antibiotic susceptibility testing was then performed by applying the Kirby-Bauer disk diffusion method. Typing of K. pneumoniae was done by utilizing MLVA and ERIC-PCR methods. RESULTS: Eighty-six multidrug-resistant (MDR) K. pneumoniae isolates were identified, which resistance to ampicillin, trimethoprim/sulfamethoxazole, and ceftriaxone was the most frequent in the considered isolates (100, 93, and 93%, respectively). A total of 50 different antibiotic susceptibility patterns were observed among the MDR K. pneumonia, with the most frequent pattern being resistance to all antibiotics (12.79%) and resistance to all antibiotics except amikacin (10.47%). The isolates were then divided into 37 different MLVA types and seven clonal complexes were obtained from the minimum spanning tree analysis. Finally, the isolates were assigned to 38 different ERIC types. The discriminatory power of MLVA and ERIC methods also showed a value of 0.958, and 0.974. CONCLUSION: Both PCR-typing methods with phenotypic patterns can be useful for the epidemiological typing of K. pneumoniae isolates with the highest performance in discriminating isolates.

Epidemiological characterization of clinical isolates of meticillin resistant Staphylococcus aureus through multilocus sequence typing and staphylococcal cassette chromosome mec typing in Northwest Iran.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA), is considered a potential and aggressive nosocomial pathogen. It accounts for 50% of S. aureus isolates in tertiary hospitals in Iran, however, there is no sufficient evolutionary and epidemiological investigation about this medically important bacterium. We aimed to study the lineage and evolution of MRSA in Northwest Iran during 2021-2022 based on the obtained phenotypic and genotypic characteristics. MATERIALS AND METHODS: Seventy-two non-duplicate MRSA isolates were collected from 3 referral hospitals in Tabriz, Ardebil, and Urmia cities. The antimicrobial susceptibility patterns were determined by disk diffusion test and micro broth dilution methods. Thereafter 4 virulence genes (eta, etb, pvl, tst) and 5 types of staphylococcal cassette chromosome mec (SCCmec) were detected by PCR. In the final step, representative isolates were selected to be studied by Multilocus sequence typing (MLST). RESULTS: The highest resistance was observed to erythromycin and clindamycin at a rate of 76.4%, followed by ciprofloxacin (61.1%), gentamicin (54.2%), rifampin (38.9%), and co-trimoxazole (27.8%). All isolates were susceptible to vancomycin. The virulence genes of etb, pvl, tst, and eta were detected in 50%, 29.2%, 21.8%, and 13.9% of isolates, respectively. SCCmec types III and I were the most prevalent types, followed by types IV, II, and V. MLST analysis revealed 6 sequence types: ST6854, ST5282, ST127, ST7804, ST1607, and ST7784. Two MLST-based clonal complexes (CC8, and CC97) were identified as well. CONCLUSION: The ST numbers were non-repetitive. CC8 as a pandemic clone and an individual lineage and clinically significant clade was reported as the most prevalent clonal complex. It is essential periodic evaluations of antibiotic susceptibility patterns and study the evolutionary characteristics of medical-challenging microorganisms in particular MRSA to effectively treat and restrict the outbreaks.

Interaction of the viral infectious agents in the development and exacerbation of the multiple sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system (CNS). The underlying cause of MS is still unknown. Multiple risk factors have been suggested that involve a combination of genetic, environmental, and infectious factors that contribute along with a weakened immune system. There is growing evidence supporting the potential role of viral infections in the development of the disease. Viruses like human immunodeficiency virus (HIV), John Cunningham virus (JCV), Varicella-Zoster virus (VZV), human herpesvirus 6 (HHV-6), Epstein-Barr virus (EBV), and human endogenous retroviruses (HERVs) have been proposed in the pathogenesis of MS. Their pathogenetic mechanisms are not well known, but several possibilities have been discussed. The present study highlights the proposed potential molecular and genetic mechanisms underlying this viral interaction and its implications for the development of MS.

Comparison of global decolonization efficacy with mupirocin nasal drop and chlorhexidine mouthwash in acute leukemia patients: randomized clinical trial.

PURPOSE: Neutropenic fever remains a major complication in acute leukemia. Decolonization is assumed as a promising intervention for eradicating causative agents of infection. METHODS: In this randomized clinical trial, 96 patients with acute leukemia were assigned randomly to mupirocin nasal drop 2% (n = 32), chlorhexidine mouthwash 0.2% (n = 33), and control group (n = 31). In control group, patients did not receive any medication for decolonization. All patients received treatment for 5 days (2 days prior to chemotherapy until 3 days after chemotherapy). Pharynx and nasal swabs were taken prior to the intervention and at the end of decolonization period in all groups. Antibiotic susceptibility testing was performed by the disc diffusion method in order to identify bacterial isolates. RESULTS: Bacterial recovery of both nasal and pharynx swabs was observed after global decolonization with mupirocin nasal drop. Decolonization with mupirocin significantly eradicated Coagulase-negative staphylococci (CONS) in both nasal and pharynx swabs (p-value = 0.000). Moreover, mupirocin decreased Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) species. Chlorhexidine mouthwash significantly eradicated CONS in pharynx swabs (p-value = 0.000). In addition, both decolonization strategies decreased both antibiotic use and frequency of fever in leukemic patients. CONCLUSION: Global decolonization with mupirocin nasal drop not only eradicates both nasal and pharynx microorganisms, but also reduces antibiotic requirement and frequency of fever in patients with acute leukemia. The protocol of the present study was approved on December 2016 (registry number: IRCT20160310026998N6).

Effect of 20-ppm ozone and 1% chlorhexidine gels on plaque index and Streptococcus mutans counts in the dental plaque in 6-12-year-old children: A randomized, double-blind clinical trial.

Background: One of the methods to control dental caries is to use ozone. Since it is difficult for children to use mouthwashes, the present study aimed to evaluate 20-ppm zone and 1% chlorhexidine (CHX) gels' effects on the plaque index and Streptococcus mutans counts in 6-12-year-old children. Methods: In the present double-blind clinical trial, 165 children, 6-12 years of age, referring to the Department of Pediatric Dentistry, Tabriz Faculty of Dentistry, were selected based on inclusion and exclusion criteria and randomly assigned to three groups: ozone gel, CHX gel, and control. The subjects were instructed to place an adequate amount of the gels on all the surfaces of their teeth with one clean finger. The patients and evaluators were blinded to the study groups. The plaque index and S. mutans counts in plaque samples were determined before intervention and three weeks after intervention on the buccal surface of the most posterior maxillary tooth (left or right). S. mutans counts were determined by culture. STATA software version 14 was used for statistical analyses using Wilcoxon, Kruskal-Wallis, and post hoc Dum tests. Statistical significance was defined at P<0.05. Results: The 20-ppm ozone and 1% CHX gels significantly decreased dental plaque compared to the control group (P<0.05), and their effects were similar (P>0.05). These gels significantly decreased the colonies and bacterial counts of S. mutans (P<0.05). Conclusion: The performance of 20-ppm ozone gel in decreasing the dental plaque and S. mutans counts was similar to 1% CHX gel.

The profile of key gut microbiota members and short-chain fatty acids in patients with sepsis.

Sepsis is a complex clinical disorder with heterogeneous etiological factors. Given its high mortality rate, it is considered a global health issue. Recently, the link between gut microbiota and their metabolites, especially short-chain fatty acids, in the pathophysiology of sepsis has been reported. However, there are few findings to confirm this relationship. This study aimed to evaluate some key gut microbiota members, pathogenic bacteria, and short-chain fatty acids in non-ICU patients with sepsis caused by bacteremia compared to a control group. In this case-control study, 45 stool samples from patients with sepsis and 15 healthy persons were collected from October 2021 to August 2022 in Tabriz, Iran. The position of some gut microbiota members and the main short-chain fatty acids concentration were assessed in the two groups by the Q-PCR and the high-performance liquid chromatography system. Faecalibacterium prausnitzii and Bifidobacterium sp. As bacterial with protective features in non-ICU patients with sepsis decreased significantly. Moreover, the concentrations of acetic acid and propionic acid significantly decreased in this group compared to the healthy volunteers. In contrast, the pathogenic bacteria members such as Enterobacteriaceae and Bacteroides sp. Increased significantly in the patients compared to the healthy individuals. The concentration of butyric acid decreased in the patients, but this change was not significant in the two groups. Protective and immune functions of F. prausnitzii and Bifidobacterium sp., as well as acetate and propionate, are evident. In this investigation, this profile was significantly reduced in non-ICU patients with sepsis compared to the control group.

Genetic diversity of Mycobacterium tuberculosis isolates from northwest of Iran during COVID-19 era.

Background: Tuberculosis (TB) is considered one of the most infectious diseases in the world. In this study, we intended to examine the epidemiology of tuberculosis by MIRU-VNTR to define the changes that occur in the transmission of tuberculosis in the region during the COVID-19 era. A total of 120 Mycobacterium tuberculosis isolates were collected from sputum samples of patients referred to East Azerbaijan Center TB from December 2020 to August 2021. Demographic information such as age, sex, place of birth, previous TB history, and relevant medical data was collected. The proportion method was performed for drug susceptibility testing, and the PCR-based MIRU-VNTR method was applied to identify molecular epidemiology relationships. Results: The isolates were collected from 78 male (65%) and 39 female (32.5%) Iranian patients and 3 (2.5%) Azerbaijani patients. Ninety-three distinct patterns were identified including 15 clustered patterns and 36 unique patterns. The largest cluster was composed of seven isolates. Furthermore, one cluster with 5 members, four clusters with 3 members, and nine clusters with 2 members. In MIRU-VNTR typing, 75 clusters belonged to the Tabriz region and just 3 to the Republic of Azerbaijan. All isolates were sensitive to rifampin, isoniazid, and ethambutol. Conclusions: Results of the current study showed COVID-19 pandemic had a direct effect on the transmission and diagnosis of tuberculosis. Less diagnosis and less clustering can indicate public controls and hygiene, and the use of masks had a direct effect on the transmission and diagnosis of tuberculosis. However, misidentification and less focus on other respiratory infections are expected during the pandemic. Studies on the co-infection of COVID-19 and tuberculosis and the role of mask and sanitization against TB are strongly recommended.

Gut microbiota and obesity: an overview of microbiota to microbial-based therapies.

The increasing prevalence of obesity and overweight is a significant public concern throughout the world. Obesity is a complex disorder involving an excessive amount of body fat. It is not just a cosmetic concern. It is a medical challenge that increases the risk of other diseases and health circumstances, such as diabetes, heart disease, high blood pressure and certain cancers. Environmental and genetic factors are involved in obesity as a significant metabolic disorder along with diabetes. Gut microbiota (GM) has a high potential for energy harvesting from the diet. In the current review, we aim to consider the role of GM, gut dysbiosis and significant therapies to treat obesity. Dietary modifications, probiotics, prebiotics, synbiotics compounds, using faecal microbiota transplant, and other microbial-based therapies are the strategies to intervene in obesity reducing improvement. Each of these factors serves through various mechanisms including a variety of receptors and compounds to control body weight. Trial and animal investigations have indicated that GM can affect both sides of the energy-balancing equation; first, as an influencing factor for energy utilisation from the diet and also as an influencing factor that regulates the host genes and energy storage and expenditure. All the investigated articles declare the clear and inevitable role of GM in obesity. Overall, obesity and obesity-relevant metabolic disorders are characterised by specific modifications in the human microbiota's composition and functions. The emerging therapeutic methods display positive and promising effects; however, further research must be done to update and complete existing knowledge.

Uropathogenic Escherichia coli endeavors: an insight into the characteristic features, resistance mechanism, and treatment choice.

Uropathogenic Escherichia coli (UPEC) are the strains diverted from the intestinal status and account mainly for uropathogenicity. This pathotype has gained specifications in structure and virulence to turn into a competent uropathogenic organism. Biofilm formation and antibiotic resistance play an important role in the organism's persistence in the urinary tract. Increased consumption of carbapenem prescribed for multidrug-resistant (MDR) and Extended-spectrum-beta lactamase (ESBL)-producing UPECs, has added to the expansion of resistance. The World Health Organization (WHO) and Centre for Disease Control (CDC) placed the Carbapenem-resistant Enterobacteriaceae (CRE) on their treatment priority lists. Understanding both patterns of pathogenicity, and multiple drug resistance may provide guidance for the rational use of anti-bacterial agents in the clinic. Developing an effective vaccine, adherence-inhibiting compounds, cranberry juice, and probiotics are non-antibiotical approaches proposed for the treatment of drug-resistant UTIs. We aimed to review the distinguishing characteristics, current therapeutic options and promising non-antibiotical approaches against ESBL-producing and CRE UPECs.

Interaction Between Altered Gut Microbiota and Sepsis: A Hypothesis or an Authentic Fact?

Sepsis, as an important public health concern, is one of the leading causes of death in hospitals around the world, accounting for 25% of all deaths. Nowadays, several factors contribute to the development of sepsis. The role of the gut microbiota and the response state of the aberrant immune system is dominant. The effect of the human microbiome on health is undeniable, and gut microbiota is even considered a body organ. It is now clear that the alteration in the normal balance of the microbiota (dysbiosis) is associated with a change in the status of immune system responses. Owing to the strong association between the gut microbiota and its metabolites particularly short-chain fatty acids with many illnesses, the gut microbiota has a unique position in the research of microbiologists and even clinicians. This review aimed to analyze studies' results on the association between microbiota and sepsis, with a substantial understanding of their relationship. As a result, an extensive and comprehensive search was conducted on this issue in existing databases.

The Prevalence and Antibiotics Susceptibility Patterns of Corynebacterium minutissimum Isolates from Skin Lesions of Patients with Suspected Erythrasma from Tabriz, Iran.

Erythrasma is a chronic infection of the skin that appears in the body folds as flat copper spots. The causative agent of this infection is Corynebacterium minutissimum (C. minutissimum). Erythrasma can be treated with antiseptics or topical antibiotics. The study aimed to investigate the antibiotics susceptibility patterns, and the presence of the erythromycin resistance gene (ermX and mefA) in C. minutissimum isolates in skin lesions with suspected erythrasma. From July 2020 to May 2022, 278 skin scrub specimens were collected from patients admitted to the hospital of Tabriz University of Medical Sciences. Specimens were incubated on the blood agar plates and isolates were identified by microbiological laboratory methods. The antibiotic susceptibility patterns were determined by the disk diffusion method and resistance genes of ermX and mefA were detected by the PCR method. Out of 278 specimens, 41 C. minutissimum isolates (14.74%) were recovered. The highest frequency of resistance was observed to a penicillin (75.6%) followed by erythromycin and clarithromycin (39.02%), clindamycin (30.05%), tetracycline (24.2%), and gentamicin and neomycin (19.5%). The frequencies of ermX and mefA genes were 75% and 12.5%, respectively. Resistance to antimicrobial drugs was common and worrying. Resistance to erythromycin in C. minutissimum is mainly related to the ermX gene.

Contribution of Arginine Catabolic Mobile Element and Copper and Mercury Resistance Element in Methicillin-Resistant Staphylococcus aureus: A Vantage Point.

Different clones of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are dominating geographically. One of the significant, hypervirulent, CA-MRSA and a significant health concern clones is USA3000, found worldwide regionally with varying frequencies. The clone harbors several mobile genetic elements (MGEs) including, arginine catabolic mobile element (ACME) and copper and mercury resistance genes (COMER), accomplished by horizontal gene transfer from S. epidermidis. Evidence suggests that ACME and COMER have a more prominent role in enhancing biofilm capacity and ultimately persistent infections. This review highlights the comprehensive view on ACME and COMER structure, their distribution, and the mechanism of action along with pathogenetic features of USA3000 encompassing their role in biofilm formation, adhesion, quorum sensing, resistance to antibiotics, chemotaxis, and nutrient uptake. We also provided an insight into the role of ACME and COMER genes in the survival of bacterium. Our results shed light on the emergence of two independent clones possessing ACME (North American) and COMER (South American) elements which later disseminated to other regions. ACME and COMER both are adjacent to staphylococcal cassette chromosome mec type IV (SCCmec IV). The acquisition of mecA, followed by COMER or ACME has been shown as a significant factor in the rise and fall of MRSA strains and their complex ability to adapt to hostile environments. The presence of ACME increases fitness, thereby allowing bacteria to colonize the skin and mucous membrane while COMER contributes to genetic stability by knocking over the copper-mediated killing in macrophages. Evidence suggests that ACME and COMER have a more prominent role in enhancing biofilm capacity and ultimately persistent infections. Interestingly, ACME strains have been shown to possess the ability to counteract skin acidity, thereby allowing increased skin colonization. A profound understanding of MGEs in S. aureus plays an important role in the prevention of epidemic clones.

Occult Hepatitis B Infection among Hemodialysis in Tabriz, Northwest of Iran: Prevalence and Mutations within the S Region.

Regardless of the extensive screening for the detection of hepatitis B surface antigen (HBsAg), hemodialysis (HD) patients are still severely at the risk of occult hepatitis B virus infection (OBI), especially in developing countries. OBI is defined as the presence of HBV DNA with undetectable HBsAg in the liver and/or Serum. This study aims to determine the prevalence of OBI in HD patients in Tabriz Province, northwest of Iran, and inquire about the mutations in the detected HBsAg. In this cross-sectional descriptive study, ELISA method assessed serum and plasma samples of 118 HBsAg-negative patients undergoing HD treatment for HBV serological markers (HBsAg and Anti-HBc). Specific primers by nested polymerase chain reaction have been utilized to examine HBV DNA; also, direct sequencing of surface genes was carried out to characterize the viral genotypes and S gene mutations. Finally, followed by real-time PCR, the quantity of viral load in OBI-positive patients was determined. A total of 118 HD patients were included (63.6% were male and 36.4% female), with an overall mean age of 60.8 ± 12.8 years old. The prevalence of antihepatitis B core antibody (Anti-HBc) in the study population was 26.3% (31/118). Five patients (4.2%) were positive for HBV DNA and labeled OBI-positive; their plasma HBV-DNA load was less than 100 IU/ml. Following the phylogenetic analysis, the samples with OBI roughly belonged to genotype D, subtype ayw2 and only two had mutations within the S 'gene's major hydrophilic region (MHR), including T123I, C124F, and P127T. This study reports the prevalence of OBI in the HBsAg-negative HD patients being at a rate of 4.2%, which can be a clinically vital consideration in this region. HBV serologic screening approaches need to be renewed to cover nucleic acid testing in the setting of hemodialysis and all the other high-risk groups associated with it (i.e., blood and organ donors).

Evidence of High-Risk Human Papillomavirus in Esophageal Cancer in East Azerbaijan Province, Northwest of Iran.

BACKGROUND: Human papillomavirus (HPV) is one of the most important viral agents associated with several classes of cancers in humans. The aim of this study was to investigate HPV in esophageal cancer in the East Azerbaijan province, northwest of Iran. METHODS: 140 paraffin-embedded specimens of esophageal tissues were investigated using nested-polymerase chain reaction (nested-PCR) with primer designing for the L1 region of HPV genome. According to the pathological diagnosis, the samples were divided into two groups: 70 patients with esophageal cancer EADC (n = 35) and ESCC (n = 35) as the case group and those without tumour in esophagus tissue as a control (n = 70). RESULTS: HPV DNA was isolated from 20 (28.57%) of the 70 paraffin-embedded tissue specimens of esophagus cancer. Of these, 6 cases (17.14%) of EADC and 14 cases (40%) of ESCC were positive. In contrast, all cases of the control group were negative for the HPV genome. Sequence analysis revealed that HPV types 16 and 18 are the most frequent ones identified in this study. CONCLUSION: The prevalence of HPV in esophageal cancer can vary depending on the geographical location and other factors. Based on the findings of this study, HPV infection may possibly have contributed to an increased risk of esophageal cancer in a group of patients in Tabriz.

Evaluation of Human Respiratory Syncytial Virus and Human Parainfluenza Virus Type 3 among Hospitalized Children in Northwest of Iran.

BACKGROUND: Acute respiratory tract infections (ARTIs) are the leading cause of illnesses in children. Human respiratory syncytial virus (HRSV) and human parainfluenza viruses (HPIVs) are among the most common etiologic agents associated with viral respiratory tract infections in children worldwide. Nevertheless, limited information is available on the spread of infections of these two viruses in northwest Iran. OBJECTIVE: The purpose of the current study is to evaluate the frequency of RSV and HPIV-3 and clinical features among Iranian children with confirmed respiratory infections between April 2019 and March 2020. METHODS: 100 nasopharyngeal swabs were collected from hospitalized patients (under 5 years old) with ARTI from Tabriz Children's Hospital. Detection of respiratory viruses was performed using the nested RT-PCR method. RESULTS: Respiratory syncytial virus and HPIV-3 were recognized in 18% (18/100) and 2% (2/100) of children, respectively. Ten (55.6%) of the RSV-positive samples were male, while 8 (44.4%) were female. HPIV-3 was found only among 2 male patients (100%). Most patients (61.1%) with RSV infection were less than 12 months old. Additionally, samples that were positive for HPIV-3 were less than 12 months old. RSV infections had occurred mainly during the winter season. CONCLUSIONS: This study confirms that RSV can be one of the important respiratory pathogens in children in northwestern Iran. However, according to this study, HPIV-3 has a lower prevalence among children in this area than RSV. Therefore, implementing a routine diagnosis for respiratory pathogens can improve the management of respiratory infections in children.

Dysregulation of lncRNA in Helicobacter pylori-Infected Gastric Cancer Cells.

Helicobacter pylori (H. pylori) infection is the most common cause of gastric cancer (GC). This microorganism is genetically diverse; GC is caused by several genetic deregulations in addition to environmental factors and bacterial virulence factors. lncRNAs (long noncoding RNAs) are significant biological macromolecules in GC, have specific functions in diseases, and could be therapeutic targets. Altered lncRNAs can lead to the abnormal expression of adjacent protein-coding genes, which may be important in cancer development. Their mechanisms have not been well understood, so we are going to investigate the risk of GC in a population with both high lncRNA and H. pylori infection.

Comparison of superantigens and attachment factors genes of Staphylococcus aureus in clinical isolates and nasal colonizers in the same patients.

BACKGROUND: Staphylococcus aureus (S. aureus) is a bacterial pathogen can cause a wide range of nosocomial infections. Nasal colonization by S.aureus plays important role both in the epidemiology and pathogenesis of infection. OBJECTIVES: The purpose of this study was to investigate the association of clinical isolates and nasal colonizers of S. aureus in the same patients by molecular methods, and their antibiotic susceptibility pattern. METHODS: A total of 181 S. aureus isolates were collected from 100 patients admitted that including 100 clinical isolates and 81 nasal swabs from the same patients (19 cases were found as noncarriers). Superantigens and adhesion genes were identified by PCR. Molecular typing of the isolates was performed by repetitive element polymerase chain reaction (Rep-PCR). Antimicrobial susceptibility pattern of the isolates was conducted by disk diffusion. MIC of the isolates to vancomycin was determined by microbroth dilution. The ability of S. aureus isolates to form biofilm was determined by microtiter plate assay. RESULTS: The most frequent adhesion gene in both clinical isolates and nasal colonizer was clfA with 93% and 76%, respectively. Staphylococcal enterotoxin A (SEA) was the most commonly superantigen (68%) in both nasal colonizers (71.6%) and clinical isolates (65%). The highest resistance rate was to erythromycin (45.3%) with 36% and 56.8% in clinical and nasal colonizer isolates, respectively. All S. aureus isolates were susceptible to linezolid and vancomycin. Multiple drug resistance (MDR) was detected in 36% (n = 65) of the isolates. Biofilm formation was identified in 160 (88.4%) isolates with 87% and 90% in clinical isolates and nasal colonizers, respectively. Repetitive element polymerase chain reaction (Rep-PCR) typing divided 181 S. aureus isolates into six clusters. Twelve isolates from clinical isolates and nasal carriers were closely related. CONCLUSION: There is a high concordance rate between colonizing and clinical isolates of S. aureus in terms of adhesion factors and superantigen genes. It is suggested that nasal decolonization could be effective in the preventing of S. aureus infections.

Genetic characterization of extensive drug resistant Acinetobacter baumannii: an appalling impediment.

INTRODUCTION: Acinetobacter baumannii infections are a growing public-health concern. The bacterium's potentiality to acquire resistance to a number of commonly used antibiotics has turned it into a formidable pathogen. AIMS: Molecular characterization of extensive drug resistant (XDR) typing of A. baumannii clinical isolates by polymerase chain reaction. MATERIALS AND METHODS: Thirty XDR A. baumannii were investigated for the presence of genes encoding carbapenemase resistance, biofilm capacity, autoinducer synthase, virulence and surface motility by polymerase chain reaction (PCR). Later, the isolates were typed by plasmid-based replicon (Rep) (PBRT) and trilocus sequence typing. RESULTS: All 30 XDR A. baumannii strains displayed genes related to surface motility, autoinducer synthase, virulence determinant, biofilm related genes except PER, and bap, the frequency of which was 83.3% and 76.6%, respectively. Analysis of rep genes showed highest frequency of rep6 and rep2 genes, with frequency of 75% and 65%, respectively. All XDR A. baumannii strains belonged to SG I (European clone II) group. CONCLUSIONS: Our results show the extraordinary plasticity of XDR A. baumannii and suggest that the strains have gained endemicity in our hospital, which could be a great concern in the near future.