Determine phenotypical patterns of resistance to antibiotics in COVID-19 patients with associated bacterial infection: largest medical center in Iran.

Background and Objectives: Antibacterial resistance (AMR) is a serious threat and major concern, especially in developing countries. Therefore, we aimed to determine phenotypical patterns of resistance to antibiotics in COVID-19 patients with associated bacterial infection in intensive care units. Materials and Methods: In this cross-sectional study, 6524 COVID-19 patients admitted for more than 48 h in the ICUs of Imam Khomeini Complex Hospital (IKCH) in Tehran from March 2020 to January 2022 were included in the study with initial diagnosis of COVID-19 (PCR test and chest imaging). Data were collected regarding severity of the illness, primary reason for ICU admission, presence of risk factors, presence of infection, length of ICU and hospital stay, microbial type, and antibiotic resistance. In this study, the pattern of antibiotic resistance was determined using the Kirby-Bauer disk diffusion method. Results: In this study, 439 (37.5%) were ventilator-related events (VAEs), and 46% of all hospitalized patients had an underlying disease. The most common microorganisms in COVID-19 patients were carbapenem resistant Klebsiella pneumoniae (KPCs) (31.6%), Escherichia coli (E. coli) (15.8%), and Acinetobacter baumannii (A. baumannii) (15.7%), respectively. Prevalence of vancomycin-resistant enterococci (VRE) and KPCs were 88% and 82%, respectively. Conclusion: A study on AMR surveillance is the need of the hour as it will help centers to generate local antibiograms that will further help formulate national data. It will guide doctors to choose the appropriate empiric treatment, and these studies will be the basis for establishing antimicrobial surveillance and monitoring and regulating of the use of antimicrobials.

Factors affecting the incidence of surgical site infections after geriatric hip fracture surgery: a retrospective study during 2017-2020.

INTRODUCTION: Geriatric hip fracture are a common and disruptive public health problem worldwide. Surgical Site Infection (SSI) can be a devastating complication of this injury. By identifying these factors, the adverse outcomes of elderly hip fractures can be prevented. The objective of this study was to identify factors affecting the incidence of surgical site infection after geriatric hip fracture surgery. METHODS: In this retrospective study, 440 patients (60 years or older) underwent hip surgery at Imam Khomeini Hospital Complex were selected based on census between April 2017 and March 2020. Demographics information, and additional comorbidities and operation-related variables were extracted and analyzed. Data analyses were performed by descriptive statistics and inferential statistics. SPSS-19 software was used in this study and P values less than 0.05 were considered significant. RESULTS: The results of univariate analyzes showed that the type of surgery (p=0.005), readmission (p=0.0001) and level of self-care (p=0.001) were significantly associated with Surgical Site Infection (SSI). The results of regression analysis showed that history of readmission and self-care at all levels on SSI. CONCLUSION: The findings showed that the history of readmission and self-care at all levels is effective on SSI in the elderly with hip fractures. Therefore, it can be concluded that by identifying the factors affecting the SSI with hip fractures, fewer acute complications, reduced death and shorter length of hospital stay.

Identification of Mycobacterium tuberculosis in pulmonary and extrapulmonary specimens of Iranian hospitalized patients during 2017-2021.

Background: Tuberculosis (TB) is one of the most serious public health problems worldwide which is a chronic infectious disease and is still one of the major challenges for developing countries. This study was undertaken to identify Mycobacterium TB (MTB) in clinical specimens in hospitalized patients. Methods: The study was carried out on specimens from pulmonary and extrapulmonary suspected TB patients that were admitted to one of the largest tertiary hospitals located in Tehran, Iran from 2017 to 2021. The GeneXpert MTB/rifampin (RIF) method was applied to detect MTB and RIF resistance. Characteristics of demography, clinical features, and lifestyle were obtained from medical case records registered in the hospital. Results: Of 957 specimens, 92 (9.61%) were found positive for TB by GeneXpert assay. Of positive samples, 72 (78.26%) were considered pulmonary TB, and 20 (21.73%) of them are associated with extrapulmonary involvement. Four (4.3%) positive TB cases were categorized as rifampicin-resistant. Conclusion: This study showed a relatively high incidence rate of TB in distinct types of specimens in Iranian hospitalized patients but a low level of RIF resistance.

Clinical and microbiological patterns in critically ill patients with catheter-associated UTI: A report from Iran.

INTRODUCTION: Catheter-associated urinary tract infections (CAUTIs) are among the most common nosocomial infections with different clinical and microbiological characteristics. We studied these characteristics in critically ill patients. METHODOLOGY: This research was a cross-sectional study conducted on intensive care unit (ICU) patients with CAUTI. Patients' demographic and clinical information and laboratory data, including causative microorganisms and antibiotic susceptibility tests, were recorded and analyzed. Finally, the differences between the patients who survived and died were compared. RESULTS: After reviewing 353 ICU cases, 80 patients with CAUTI were finally included in the study. The mean age was 55.9 ± 19.1 years, 43.7% were male and 56.3% were female. The mean length of infection development since hospitalisation and hospital stay were 14.7 (3-90) and 27.8 (5-98) days, respectively. The most common symptom was fever (80%). The microbiological identification showed that the most isolated microorganisms were Multidrug-resistant (MDR) Enterobacteriaceae (75%), Pseudomonas aeruginosa (8.8%), Gram-positive uropathogens (8.8%) and Acinetobacter baumannii (5%). Fifteen patients (18.8%) died among whom infections with A. baumannii (75%) and P. aeruginosa (57.1%) were associated with more death (p = 0.005). CONCLUSIONS: Although A. baumannii and P. aeruginosa can be the most important pathogens for death, MDR Enterobacteriaceae are still a serious concern as causes of CAUTIs.

Antibiotic use during the first 6 months of COVID-19 pandemic in Iran: A large-scale multi-centre study.

WHAT IS KNOWN AND OBJECTIVE: Although antibiotics are ineffective against viral infections, epidemiological studies have revealed that the COVID-19 pandemic resulted in the overuse of antibiotics and disruption of antimicrobial stewardship programmes. We investigated the pattern of antibiotic use during the first 6 months of the COVID-19 pandemic in Iran. METHODS: A multi-centre retrospective study was designed to investigate the use of 16 broad-spectrum antibiotics in 12 medical centres. The rate of antibiotic use was calculated and reported based on the Defined Daily Dose (DDD) per 100 hospital bed-days. The bacterial co-infection rate was also reported. RESULTS AND DISCUSSION: Totally, 43,791 hospitalized COVID-19 patients were recruited in this study. It was found that 121.6 DDD of antibiotics were used per 100 hospital bed-days, which estimated that each patient received approximately 1.21 DDDs of antibiotics every day. However, the bacterial co-infections were detected only in 14.4% of the cases. A direct correlation was observed between the rate of antibiotic use and mortality (r[142] = 0.237, p = 0.004). The rate of antibiotic consumption was not significantly different between the ICU and non-ICU settings (p = 0.15). WHAT IS NEW AND CONCLUSION: In this study, widespread antibiotic use was detected in the absence of the confirmed bacterial coinfection in COVID-19 patients. This over-consumption of broad-spectrum antibiotics may be associated with increased mortality in hospitalized COVID-19 patients, which can be an alarming finding.

Bilateral hip septic arthritis caused by nontyphoidal Salmonella group D in a 16-year-old girl with COVID-19: A case report.

INTRODUCTION AND IMPORTANCE: Nontyphoidal Salmonella infection can lead to gastroenteritis, enteric fever, and bacteremia. However, joint infections due to this bacterium are rare, and usually associated with immunosuppressive disorders. CASE PRESENTATION: A 16-year-old girl, with a recent history of acute lymphocytic leukemia (ALL) presented with bacteremia, and bilateral hip pain after COVID-19 symptoms. Clinical presentation, laboratory features and imaging showed bilateral nontyphoidal Salmonella septic arthritis. We administered antibiotics, based on antibiotics susceptibility pattern of the isolated Salmonella. CLINICAL DISCUSSION: The case is presented because reports of bilateral hip joint infection due to nontyphoidal Salmonella are rare especially after COVID-19. When the patient presents with joint discomfort, the clinician should think infection especially in immunocompromised hosts. CONCLUSION: It illustrates successful management of septic arthritis requires prompt clinical diagnosis, microorganism identification, administration of appropriate systemic antibiotics and hip joint surgery.

Characterization of bacteriocins produced by Lactobacillus species against adhesion and invasion of Listeria monocytogenes isolated from different samples.

BACKGROUND: Listeria monocytogenes is an important difficult to control and eradicate foodborne pathogen due to its resistance properties to extreme conditions. Bacteriocins produced by lactic acid bacteria (LAB) can be considered as natural alternatives for safety and quality of foods, since these molecules offer antimicrobial activity against other bacteria. METHODS: In this study, Lacticaseibacillus casei, Lactiplantibacillus plantarum, and L. monocytogenes isolates were first characterized by phenotypical tests and 16S rRNA gene using PCR. Then, six types of bacteriocins produced by Lactobacilli strains were identified using molecular tests. The ability of these strains to compete with L. monocytogenes for adhesion and invasion to HT-29 cells was evaluated through colony count and MTT assay. Finally, the level of bacteriocins expression was assessed using qRT-PCR. RESULTS: L. monocytogenes strains were categorized from A1 to A8 based on the source of isolation. In the adhesion assay, L. casei + L. monocytogenes isolated from milk and Lpb plantarum + L. monocytogenes isolated from feces presented the maximum adherence values. Further, Lpb plantarum + L. monocytogenes isolated from blood invaded to HT-29 cell line at the highest level. Eventually, L. casei + Lpb plantarum + L. monocytogenes isolated from placenta revealed more expression levels in comparison with other groups. CONCLUSION: These results suggest a practical approach to classifying bacteriocins into functional groups that could be used for identifying the best mixture of bacteriocins for usage against L. monocytogenes.

Co-infection of ST2IP carbapenem-resistant Acinetobacter baumannii with SARS-CoV-2 in the patients admitted to a Tehran tertiary referral hospital.

BACKGROUND: Carbapenem-resistant Acinetobacter baumannii (CRAB) is among the most concerning cause of healthcare-associated infections (HAI) due to its high level of antibiotic resistance and high mortality. In the era of the COVID-19 pandemic, the key priority of infection control committees is to contain the dissemination of antibiotic resistant Gram-negative bacteria. Here, we aimed to timely recognize the emergence of CRAB in COVID-19 cases admitted to the wards of a tertiary referral hospital and to identify the genetic relatedness of the isolates. METHODS: From 30 March to 30 May 2020, a total of 242 clinical samples from COVID-19 cases were screened for CRAB isolates using standard microbiologic and antibiotic susceptibility tests. The PCRs targeting oxa23, oxa24, oxa58, blaTEM and blaNDM-1 genes were performed. Two multiplex PCRs for identifying the global clones (GC) of A. baumannii were also performed. The sequence type of CRABs was determined using Institut Pasteur (IP) multilocus sequence typing (MLST) scheme. RESULTS: Eighteen CRAB isolates were recovered from COVID-19 patients with the mean age of 63.94 ± 13.8 years. All but 4 COVID-19 patients co-infected with CRAB were suffering from an underlying disease. Death was recorded as the outcome in ICUs for 9 (50%) COVID-19 patients co-infected with CRAB. The CRAB isolates belong to GC2 and ST2IP and carried the oxa23 carbapenem resistance gene. CONCLUSION: This study demonstrated the co-infection of CRAB isolates and SARS-CoV-2 in the patients admitted to different ICUs at a referral hospital in Tehran. The CRAB isolates were found to belong to ST2IP, share the oxa23 gene and to have caused several outbreaks in the wards admitting COVID-19 patients.

Proven pulmonary aspergillosis in a COVID-19 patient: A case report.

BACKGROUND AND PURPOSE: Coronavirus disease 2019 (COVID-19) has become a significant clinical challenge in healthcare settings all over the world. Critically ill COVID-19 patients with acute respiratory distress syndrome may be at increased risk of co-infection with pulmonary aspergillosis. This study aimed to describe a clinical case of proven pulmonary aspergillosis caused by Aspergillus tubingensis in a 59-year-old man with a history of hospitalization due to COVID-19 infection. CASE REPORT: The Covid-19 infection was confirmed by positive nasopharyngeal polymerase chain reaction. He had a cavitary lesion measured 20 mm in diameter with intracavitary soft tissue density in the left lung in the first chest computerized tomography scan. After 25 days, he showed two cavitary lesions in both lungs which raised suspicion of fungal infection; hence, the patient underwent a trans-thoracic biopsy of the cavitary lesion. The direct examination and culture of the biopsy material revealed Aspergillus species. To confirm the Aspergillus species identification, the beta-tubulin region was sequenced. The patient was treated with oral voriconazole. CONCLUSION: This report underlined the importance of early diagnosis and management of invasive fungal infections in severe COVID-19 patients.

Isolation and characterization of a multidrug-resistant Clostridioides difficile toxinotype V from municipal wastewater treatment plant.

PURPOSE: Wastewater treatment plant (WWTP) is regarded as a potential source for transmission of Clostridioides difficile from urban areas into the surface water, through feces of human and animals. The aim of this study was to screen and characterize the C. difficile bacteria in inlet and outlet wastewater of different WWTPs in Tehran, Iran. METHODS: Totally, 72 samples were collected from three different WWTPs (inlet site and outlet sites) during a year. C. difficile was isolated and characterized in terms of toxins, toxinotype, resistance profile and genes, and colonization factors using PCR. RESULTS: One C. difficile toxinotype V was isolated from the outlet samples. The isolate was susceptible to vancomycin but resistant to metronidazole, tetracycline, ciprofloxacin, and moxifloxacin using MIC Test Strips. The isolated C. difficile was toxigenic (tcdA, tcdB, cdtA, cdtB positive and CPE positive) and had tcdC-A genotype. No mutations were found in fliC and fliD. The slpA sequence type was 078 - 01. The C. difficile was positive for tetM, int, but negative for vanA, nim, and tndX genes. Mutations were not observed in gyrA and gyrB genes. CONCLUSIONS: This study provided evidence of presence of a multidrug-resistant C. difficile toxinotype V in one of the municipal WWTP. The transmission of such isolate to the environment and reuse of treated wastewater by human pose a threat to human health and dissemination of antibiotic resistant bacteria which are untreatable.

Polymorphisms in the genes encoding surface associated proteins of Clostridioides difficile isolates.

BACKGROUND: Although the diversity of Clostridioides difficile toxins have been extensively studied, little is known about the variation in the surface associated proteins (SAPs) which are important in early steps of bacterial colonization and infection. Here, we examined 65C. difficile isolates to identify polymorphisms in the genes encoding SAPs. METHODS: PCR was used to amplify slpA, fliC, fliD, cwp66 and cwp84 genes, followed by sequencing. In addition, the antigenicity and immunogenicity properties of different types of SlpA, FliC, FliD, Cwp66 and Cwp84 proteins were predicted in-silico by VaxiJen and BcePred online servers. RESULTS: The predominant slpA sequence type was gr-01 (42.37%), followed by hr-01 (11.86%) and 078-01 (10.16%). In addition, two new slpA subtypes of smz (smz-09-Ir and smz-010-Ir) and a new slpA sequence type (Ir-01) were identified among the isolates examined. Analysis of the nucleotide sequences of fliC, fliD, cwp66 and cwp84 genes revealed 7, 5,5,3 different sequence types, respectively. Insilico analysis of antigenicity of SAPs showed that FliC had the highest level of antigenicity whereas SlpA and Cwp66 proteins had the highest level of immunogenicity. CONCLUSIONS: This study pointed to the nucleotide polymorphism in SAPs of C. difficile isolates and demonstrated noticeable diversity in antigenicity and immunogenicity of these proteins which need to be taken into consideration as promising therapeutic or vaccine targets.

High prevalence of Clostridiodes diffiicle PCR ribotypes 001 and 126 in Iran.

Clostridium difficile is a leading causative agent of hospital-acquired and community-acquired diarrhea in human. This study aims to characterize the predominant C. difficile strains, RT001 and 126, circulating in Iranian hospitals in relation to resistant phenotypes, the antibiotic resistance genes, and their genetic relatedness. A total number of 735 faecal specimens were collected from patients suspected of CDI in Tehran hospitals. Typing and subtyping of the strains were performed using CE-PCR ribotyping and MLVA, respectively, followed by PCR assays for ARGs and indicators of Tns. Minimum inhibitory concentrations (MICs) of five antibiotics were determined by MIC Test Strips. Among 65 strains recovered from CDI patients, RT001 (32.3%) and RT126 (9.2%) were found as the most frequent ribotypes, and 64 MLVA types were identified. Using MLVA, RT001 and RT126 were subtyped into 6 and 4 groups, respectively. The vanA, nim, tetM, gyrA, gyrB genes were detected in 24.6%, 0%, 89.2%, 95.3%, and 92.3% of the strains, respectively. The indicators of Tns including vanHAX, tndX, and int were found in 0%, 3% and 29.2% of the strains, respectively. The most common amino acid (AA) alterations of GyrA and GyrB were related to substitutions of Thr82 → Val and Ser366 → Val, respectively. Resistance rate to metronidazole, vancomycin, tetracycline, ciprofloxacin, and moxifloxacin was 81.5%, 30.7%, 85%, 79%, and 74%, respectively. This study, for the first time revealed the subtypes of circulating RT001 and RT126 in Iran. It is of importance that the majority of the strains belonging to RT001 were multidrug resistant (MDR). This study also pointed to the intra-hospital dissemination of the strains belonging to RT001 and RT126 for short and long periods, respectively, using MLVA. The most important resistance phenotypes observed in this study was vancomycin-resistant phenotypes. Resistance to metronidazole was also high and highlights the need to determine its resistance mechanisms in the future studies.

Virulence determinants and biofilm formation of Acinetobacter baumannii isolated from hospitalized patients.

INTRODUCTION: Acinetobacter baumannii are nosocomial bacteria that are responsible for outbreaks and severe infections in hospitalized patients globally. The major target of this study was the characterization of virulence determinants and biofilm formation of A. baumannii isolates from hospitalized patients. METHODS: In total, 100 A. baumannii were collected from three hospitals in Tehran, Iran, 2017-2018. The isolates were assessed using phenotypic and genotypic methods and then screened for virulence factor encoding genes such as plcN and lasB using conventional polymerase chain reaction. Furthermore, bacterial biofilm formation, motility and hemolytic and proteolytic activities were assessed. RESULTS: Of 100 A. baumannii isolates, 20 isolates included plcN and four isolates included lasB using PCR assay. Overall, 21 isolates were negative for biofilm formation while 45, 20 and 14 of the total isolates were reported as weak, moderate and strong biofilm producers, respectively. All isolates were positive for bap genes using PCR. Moreover, 35 isolates were motile on Luria-Bertani media, 47 isolates were α-hemolytic on Brucella blood agar media and all isolates displayed proteolytic activity. CONCLUSIONS: Healthcare-associated infections with A. baumannii are a major concern, importantly due to their potency to acquire virulence factor genes. Therefore, shedding light in the discovery of new antimicrobial and/or therapeutic agents against virulent A. baumannii strains seem to be necessary.

Characterization of Clostridioides difficile isolates recovered from hospitalized patients and the hospitals environment and air: A multicenter study.

In healthcare settings, contamination of environment with toxigenic and hypervirulent Clostridioides difficile strains is a serious concern. Here, we assessed whether patients with C. difficile have a role to play in the dissemination of C. difficile in our settings or other sources are implicated in its circulation. A total of 700 fecal specimens and 1435 environmental samples from surfaces, equipment and air of rooms occupied by patients suspected of C. difficile infection were taken from 4 tertiary hospitals in Tehran, Iran between April 2016 and August 2017. Antibiotic susceptibility testing and detection of resistance genes were performed for the environmental isolates. The clinical and environmental isolates of C. difficile were subjected to Pulsed Field Gel Electrophoresis (PFGE) analysis. Forty three (6.14%) and 2 (0.13%) isolates of C. difficile were recovered from the clinical and environmental samples, respectively. In the clinical settings, 2 patients were suspected of recurrent C. difficile infection. Thirty distinct pulsotypes were found among the C. difficile isolates including 28 singletons and 2 common types. One of the two environmental isolates was isolated from floor in the Medical ward, of pulsotype/ribotype/toxinotype PT10/New ribotype/toxinotype V, harbored cdtA/B and tcdC-A, and resistant to ciprofloxacin. The other one was isolated from air of a room in ICU, assigned to PT11/RT001/toxinotype 0, belonged to tcdC-sc3 genotypes and resistant to metronidazole. The environmental isolates did not generate amplicons in PCR assays targeting vanA and nim genes. This study provided evidence for dissemination of genetically diverse strains of C. difficile in hospitalized patients, presence of C. difficile in hospital air, existence of binary toxin positive/antibiotic-resistant isolate on the floor and intra-hospital dissemination of this pathogen.

Bioinformatic prediction and experimental validation of a PE38-based recombinant immunotoxin targeting the Fn14 receptor in cancer cells.

AIM: AFn14R can serve as an ideal target for cancer immunotherapy. Here, a combined bioinformatic and experimental approach was applied to characterize an immunotoxin consisting of single-chain variable fragment antibody that targets Fn14 and a toxin fragment (PE38). METHODS & RESULTS: Flow cytometry results showed that the rate of PE38-P4A8 binding to Fn14 was approximately 60 and 40% in HT-29 and A549 cells, respectively. Moreover, 1 ng/µl of immunotoxin was able to lyse approximately 53 and 41% of HT-29 and A549, respectively. PE38-P4A8 showed stability in mouse serum (∼90%) after 3-h incubation. Most importantly, using bioinformatics for determining the structure and function of fusion proteins can be very helpful in designing of experiments. CONCLUSION: Coupled with bioinformatics, experimental approaches revealed that PE38-P4A8 could be used as a promising therapeutic agent for cancer cells expressing Fn14.

Carbapenem-resistant Acinetobacter baumannii (CRAB) Recovered from Burn Patients.

PURPOSE: Emergence of carbapenem-resistant Acinetobacter baumannii (CRAB) and their prolonged presence in burn units increases the risk of acquisition of CRAB. Methods. From November 2012 to September 2013, 1474 burn patients were screened for CRAB isolates through testing susceptibility to imipenem and its comparators meropenem, and doripenem. Furthermore, the in vitro activity of other antibiotics against CRAB was investigated.  Results. Three patients were infected with carbapenem-susceptible A. baumannii (CSAB) and 168 were infected with CRAB. Approximately one-fifth (n=32) of CRAB isolates were obtained from patients hospitalized in Burn Intensive Care Unit (BICU). Most of CRABs were isolated from wound. The mean length of stay (LOS) in hospital prior to A. baumannii isolation was significantly higher for CRAB compared to CSAB cases (P=0.04). Amongst the independent variables, percentage of total burn surface area (TBSA) significantly increased the mortality rate using multivariate logistic regression (P=0.001, OR= 16.5; 95% CI: 4.72-57.7). The majority of tested isolates were resistant to imipenem (94.8%), and to its comparators, doripenem (97.7%), and meropenem (97.7%). The susceptibility of CRAB isolates was less than 10% to all tested antibiotics except for colistin (100%), doxycycline (61.9%), gentamicin (18.5%), and tigecycline (11.9%). Conclusion. Resistance to carbapenem reduces the number of effective antibiotics. The coordinated and intensive efforts of healthcare personnel are required to meet the challenge of dissemination of CRAB.

Clonal relatedness and biofilm formation of OXA-23-producing carbapenem resistant Acinetobacter baumannii isolates from hospital environment.

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a serious threat for hospitalized patients and it can survive for long periods in hospital settings, particularly on inanimate surfaces. The environment occupied by these resistant and resilient isolates may act as a reservoir for cross-colonization and outbreaks. Here, we aimed to determine the distribution of CRAB in the hospital environment and to characterize their clonal relatedness, susceptibility profile, carriage of blaOXA genes, and biofilm formation. A total of 1080 samples were collected from various environmental surfaces and equipment of two referral hospitals in Tehran, Iran. The A. baumannii isolates were subjected to gyrB multiplex PCR, antibiotic susceptibility testing, biofilm formation assay, pulsed field gel electrophoresis (PFGE), and multiplex PCR for blaOXA-58, blaOXA-24, and blaOXA-23 genes. Eighteen Acinetobacter spp. were isolated; 8 were identified as A. baumannii and 10 as A. lwoffii. Five of A. baumannii isolates were CRAB and exhibited the multidrug-resistant (MDR) phenotype as well. All CRAB isolates produced biofilm, albeit with different levels. Four of CRAB isolates harbored the blaOXA-23. The CRAB isolates were clustered into 3 distinct pulsotypes (PTs). The CRAB isolates belonging to PT1 were detected in two geographically distinct hospitals whereas those belonging to PT3 were found in two different units of same hospital. This study revealed the presence of clonally related OXA-23-producing CRAB in high risk units of referral hospitals as inter- or intra-hospital dissemination. The distribution of multiresistant A. baumannii on several surfaces and areas may increase the risk of transmission of resistant isolates to vulnerable patients.

Detection of Clostridium difficile in Fecal Specimens: a Comparative Evaluation of Nucleic Acid Amplification Test and Toxigenic Culture.

BACKGROUND: The available data regarding Clostridium difficile infections (CDIs) in developing countries are scarce. This may be related in part to the complexity of anaerobic bacterial culture and/or cytotoxicity assays of C. difficile. Here, we evaluated the diagnostic efficacy of PCR in comparison with toxigenic culture for direct detection of conserved genes as well as toxin genes of C. difficile in fecal specimens of patients with clinical symptoms of CDI. METHODS: Loose or soft feces from 171 patients suspected of having C. difficile associated diarrhea (CDAD) were subjected to DNA extraction, PCR of cdu-2, cdd-3, gdh, tpi, tcdA/B, and toxigenic culture (TC). Limit of detection (LoD) was defined as the lowest concentration of DNA at which the target gene was amplified via PCR. The Kappa agreement between two diagnostic tests was calculated. RESULTS: The in-house extraction method extracted DNA successfully as confirmed by amplification of conserved genes of C. difficile. LoD of PCR for total DNA was 0.064 ng/µL. Only 10 specimens were positive for C. difficile via both PCR and TC. Among 10 identified C. difficile strains, 8 were tcdA+B+, but 2 were tcdA-B+. A very good agreement was observed between TC as reference method and PCR (κ = 1). CONCLUSIONS: Despite the high concordance between PCR and TC, this in-house nucleic acid amplification test can be used to identify symptomatic patients who harbor high amounts of bacteria. This procedure allows primary and same day diagnosis of C. difficile, and clinical laboratories in low-income countries may adopt the method for sample extraction and PCR assay at least for symptomatic patients.

Pulmonary nocardiosis associated with cerebral abscess successfully treated by co-trimoxazole: a case report.

Nocardiosis is an acute or chronic infectious disease caused by the soil-borne filamentous bacteria belonging to the genus Nocardia. The organisms opportunistically infect both immunocompromised and immunocompetent individuals. The lungs are the primary site of infection and brain abscess is, by far, the most common complication following nocardial metastasis from pulmonary lesions. Although surgical intervention must always be considered in the treatment of nocardial brain abscess, it can obviously be cured by antibiotic therapy alone. This report describes a case infected by Nocardia cyriacigeorgica. Identification of the infectious agent was achieved by conventional and semi-nested PCR techniques. A 55-year-old woman with fever was referred to the infect disclinic of Imam Khomeini hospital in Tehran and was hospitalized after clinical assessment. She was a kidney transplant recipient for 4 years and was taking immunosuppressive treatment including azathioprine and methylprednisolone. Follow-up of the patient by CT scan revealed pulmonary infection and cerebral lesions. Specimens of the brain lesions contained filamentous bacteria. The patient received a combination of co-trimoxazole and ceftriaxone and brain abscesses as well as lung inflammation disappeared gradually during the course of antibiotic therapy within 3 months. The patient was discharged from the hospital after 2 months of therapy.

Frequency of sabA Gene in Helicobacter pylori Strains Isolated From Patients in Tehran, Iran.

BACKGROUND: The importance of sialic acid binding adhesin (sabA) as a new outer membrane protein in gastroduodenal diseases has been recognized. The prevalence rate of sabA gene varies in different geographic areas. OBJECTIVES: The aim of this study was to determine the frequency of sabA gene in Helicobacter pylori (H. pylori) strains isolated from different clinical outcomes in Tehran, Iran. PATIENTS AND METHODS: The study included 120 patients with dyspeptic symptoms admitted to the endoscopy suite of gastroenterology section of Firouzgar University Hospital, Tehran, Iran from March to August 2011. Gastric biopsy specimens were evaluated for the presence of H. pylori using standard microbiological method and polymerase chain reaction (PCR) assay. The sabA genopositive was determined by PCR in H. pylori strains. RESULTS: H. pylori isolates were recovered from 82 patients with duodenal ulcer (DU; n = 17), gastric ulcer (GU; n = 15), gastric cancer (GC; n = 13), and gastritis (G; n = 37). The frequency of sabA gene in H. pylori strains was 100% in gastric cancer, 86.7% in gastric ulcer, and 83.3% in both gastritis and duodenal ulcer. CONCLUSIONS: This is a report on the prevalence of sabA gene in H. pylori isolated from different gastric patients in Iran. The results showed a high prevalence of sabA in our clinical H. pylori isolates.