Association between colorectal cancer, the frequency of Bacteroides fragilis, and the level of mismatch repair genes expression in the biopsy samples of Iranian patients

BACKGROUND

Deficient DNA mismatch repair (MMR) can cause microsatellite instability (MSI) and is more common in colorectal cancer (CRC) patients. Understanding the carcinogenic mechanism of bacteria and their impact on cancer cells is crucial. Bacteroides fragilis (B. fragilis) has been identified as a potential promoter of tumorigenesis through the alteration of signaling pathways. This study aims to assess the expression levels of msh2, msh6, mlh1, and the relative frequency of B. fragilis in biopsy samples from CRC patients.

MATERIALS AND METHODS

Based on the sequence of mlh1, msh2, and msh6 genes, B. fragilis specific 16srRNA and bacterial universal 16srRNA specific primers were selected, and the expression levels of the target genes were analyzed using the Real-Time PCR method.

RESULTS

Significant increases in the expression levels of mlh1, msh2, and msh6 genes were observed in the cancer group. Additionally, the expression of these MMR genes showed a significant elevation in samples positive for B. fragilis presence. The relative frequency of B. fragilis in the cancer group demonstrated a significant rise compared to the control group.

CONCLUSION

The findings suggest a potential correlation between the abundance of B. fragilis and alterations in the expression of MMR genes. Since these genes can play a role in modifying colon cancer, investigating microbial characteristics and gene expression changes in CRC could offer a viable solution for CRC diagnosis.

Comparative evaluation of real-time PCR and ELISA for the detection of human fascioliasis

Fascioliasis is a zoonotic parasitic infection caused by Fasciola species in humans and animals. Despite significant advances in vaccination and new therapeutic agents, little attention has been paid to validating methods for the diagnosis of fascioliasis in humans. Serological techniques are convenient assays that significantly improves the diagnosis of Fasciola infection. However, a more sensitive method is required. The aim of this study was to compare the Real-Time PCR technique with the indirect-ELISA for the detection of Fasciola hepatica in human. Using a panel of sera from patients infected with Fasciola hepatica (n = 51), other parasitic infections (n = 7), and uninfected controls (n = 12), we optimized an ELISA which employs an excretory-secretory antigens from F. hepatica for the detection of human fascioliasis. After DNA extraction from the samples, molecular analysis was done using Real-Time PCR technique based on the Fasciola ribosomal ITS1 sequence. Of 70 patient serum samples, 44 (62.86%) samples were identified as positive F. hepatica infection using ELISA and Real-Time PCR assays. There was no cross-reaction with other parasitic diseases such as toxoplasmosis, leishmaniasis, taeniasis, hydatidosis, trichinosis, toxocariasis, and strongyloidiasis. The significant difference between the agreement and similarity of the results of patients with indirect ELISA and Real-Time PCR was 94.4% and 99.2%, respectively (Cohen's kappa ≥ 0.7; P = 0.02). Based on the Kappa agreement findings, the significant agreement between the results of ELISA and Real-Time PCR indicates the accuracy and reliability of these tests in the diagnosis of F. hepatica in humans.

Characterization of class 1 integrons in metallo-β-lactamase-producing Acinetobacter baumannii isolates from hospital environment

BACKGROUND AND OBJECTIVE

The emergence and widespread dissemination of antibiotic resistance in A. baumannii, has become a globally challenge. The increasing hospital outbreaks by multi-drug resistant (MDR) A. baumannii strains, shows the necessity of continuous monitoring to find sources of resistant strains in hospitals. This study aimed to identify the presence of class 1 integrons and metallo-β-lactamase (MBL) related genes in A. baumannii isolates from hospital environment.

METHODS

In order to identify A. baumannii isolates, a total of 297 environmental samples were collected from burn wards and intensive care units (ICUs) of two university hospitals. Resistance to common antibiotics was studied by disk diffusion method and microbroth dilution assay was used to determine the minimum inhibitory concentrations (MICs) of imipenem, colistin and tigecycline. The A. baumannii isolates were studied by polymerase chain reaction (PCR) for the presence of class 1 integrons (intI1, intl CS) and metallo-β-lactamases (MBLs) (blaIMP, blaVIM, blaNDM) genes.

RESULTS

A. baumannii was identified in 68/297 (22.9%) of hospital environment. All A. baumannii strains were multidrug-resistant (MDR), but none of them were resistant to colistin, tigecycline and ampicillin-sulbactam. All (100%) and 38 (95.0%) of A. baumannii isolates from ICUs and burn wards were imipenem resistant respectively. Class 1 integrons was identified in 30/40 (75.0%) and 23/28 (82.1%) isolates from burn wards and ICUs respectively. Two different types of gene cassettes were identified, which included: arr-2, ereC, aadA1, cmlA5 and arr2, cmlA5. MBL genes including blaVIM and blaIMP were detected in 26/28 (92.8%), 27/28(96.4%) and 39/40 (97.5%) and 31/40 (77.5%) of the isolates from the ICUs and the burn wards respectively. None of the isolates contained the blaNDM-1 gene.

CONCLUSION

The findings of the present study showed that the isolation rate of MBL producing carbapenem-resistant A. baumannii (CRAB) was relatively high in the environmental surface of burn wards and ICUs, which can be considered as a potential source of outbreaks in hospitalized patients.

Clonal relatedness of carbapenem-resistant Acinetobacter baumannii: high prevalence of ST136pas in a burn center

BACKGROUND

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a global health crisis. This study aimed to determine the clonal relatedness of antibiotic-resistant A. baumannii isolates in hospitalized patients who suffered from burn wound infection.

METHODS

One hundred and six A. baumannii isolates from 562 patients with burn wound infections, were identified and examined for antimicrobial susceptibility. Detection and characterization of carbapenem-hydrolyzing class D OXA-type beta-lactamases (CHDLs) were performed by PCR assays. The clonal relatedness of A. baumannii isolates was determined by multilocus sequence typing (MLST) according to the Pasteur scheme, dual-sequence typing of bla_OXA-51-like and ampC genes, and RAPD-PCR method.

RESULTS

All isolates were carbapenem-resistant while susceptible to colistin, minocycline, doxycycline, and ampicillin-sulbactam. The intrinsic bla_OXA-51-like was detected in all isolates, and bla_OXA-23-like was identified in 92.5% of isolates. However, bla_OXA-143-like and bla_OXA-58-like genes were not detected among isolates. Four distinct bla_OXA-51-like alleles were determined as follows: bla_OXA-317 (67.0%), bla_OXA-90 (9.4%), bla_OXA-69 (17.0%), and bla_OXA-64 (6.6%) and four ampC (bla_ADC) allele types including ampC-25 (6.6%), ampC-39 (9.4%), ampC-1 (17.0%), and bla_ADC-88 (67.0%) were identified. MLST (Pasteur scheme) analysis revealed four ST types including ST136 (singleton), ST1 (CC1), ST25 (CC25), and ST78 (singleton) in 71, 18, 7, and 10 of A. baumannii strains, respectively. Five RAPD clusters including A (1.9%), B (26.4%), C (57.5%), D (7.5%), and E (1.9%) were characterized and 5 (4.7%) strains were found to be singletons.

CONCLUSION

The present study demonstrated that there was a high prevalence of bla_OXA-23-like producing CRAB in the clinical setting. The majority of isolates belonged to ST136 (singleton). However, bla_OXA-23-like producing multi-drug resistant international clones including ST1, and emerging lineages (e.g. ST25 and ST78) were also identified. Interestingly, in this study ST2 was not detected.

Molecular investigation of Toxocara infection from the serum of people living with HIV in Alborz, Iran

BACKGROUND

Toxocara infection is one of the most common neglected infections of poverty and a helminthiasis of global importance. Traditional diagnostic methods such as antibodies detection in serum samples are limited due to cross-reactivity and poor sensitivity. The use of molecular base methods for diagnosis of Toxocara infection in Iran has not been fully explored. The purpose of the current study was to estimate the prevalence of Toxocara infection from serum samples of people living with HIV in Alborz province, Iran using serological and molecular methods.

METHODS

Blood samples were collected from 105 people living with HIV. Epidemiological data of participant were obtained through a structured questionnaire to investigate the risk factors. Patients CD4⁺ T cell count were recorded. Anti-Toxocara IgG antibodies were detected by ELISA, with a cut-off point of 11. PCR was performed to detect genetic material of Toxocara species in the serum samples.

RESULTS

The mean CD4⁺ count in HIV-infected individuals with positive toxocariasis serology was 255.1 ± 21.6 cells/µL. Seropositivity for Toxocara species was observed in 12/105 (11.4%) people living with HIV. Three samples gave positive results on PCR analysis. Based on the data, a statistically significant relationship was found between anti-Toxocara IgG antibodies seropositivity and underlying conditions (p = 0.017). No significant statistical association was observed between seropositivity for Toxocara and gender, age, exposure to domestic animals or pet keeping, education levels, and occupation (p > 0.05). The findings of PCR confirmed Toxocara DNA in 3/12 (25.0%) serum samples.

CONCLUSION

These findings demonstrated for the first time that people living with HIV from Alborz province, are being exposed to this zoonosis and a relatively high seroprevalence of Toxocara in HIV/AIDS people needs comprehensive health education regarding personal hygiene and how to avoid exposure to this parasite infection, especially in people with an impaired immune system.

Detection of multidrug-resistant Acinetobacter baumannii from burn patients and healthcare workers in Iran

Multidrug-resistant (MDR) Acinetobacter baumannii is a serious global health threat. Burn patients are at high risk to acquire A. baumannii infections from endogenous sources. This study evaluated carbapenem resistance and clonal relatedness of A. baumannii isolated from burn patients and healthcare workers (HCWs).The study was performed in 100 non-duplicated A. baumannii isolates from nasal and hand samples of hospitalized burn patients and HCWs in two hospitals of Iran from June 2020 to August 2021. Antimicrobial susceptibility testing was performed and carbapenemase genes were detected by PCR. Clonal relatedness of A. baumannii isolates was determined by two single-locus sequence-based typing of blaOXA-51-like and ampC and by multilocus sequence typing (MLST).All A. baumannii isolates were found to be MDR while susceptible to colistin. The intI1, conserved segments of class 1 integron (intI1 CS), blaIMP, blaVIM, blaOXA-51-like, and blaOXA-23-like, genes were detected in 32.5%, 29.1%, 36%, 95.3%, 100%, 100%; and 14.3%, 14.3%, 21.4%, 92.9%, 100%, and 85.7% of isolates from patients and from healthcare workers, respectively. The blaOXA-58, and blaOXA-143 were not detected among the isolates. Using dual-locus blaOXA-51-like and ampC sequence-based typing (SBT), the isolates obtained from nasal samples of burn patients were grouped into 3 clusters including blaOXA-317, blaADC-88 (72.1%); blaOXA-64, ampC-25 (18.6%); and blaOXA-69, ampC-1 (9.3%). While only allele type blaOXA-317, blaADC-88 was determined among isolates from HCWs. MLST results showed A. baumannii ST136, ST25, and ST1 from burn patients. However, A. baumannii strains from HCWs belonged to ST136. Our findings indicate high prevalence of globally spreading of MDR A. baumannii ST136 carrying blaOXA-23-like from nasal and hand samples of burn patients and HCWs.

Intestinal parasites and diabetes: A systematic review and meta-analysis

Background

Investigating the association between infectious agents and non-communicable diseases is an interesting emerging field of research. Intestinal parasites (IPs) are one of the causes of gastrointestinal complications, malnutrition, growth retardation and disturbances in host metabolism, which can play a potential role in metabolic diseases such as diabetes. The aim of the present study was to investigate the prevalence of IPs in diabetic patients and the association between IPs and diabetes.

Methods

A systematic literature search was conducted from January 2000 to November 2022in published records by using PubMed, Scopus, and Web of Science databases as well as Google scholar search engine; Out of a total of 29 included studies, fourteen cross-sectional studies (2676 diabetic subjects) and 15 case-control studies (5478 diabetic/non-diabetic subjects) were reviewed. The pooled prevalence of IPs in diabetics and the Odds Ratio (OR) were evaluated by CMA V2.

Results

In the current systematic review and meta-analysis, the pooled prevalence of IPs in diabetic patients was 26.5% (95% CI: 21.8-31.7%) with heterogeneity of I² = 93.24%; P < 0.001. The highest prevalence based on geographical area was in Region of the Americas (13.3% (95% CI: 9.6-18.0)).There was significant association between the prevalence of intestinal parasites in diabetic cases compared to controls (OR, 1.72; 95% CI: 1.06-2.78).

Conclusion

In line with the high prevalence of IPs in diabetic patients, significant association was found however, due to the limitations of the study, more studies should be conducted in developing countries and, the prevalence of IPs in diabetics should not be neglected.

Reverse vaccinology approach to identify novel and immunogenic targets against Porphyromonas gingivalis: An in silico study

Porphyromonas gingivalis is a primary causative agent of chronic periodontitis. Moreover, it leads to several systemic diseases, including rheumatoid arthritis, cardiovascular, neurodegenerative, and Alzheimer’s diseases. It seems that the development of a vaccine against this bacterium is necessary. Thus, this study decided to identify novel immunogenic targets and developed multiple epitope-based vaccines against P. gingivalis. For this purpose, the pan/core-proteome of this bacterium was studied, and the suitable vaccine targets were selected based on different properties, including exposed localization of proteins, antigenicity, non-allergenicity, non-similarity to host proteome, stability, B-cell epitopes and MHC II binding sites, sequence conservation, molecular docking, and immune simulation. Through the quartile scoring method, 12 proteins with ≥ 20 scores were considered as suitable immunogenic targets. The results of the protein domain and functional class search showed that most of the immunogenic proteins were involved in the transport and metabolism of inorganic ions and lipids. In addition, two unknown function proteins, including WP_004584259.1 and WP_099780539.1 were detected as immunogenic targets. Three constructions carrying multi-epitopes were generated including Naked, LCL, and as chimeric structures. Among them, FliC chimeric protein had the strongest affinity to the human TLR2, 4, and 6, while the LCL platform represented the highest level of immune stimulation response. The obtained results from this study revealed new insights into prophylactic routes against P. gingivalis by introducing novel immunogenic targets. However, further investigations, including site-directed mutation and immunoassay are needed to confirm the pathogenic role and protectivity of these novel proteins.

Molecular Detection of OXA-type Carbapenemases among Acinetobacter baumannii Isolated from Burn Patients and Hospital Environments

Background:

Acinetobacter baumannii is known as one of the major causes of nosocomial infections, especially in intensive care units and burn patients. The emergence of antimicrobial resistance in burn wound bacterial pathogens is a severe health crisis. Detection of carbapenem resistance and genetic elements in A. baumannii associated with burn patients and hospital environments play a key role in the control and alerting in clinical settings.

Purpose:

In this study, the prevalence of OXA-type carbapenemases was investigated in A. baumannii strains isolated from burn patients and from a hospital environment in Tehran, 2021.

Methods:

A total of 85 non-duplicate A. baumannii isolates (53 from various surfaces of the hospital environment and 32 from burn patients) were recovered in the Burns Hospital in Tehran. The A. baumannii isolates were screened for antibiotic susceptibility and the presence of the most common OXA-type carbapenemase genes.

Results:

A. baumannii was isolated from 38.5% of hospital patient burn wounds and 22.1% of surfaces, including burn units (15.6%) and intensive care units (52.4%). Antibiotic susceptibility results showed that (100%) of burn patient isolates were resistant to imipenem, while (100%) of ICU isolates and (96.8%) of burn isolates were resistant to imipenem. All clinical isolates were identified as MDR and XDR, whereas all (100%) and 98.1% of environmental isolates were identified as MDR and XDR, respectively. All studied A. baumannii isolates carried blaOXA-51-like gene. Moreover, 50 (94.3%) and 49 (92.5%) of environmental isolates, 32 (100%) and 30 (93.7%) of burn patient isolate harbored blaOXA-23-like and blaOXA-24/40–like genes, respectively. None of the isolates carried the blaOXA-58 or blaOXA-143 genes and all isolates had at least 2 OXA-type carbapenemase genes.

Conclusion:

Our results suggest that surfaces in the hospital environment, particularly in ICUs, are contaminated with MDR or XDR A. baumannii strains. They may be considered a potential reservoir for the colonization of hospital patients. In addition, OXA-type carbapenemases, including OXA-23-like and OXA-24/40-like, appear to be one of the major mechanisms of carbapenem resistance in the clinical and environmental A. baumannii strains.

Larva migrans in BALB/c mice experimentally infected with Toxocara cati ensured by PCR assay

BACKGROUND

Toxocara cati, the cat roundworm, is a parasitic nematode that known to cause toxocariasis in intermediate hosts and humans. In this study, we characterized the dynamics of T. cati larvae migration in BALB/c mice after inoculation with eggs and ensured the migration detecting the larval DNA by a PCR. To evaluate the dynamics of larval migration and distribution, twenty-four BALB/c mice were orally inoculated with 2500 T. cati infective eggs and the visceral organs of the infected animals were examined by pepsin digestion and microscopic parasite counts, followed by PCR at day 1 to 28 post-inoculation.

RESULTS

The PCR assays were successfully used for detection of T. cati larvae in tissue samples and T. cati larvae and the DNAs were found in the liver, lungs, heart, kidneys and the brain. We detected T. cati in 92.2% of tissue samples by PCR, 30% higher than the conventional pepsin digestion technique.

CONCLUSION

Our findings demonstrated that the PCR assay is a sensitive and specific for the detection of T. cati larvae. Therefore, it could become a useful tool for the investigation of the dynamics of larval migration and Toxocara infection in murine model.

Ocular Toxocariasis Associated with Blurred Vision and Visual Impairment: Report of Four Cases

Ocular toxocariasis in humans is caused by infection with larvae of Toxocara species, which are common ascarid roundworms of mammals, kept in close proximity to human. Four cases with a history of contact with dogs and cats and blurred vision and visual impairment over periods of variable duration were examined. We screened patients diagnosed with ocular larva migrans syndrome between March and June 2021 at the Ophthalmology clinics affiliated with Alborz University of Medical Sciences, Karaj, Iran. Detailed demographics, clinical characteristics, and fundus photography were recorded. Anti-Toxocara antibodies in the sera and vitreous fluid detected by ELIZA. Complete recovery in all four patients was achieved following treatment with oral albendazole. The diagnosis of ocular toxocariasis can be challenging, because both the condition is relatively uncommon and its presentation varies from patient to patient. There are lots of differential diagnoses like retinoblastoma, therefore correct, quick diagnosis, and treatment is very important.

Serosurvey of anti-Toxocara antibodies and associated risk factors in domestic dogs and cats owners in Karaj, Alborz Province of Iran

INTRODUCTION AND OBJECTIVE

Toxocariasis is a zoonotic parasitic infection with important public health considerations. The aim of the study was to assess the prevalence of anti-Toxocara species antibodies and associated risk factors in domestic dogs and cats referred by their owners to veterinary clinics located in Karaj, Alborz Province, Iran.

MATERIAL AND METHODS

A cross-sectional study involving 540 owners of dogs and cats was conducted between July - December 2020. A questionnaire administered by direct interviews was used to collect socio-demographic information and data on associated risk factors. Blood samples were collected and tested by indirect enzyme-linked immunosorbent assay (ELISA).

RESULTS

The overall sero-prevalence of toxocariasis among the 540 participants was 16.7% (90 of 540). When participants included in the sample were classified by age, those aged 10-29 years demonstrated higher Toxocara infection prevalence than other groups (45.6%, 41 of 90). Univariate analysis revealed that the pet owners who had contact with soil [adjusted odds ratio (AOR) = 7.61, 95% CI: 6.06-9.24, P = 0.028], practiced handwashing after contact with dogs and cats (AOR = 2.42, 95% CI: 1.15-4.85, P = 0.046), and feeding the pets with raw meat (AOR = 11.01, 95% CI: 5.21-19.43, P = 0.023) had an increased risk of acquiring toxocariasis. The study showed that demographic characteristics such as age, gender, place of residence, education, and pet's habitats were not significantly associated with toxocariasis.

CONCLUSIONS

Given the findings and the progressive impact of toxocariasis in public health and its high prevalence in developing countries, including Iran, measures should be taken to inform the public about zoonoses and eliminate their putative transmission.

High prevalence of clonally related multiple resistant Salmonella Infantis carrying class 1 integrons in broiler farms

The poultry industry in Iran is the main supplier of protein in the food chain. In the present study, we showed the importance of the possible dissemination of clonally related multiple drug resistant (MDR) Salmonella Infantis in broiler farms in Iran. In total, 156 fecal samples belonging to 23 poultry farms in Razavi Khorasan province, northeast of Iran, were examined for the presence of Salmonella serovars. Molecular serotypes and serogroups, class 1 and 2 integron types, colistin resistance genes ( mcr1 and mcr2) and antimicrobial susceptibility patterns were determined on the recovered Salmonella isolates. Based on PCR analysis, 30 recovered Salmonella isolates were identified asS. Infantis (23 isolates; 76.6%),S. Enteritidis (six isolates; 20%), and one isolate (3.3%) was not serotyped by the applied method. Class 1 integrons were detected in 22 isolates (95.6%) and class 2 integrons were not detected in any of the isolates. Although colistin resistance was prevalent in disc diffusion test, mcr-1 and mcr-2 genes were not detected. All class 1 integrons carried the cassette aadA1 gene. All Salmonella isolates were resistant to colistin and amoxicillin/clavulanic acid and MDR patterns were observed in most (96.6%) isolates. This study revealed a high prevalence rate of S. Infantis and the presence of class 1 integrons in broiler farms. The presence of the same integron cassettes in the sequenced isolates suggests that strains are clonally related. Stringent monitoring programs are required to prevent the spreading of MDR Salmonella serovars into food chain via poultry products.

Toxocara Species Infection in Pet Dogs and Cats Ensured by Loop-Mediated Isothermal Amplification Assay

Background: Toxocariasis is a parasitic disease with global distribution. Many paratenic or transport hosts have been identified as the sources of infection, including vertebrates such as birds and humans. The definitive hosts of Toxocara are dogs and cats whose parasites live in their guts. Hence, the diagnosis of the disease in these animals is important. Objective: The present study was performed using the loop-mediated isothermal amplification (LAMP) method to diagnose toxocariasis. Materials and Methods: In the present study, 60 samples of pet feces were collected and subsequently evaluated by direct smear, formalin-ether, and LAMP. Results: Toxocara infection in dogs by microscopic and formal ether methods and LAMP method was 10% and 13.3%, respectively, while feline infection with this parasite was not observed either microscopically or molecularly. Conclusion: The present findings revealed that pet dogs can be considered as a source of infection for humans. Therefore, it is recommended that animal owners receive the necessary training to prevent the risks of transmitting zoonotic diseases.

Molecular study of metallo-β-lactamases and integrons in Acinetobacter baumannii isolates from burn patients

BACKGROUND

Productions of metallo-β-lactamases enzymes are the most common mechanism of antibiotic resistance to all beta-lactam classes (except monobactams) in Acinetobacter baumannii. MBLs are usually associated with gene cassettes of integrons and spread easily among bacteria. The current study was performed to detect the genes encoding MBLs and integron structures in A. baumannii isolates from burn patients.

METHODS

This study was performed on 106 non-duplicate A. baumannii isolates from burn patients referred to Shahid Motahari Hospital in Tehran. Antibiotic susceptibility of A. baumannii isolates was performed using disk diffusion and broth microdilution method in accordance with the CLSI guidelines. The presence of class 1 integron and associated gene cassettes as well as MBLs-encoding genes including bla_VIM, and bla_IMP were investigated using PCR and sequencing techniques.

RESULTS

In this cross-sectional study all (100%) of the A. baumannii isolates examined were multidrug resistant. All isolates were sensitive to colistin and simultaneously all were resistant to imipenem. PCR assays showed the presence of bla_VIM and bla_IMP genes in 102 (96.2%) and 62 (58.5%) isolates of A. baumannii respectively. In addition, 62 (58.5%) of the A. baumannii isolates carried integron class 1, of which 49 (79.0%) were identified with at least one gene cassette. Three types of integron class 1 gene cassettes were identified including: arr2, cmlA5, qacE1 (2300 bp); arr-2, ereC, aadA1, cmlA7, qacE1 (4800 bp); and aac(3)-Ic, cmlA5 (2250 bp).

CONCLUSION

A high prevalence of MBLs genes, especially bla_VIM, was identified in the studied MDR A. baumannii isolates. In addition, most of the strains carried class 1 integrons. Furthermore, the gene cassettes arrays of integrons including cmlA5 and cmlA7 were detected, for the first time, in A. baumannii strains in Iran.

The combination of CipA and PBP-7/8 proteins contribute to the survival of C57BL/6 mice from sepsis of Acinetobacter baumannii

Due to the emergence of multi-drug resistant Acinetobacter baumannii strains, there is an urgent need to develop several new strategies to control this bacterium. In this context, vaccination may be the best approach to reduce the morbidity and mortality associated with MDR isolates in vulnerable groups. Serum resistance factors have a key role in the pathogenesis of A. baumannii and can be considered as potential vaccine candidates. This project aimed to evaluate the immunological reactivity of CipA and PBP-7/8 as two serum resistance factors in a combination form against sepsis infections of A. baumannii. Recombinant proteins were obtained and immunological evaluations were performed against sepsis infection in the C57BL/6 mouse model. The data showed a statistically significant increase in total IgG levels in all three immunization regimens (CipA, PBP-7/8, and CipA + PBP-7/8) compared to the control group. The ratios of IgG2c/IgG1 in the CipA, PBP-7/8, and CipA + PBP-7/8 schedules were 8.7, 46.50, and 33.29, respectively. It appears that the immunization schedules developed a strong polarized Th1 response. The cytokine profiles of the three plans showed that IFN-γ was highly concentrated in the combination plan. However, the highest concentration of IL-17 belonged to the PBP-7/8 plan. In conclusion, the data of total IgG, survival rates and splenic bacterial loads showed that the CipA + PBP-7/8 plan was more effective than each protein individually.

Molecular analysis of methicillin-resistant Staphylococcus aureus isolates from four teaching hospitals in Iran: the emergence of novel MRSA clones

Background

The global spread of methicillin-resistant Staphylococcus aureus (MRSA) infections necessitates the use of validated methods for the identification and typing of this bacterium. This study aimed to determine the distribution of main molecular types of MRSA strain circulating among hospitalized patients in teaching hospitals in Isfahan and Kashan.

Methods

A total of 146 Staphylococcus aureus strains were isolated from patients in four teaching hospitals in Isfahan and Kashan during June 2017 to September 2018. The antimicrobial resistance patterns of Staphylococcus aureus strains were performed by disc diffusion method. The MRSA strains were identified phenotypically and confirmed by PCR assay. The prevalence of microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) genes among MRSA strains was evaluated by multiplex PCR. The genotypes of MRSA strains were determined by multilocus sequence typing and SCCmec typing.

Results

Of 146 Staphylococcus aureus isolates, 24 (16.4%) isolates were identified as MRSA strains. According to antimicrobial susceptibility testing the highest resistance rates were seen for tetracycline, erythromycin, ciprofloxacin and gentamicin. All of Staphylococcus aureus isolates were susceptible to vancomycin whereas 3 (2.1%) isolates were resistant to linezolid. Three different SCCmec types were obtained among MRSA strains including 16 (66.7%) SCCmec type V, 3 (12.5%) SCCmec type III and 5 (20.8%) SCCmec type II. Of 24 MRSA isolates 20 (83.3%) carried MSCRAMMs genes including eno (70.8%), fib (54.1%), cna (25.0%), fnbB (16.6%), ebps 5 (20.8%), and the fnbA, bbp and clfA genes were not detected in any MRSA isolate. MLST analysis revealed 11 sequence types among MRSA isolates as follows: ST239, ST291, ST22, ST861, ST889, ST8, ST59, ST343, ST772, ST6 and ST1465. Also seven MLST-based clonal complexes (CCs) were identified among MRSA strains including: CC8, CC7, CC398, CC59, CC22, CC1 and CC5.

Conclusions

A relatively high diversity was found in MRSA genotypes in Kashan and Isfahan hospitals, and seven clonal complexes were identified. Pandemic MRSA clones including CC8 and CC22 were the most prevalent clones and the novel ST types including ST1465, ST861, ST 889 and ST772 are reported for the first time in Iran in the present study. In addition the high prevalence of MSCRAMMs genes in MRSA isolates demonstrates the high potential of these strains for pathogenicity.

Evaluation of Genomic DNA Extraction Using Monolayer and Bilayer Magnetic Nanoparticles

Background: There are different methods for genomic DNA extraction. Magnetic nanoparticles (MNPs) exhibit many important features making them suitable for DNA extraction. Objectives: The aim of this study was to compare the effect of monolayer and bilayer MNPs on genomic DNA extraction. Materials and Methods: The genomic DNA was extracted from the Staphylococcus aureus strain ATCC 25923 and clinical isolates using monolayer MNPs SiO2 and Fe3O4 and bilayer MNPs SiO2/Fe3O4. Then, the quality and quantity of the obtained genomic DNA were compared with both NPs. Results: The obtained results showed the concentration and purity of the extracted genomic DNA using bilayer magnetic NPs was significantly higher in comparison to the extracted genomic DNA by monolayer MNPs. Conclusion: In general, surface-coated MNPs are much more efficient than naked MNPs for genomic DNA extraction.

Environmental soil contamination by Toxocara species eggs in public places of Ilam, Iran

INTRODUCTION

The purpose of the study is to assess environmental contamination by Toxocara species eggs in public places in the city of Ilam, Ilam Province, southwest Iran.

MATERIAL AND METHODS

Between September 2018 and March 2019, 130 soil samples were collected from public places of 5 district municipalities of Ilam, southwest Iran. Soil samples were examined by microscopy following flotation method by sodium nitrate.

RESULTS

Soil analysis showed that 5.88% of the soils stored, 52.54% from gardens, 29.42% from rubbish, and 11.72% from green spaces were contaminated with Toxocara spp. eggs. In total, 13.08 % of soil samples (17/130) were positive for Toxocara eggs (P > 0.05).

CONCLUSIONS

The findings revealed that care should be taken when using soil from gardens, green spaces and rubbish, and also should be seriously considered because of the potential issues of toxocariasis and also the risk to the public.

Ability of biofilm production and molecular analysis of spa and ica genes among clinical isolates of methicillin-resistant Staphylococcus aureus

Objective

This study aimed to evaluate the phenotypic and genotypic characterization of biofilm formation and spa and ica genes among clinical isolates of methicillin-resistant Staphylococcus aureus.

Result

This cross-sectional study was performed on 146 Staphylococcus aureus isolates from hospitalized patients in Isfahan Province Hospitals. MRSA isolates were confirmed using disk diffusion test with oxacillin disk and amplification of mecA gene by PCR assays. Ability of biofilm production was evaluated targeting the icaA and icaD genes. Of 146 Staphylococcus aureus isolates, 24 (16.4%) carried mecA genes and identified as MRSA strains. Strong ability of biofilm production was seen among 76.02% (111/146) S. aureus isolates and 87.5% (21/24) MRSA strains, respectively. Also, 75.0% (18/24) MRSA isolates carried icaA and icaD was not detected in these strains. Analysis of spa gene showed 70.83% (17/24) MRSA strains were spa positive. From which 14 and 3 strains identified with one band (150, 270, 300, 360, 400 bp) and two bands (150–300 bp), respectively. According to data obtained, the prevalence of MRSA isolates from Isfahan Province Hospitals is relatively high and a remarkable percentage of them show strong power in biofilm production. Also analysis of spa gene showed a fairly large diversity among MRSA strains.

Parasitological and molecular study of Toxocara spp. in Lumbericus terrestricus earthworms

Soil-associated invertebrates which are coprophagic are capable of acting as paratenic hosts for Toxocara species larvae eggs. The aim of the present study was to assess the role of Lumbricus terrestris earthworms as potential intermediate host for Toxocara species. A total of 240 earthworms were collected from the public places in four areas of Karaj, Alborz Province, Iran. The subjects of the study were digested to detect Toxocara species using microscopy and molecular analyses. Toxocara larvae and larval eggs were recovered from 1.7% (4/240) of the sampled earthworms. The recovery rate in Shah'Abbasi and Talaghani regions in the studied areas was higher than that of the other regions. In the mentioned area, 8.3% (4/48) of earthworms were revealed to be positive for Toxocara species by microscopic observation and only one was confirmed to be positive for Toxocara canis by polymerase chain reaction (PCR). This is the first molecular report of Toxocara canis infective larvae in Lumbricus terrestris earthworms that could be demonstrated in common environment.

Construction, Cloning, and Expression of CagA Recombinant Protein of Helicobacter pylori

BACKGROUND

This study aimed to assess construction and expression of CagA recombinant protein of Helicobacter pylori (H. pylori) in Escherichia coli (E. coli) BL21.

METHODS

Bioinformatics was used in designing the desired gene by Gene Runner. Next, the construct was subcloned to pET21b vector and this process was confirmed by Polymerase Chain Reaction (PCR), enzyme digestion and sequencing techniques. Then, it was cloned in the Escherichia coli BL21 as an expression host. Expression of protein was verified using sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting technique. For purification of the protein, the Ni-NTA column was used. Protein concentration was determined by the Bicinchoninic Acid Protein Assay Kit (Parstoos). Finally, Western blotting was performed using CagA antibodies and normal human serum for determining immunogenicity feature with human antiserum.

RESULTS

According to the results of the present study, CagA construct was cloned into the pET21b vector and after confirmation and cloning in host expression, recombinant protein with the size of 38 kDa was successfully expressed and purified. The recombinant CagA protein showed immunogenicity characteristics with human antiserum.

CONCLUSION

In conclusion, only 5'-end of recombinant protein CagA with high immunogenicity effects was successfully constructed, cloned and expressed. Also, CagA recombinant protein showed good immunogenicity activity with human antiserum.

Rapid Detection of Pathogenic Bacteria in Whole Blood Samples Using 23S rRNA PCR Assays

Purpose:

Bloodstream infections are a general cause of death among hospitalized patients. Rapid diagnosis and timely treatment can reduce mortality. The aim of this investigation was to evaluate the 23S rRNA PCR assays as a rapid detection method for diagnose of sepsis in patients with suspected bacteremia.

Methods:

A cross-sectional study was conducted at Shahid Beheshti University Hospital in Kashan from November 2017 to December 2018. The blood samples of 265 patients with suspected bacteremia were studied by blood culture and 23S rRNA PCR techniques. The results were analyzed using SPSS version 16 and Chi-square test.

Results:

Eighty (30.2%) blood samples of 265 suspected patients, were identified as positive by PCR assays, whereas 27 (10.2%) were identified as positive by the blood culture technique. The statistical analysis showed a significant association between the results of PCR assays and blood culture and factors such as prior antibiotic use and underlying diseases (P˂0.05). Also a significant correlation was observed between laboratory and clinical criteria and the results of both PCR assays and blood culture (P˂ 0.05).

Conclusion:

The 23S rRNA PCR method is a rapid and sensitive technique specially for diagnosing sepsis among patients in whom bacteremia is difficult to diagnose with culture method including neonates and patients who have taken antibiotics before microbial culture.

Molecular characterization of class 1, 2 and 3 integrons in clinical multi-drug resistant Klebsiella pneumoniae isolates

Background

The aim of this study was to characterize class 1,2 and 3 integrons in clinical MDR Klebsiella pneumoniae isolates in Kashan, Iran.

Methods

One hundred-eighty one Klebsiella pneumoniae were recovered from clinical specimens during November 2013 to October 2014. Antimicrobial susceptibility patterns were determined by disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines for detection of MDR strains. Of the 181 Klebsiella pneumoniae, 146 (80.7%) of isolates were isolated from nosocomial infected patients and 150 (82.9%) identified as MDR isolates. The PCR amplification was used to show presence of class 1, 2 and 3 integrons among MDR strains. The PCR method and sequencing were used for evaluation of cassette content of integrons.

Results

Of the MDR K. pneumoniae isolates, 150 (100%) and 55 (36.7%) carried intI1 and intI2 genes, respectively. None of the MDR Klebsiella pneumoniae isolates carried class 3 integrons. Amplification of conserved segment (CS) of class 1 and class 2 integrons revealed 10 different arrays including: No. cassette; dfrA5, dfrA30; aadA2; aadA2, dfrA12; dfrA17, aadA5, aadA4; dfrA5, dfrA30, aadA2; dfrA5, dfrA30, aadA2, dfrA12, dfrA5, dfrA30, dfrA17, aadA5, aadA4; aadA2, aadA2, dfrA12; dfrA5, dfrA30, aadA2, aadA2, dfrA12 and 4 arrays including: No. cassette; aadA1; dfrA1-sat1; aadA1, dfrA1-sat1, respectively.

Conclusions

The finding of present study revealed a high prevalence of integrons especially class 1 among MDR K. pneumoniae isolates from nosocomial infections in Kashan, which led to rapid extension of MDR strains.

New Delhi metallo-β-lactamase-1-producing Klebsiella pneumoniae isolates in hospitalized patients in Kashan, Iran

BACKGROUND AND OBJECTIVES

New Delhi metallo-ß-lactamase (NDM) is a newly emerging metallo-ß-lactamases, which can destroy all β-lactams including carbapenems. Therefore, this study aimed at evaluating New Delhi metallo-ß-lactamase-1-production in clinical isolates of Klebsiella pneumoniae in Kashan, Iran.

MATERIALS AND METHODS

In a cross-sectional study, 181 K. pneumoniae isolates were collected from clinical samples of patients, who referred to Shahid Beheshi hospital in Kashan during November 2013 and October 2014. Antimicrobial susceptibility patterns were determined using disk diffusion method, according to CLSI guidelines. Metallo-ß-lactamase (MBL) production was identified among imipenem-resistant K. pneumoniae isolates using imipenem-EDTA double disk synergy test (EDTA-IMP DDST). PCR method and sequencing were used to detect integron Class 1 and bla_NDM-1 gene. Statistical analyses were performed using SPSS software Version 16.

RESULTS

Of the 181 K. pneumoniae isolates, 36 (19.9 %) were imipenem-resistant strains. A total of 28 out of 36 (77.7%) imipenem-resistant K. pneumoniae isolates were identified as MBL producer strains. Also, 150 (82.9%) K. pneumoniae isolates carried intI1 gene, and 20 (11.1%) K. pneumoniae isolates harbored bla_NDM-1 gene.

CONCLUSION

Our study revealed a high frequency of MBL production and the presence of bla_NDM-1 among K. pneumoniae strains, especially among hospitalized patients, which is alarming. Moreover, the presence of Class 1 integrons in all multi-drug resistant K. pneumoniae isolates highlights the risk of rapid spread of the resistance genes, especially in clinical settings.

Bacterial Contamination of Iranian Paper Currency and Their Antibiotic Resistance Patterns

Background: Paper banknotes would be a vector for transmission of pathogenic microorganisms through handling. Objective: This study aimed to determine bacterial contamination of Iranian paper currencies in circulation and their antibiotic resistance patterns. Materials and Methods: In this study, 337 currency notes of different value were collected from markets, shops, restaurants, bus stations and banks in Kashan, Iran during April 2015 to March 2016. The currency notes transferred to microbiology laboratory and were tested for bacterial contamination using standard microbiological methods. Antibiotic resistance patterns of isolated bacteria were determined by disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) standards. The results and data were analyzed using descriptive statistics. Results: Of 337 currency notes, 262 (77.7%) were identified with bacterial contamination. Bacteria isolated from currency notes were as follows: Bacillus spp 113 (43.1%), coagulase-negative staphylococci 99 (37.7%), Escherichia coli 20 (7.6%), Enterococci species 14 (5.3%), Staphylococcus aureus 8 (3.1%), Klebsiella spp 4 (1.5%), Shigella species 2 (0.8%), and Pseudomonas species 2 (0.8%). The most and least contaminated currency notes were 50000 and 500 Rials, respectively. The highest resistance rates in gram-negative rods were against nalidixic acid, and ampicillin. However, the highest resistance rates in S. aureus, coagulase-negative staphylococci and Enterococci species were against ampicillin, erythromycin and tetracycline. Conclusion: Our study revealed that the bacterial contamination among Iranian paper currency in circulation especially those obtained from certain sources including shops and bus stations is high and in most cases these bacterial isolates are antibiotic-resistant strains.

Evaluation of pathogenicity islands in uropathogenic Escherichia coli isolated from patients with urinary catheters

INTRODUCTION

Uropathogenic Escherichia coli (UPEC), an important causative agent of urinary tract infections (UTIs), carries virulence factors which are clustered on pathogenicity islands (PAIs). The goal of this study was to characterize the PAIs among the UPEC isolated from patients with urinary catheters.

METHODOLOGY

A descriptive cross-sectional study was designed and from December 2014 to April 2015, 78 non-duplicate E. coli were collected from hospitalized patients with UTIs, including patients with and without indwelling urinary catheters. Two multiplex polymerase chain reaction (PCR) assays were performed to evaluate the presence of the eight most studied PAIs (I 536, II 536, III 536, IV536, I CFT073, II CFT073, PAI IJ96, and PAI IIJ96).

RESULTS

Of 78 patients with a UTI 31 (39.7%) used indwelling catheters. Of these 31 patients, 27 (87.1%) carried PAIs markers, including 25 (80.6%) PAI IV536, 12 (38.7%) PAI ICFT073, 6 (19.4%) PAI IICFT073, 6 (19.4%) PAI III536 and 3 (9.7%) PAI II536. PAI I536, PAI IJ96, and PAI IIJ96 were not detected in the UPEC strains.

CONCLUSIONS

The findings of this study revealed that the frequency of PAI markers in UPEC isolates from patients with indwelling urinary catheters was high. The rate of multiple PAIs carriage was notable among those patients, suggesting that UPEC strains that colonize the indwelling urinary catheters have the potential to cause complicated urinary infections. PAI ICFT073, which was found in association with pyelonephritis, prostatitis, and sepsis, could be considered as a target for medical interventions.

Evaluation of Metallo-β-Lactamase-Production and Carriage of bla-VIM Genes in Pseudomonas aeruginosa Isolated from Burn Wound Infections in Isfahan

Background

Metallo-β-lactamase-production among Gram-negative bacteria, including Pseudomonas aeruginosa, has become a challenge for treatment of infections due to these resistant bacteria.

Objectives

The aim of the current study was to evaluate the metallo-β-lactamase-production and carriage of bla-_VIM genes among carbapenem-resistant P. aeruginosa isolated from burn wound infections.

Patients and Methods

A cross-sectional study was conducted from September 2014 to July 2015. One hundred and fifty P. aeruginosa isolates were recovered from 600 patients with burn wound infections treated at Imam-Musa-Kazem Hospital in Isfahan city, Iran. Carbapenem-resistant P. aeruginosa isolates were screened by disk diffusion using CLSI guidelines. Metallo-β-lactamase-producing P. aeruginosa isolates were identified using an imipenem-EDTA double disk synergy test (EDTA-IMP DDST). For detection of MBL genes including bla-_VIM-1 and bla-_VIM-2, polymerase chain reaction (PCR) methods and sequencing were used.

Results

Among the 150 P. aeruginosa isolates, 144 (96%) were resistant to imipenem by the disk diffusion method, all of which were identified as metallo-β-lactamase-producing P. aeruginosa isolates by EDTA-IMP DDST. Twenty-seven (18%) and 8 (5.5%) MBL-producing P. aeruginosa isolates harbored bla-_VIM-1 and bla-_VIM-2 genes, respectively.

Conclusions

Our findings showed a high occurrence of metallo-β-lactamase production among P. aeruginosa isolates in burn patient infections in our region. Also, there are P. aeruginosa isolates carrying the bla-_VIM-1 and bla-_VIM-2 genes in Isfahan province.

Prevalence of CTX-M-Type and PER Extended-Spectrum β-Lactamases Among Klebsiella spp. Isolated From Clinical Specimens in the Teaching Hospital of Kashan, Iran

Background:

Extended-spectrum β-lactamases (ESBLs) is one of the most important mechanisms of resistance to β-lactams especially among Enterobacteriaceae family including Klebsiella spp. Different types of extended-spectrum β-lactamases including CTX-M-type and PER enzymes are identified among gram negative bacteria.

Objectives:

The current study aimed to determine the prevalence of CTX-M-type and PER extended-spectrum β-lactamases among Klebsiella spp. isolated from clinical specimens in the teaching hospital of Kashan, Iran.

Patients and Methods:

One hundred Klebsiella spp. were isolated from clinical specimens of hospitalized patients at Shahid-Beheshti hospital from December 2012 to November 2013. Disk diffusion method was used to determine the susceptibility of these isolates to 14 different antimicrobial agents; disks were purchased from MAST company (United Kingdom). The phenotypic double disk synergy confirmatory test was used to screen the isolates to produce extended-spectrum β-lactamase. DNAs of isolates were extracted using boiling method and PCR assay was used to characterize the bla_CTX-M type and bla_PER genes. The purified PCR products were sent to Macrogen research company (Korea) for sequencing.

Results:

Of the total 100 Klebsiella isolates, %93 was susceptible to imipenem. Resistance to ampicillin, ceftazidime, ceftriaxone, aztreonam and cefotaxime was (92%), (67%), (65%), (64%) and (59%), respectively. The phenotypic confirmatory test (PCT) confirmed that 35% (n = 35) of the isolates were ESBL-producing Klebsiella strains. The prevalence of bla_CTX-M type and bla_RER genes among Klebsiella isolates were 28% (n = 28) and 9% (n = 9), respectively.

Conclusions:

The prevalence of ESBL-producing Klebsiella strains in Shahid-Beheshti hospital in Kashan has increased. The study concluded that there was a high prevalence of the bla_CTX-M type gene among ESBL positive isolates.

Characterization of CTX-M-Type Extend-Spectrum β-Lactamase Producing Klebsiella spp. in Kashan, Iran

CONTEXT

The CTX-M family consists of more than 50 β-lactamases, which are grouped on the basis of sequences into five subtypes including CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9 and CTX-M-25.

OBJECTIVES

The current study aimed to detect subtypes of CTX-M extended-spectrum β-lactamases (ESBLs) among ESBL positive Klebsiella isolates from patients in Kashan, Iran.

MATERIALS AND METHODS

A total of 100 clinical isolates of Klebsiella were collected and the isolates, which showed resistance or reduced susceptibility to cefotaxime, ceftazidime and/or aztreonam by the disk diffusion method were selected. These isolates were identified as ESBL-producing isolates by double disk synergy tests using clavulanic acid, cefotaxime, ceftazidime and aztreonam. The blaCTX-M type determinants were identified by the Polymerase Chain Reaction (PCR) method followed by DNA sequencing.

RESULTS

Of the 100 Klebsiella isolates, 41 (41%) demonstrated resistance or reduced susceptibility to ceftazidime and/or aztreonam and 35% (n = 35) were ESBL-producers. Twenty-eight (8o%) of the ESBL-producing isolates carried the blaCTX-M type genes. Based on PCR assays and sequencing of blaCTX-M genes, CTX-M-1, CTX-M-2 and CTX-M-9 were identified in 21 (60%), 15 (42%) and nine (34%) of these isolates, respectively (GenBank accession numbers KJ803828-KJ803829).

CONCLUSIONS

Our study showed that the frequency of blaCTX-M genes among Klebsiella isolates in our region is at an alarming rate. Also, we found a high prevalence of blaCTX-M-1 β-lactamase in Klebsiella isolates in Kashan.

Biofilm Formation and Virulence Factors Among Pseudomonas aeruginosa Isolated From Burn Patients

BACKGROUND

Pseudomonas aeruginosa possesses a variety of virulence factors and infections caused by multidrug-resistant P. aeruginosa (MDRPA) in burn patients are a public health problem.

OBJECTIVES

The aim of this study was to determine the antibiotic resistance pattern, the biofilm formation, the prevalence of MDRPA and two virulence genes (nan1 and exoA) among P. aeruginosa isolated from burn patients.

PATIENTS AND METHODS

A total of 144 isolates of P. aeruginosa were collected from burn patient at the Burn Centre of Tehran, Iran, between March 2013 and July 2013. Antibiotic susceptibility test was performed via agar disk diffusion method. The ability of producing biofilm was examined by crystal violet microtiter plate assay and the prevalence of the exoA and nan1 genes among the isolates was determined by polymerase chain reaction (PCR).

RESULTS

A high rate of resistance was seen against ciprofloxacin (93.7%), aztreonam (86.8%), piperacillin (85.4%), ceftazidime (82.6%), amikacin (82%) and imipenem (79.2%). In total, 93.1% of the isolates were characterized as MDRPA. Biofilm formation was seen in 92.4% of the isolates. The prevalence of the exoA and nan1 genes were 75% and 11.8% among the isolates, respectively.

CONCLUSIONS

The high rate of MDRPA and its ability to produce biofilm is an alarm for public health. The statistical analysis showed that biofilm production in the MDRPA isolates was significantly higher than that in the non-MDRPA isolates (P < 0.001).

Molecular clonality and detection of class 1 integron in multidrug-resistant Salmonella enterica isolates from animal and human in Iran

A total of 70 multidrug-resistant (MDR) Salmonella isolates (44 human and 26 poultry) were examined. The conserved segment-PCR, restriction fragment length polymorphism-PCR analysis, and DNA sequencing were used to determine the presence and cassette content of integrons. The genetic relatedness among the isolates was examined by pulsed-field gel electrophoresis (PFGE). The rate of integron carriage for MDR Salmonella isolates was 91.4% and integron-positive isolates belonged to six distinct serovars. Out of 64 integron-positive isolates, only four Salmonella Paratyphi C isolates could transfer integrons to Escherichia coli K12 by conjugation. Thirty-three PFGE types were detected in 52 integron-positive isolates, including 22, 4, 3, 2, 1, and 1 patterns among Salmonella serovars Enteritidis, Typhimurium, Paratyphi C, Paratyphi B, Paratyphi A, and Havana, respectively. The human and poultry Salmonella Enteritidis isolates from different regions with identical integrons had closely related PFGE patterns. Of the four integron-positive Salmonella Typhimurium isolates, the two poultry isolates with identical integron had very closely related PFGE patterns whereas the two human isolates with different integrons showed unrelated PFGE patterns. PFGE showed undistinguishable patterns in Salmonella Paratyphi C isolates with identical cassettes but revealed relatively unrelated patterns in those with different cassettes. Relatively unrelated and identical PFGE patterns were found in two Salmonella Paratyphi B and three Salmonella Paratyphi A isolates with the same integrons, respectively. In conclusion, PFGE patterns demonstrated more genetic relatedness among each Salmonella serovar with identical class 1 integrons than the same serovar with different class 1 integrons.

Virulence Genes and Antimicrobial Resistance Pattern in Uropathogenic Escherichia coli Isolated From Hospitalized Patients in Kashan, Iran

Background:

Urinary tract infection (UTI) is one of the most prevalent infectious diseases. Uropathogenic Escherichia coli (UPEC), as the most important cause of UTI, are associated with a number of virulence factors.

Objectives:

The current study aimed to investigate the virulence associated determinants as well as their patterns of antibiotic resistance in UPEC isolated from hospitalized patients with UTI.

Materials and Methods:

A total of 150 E. coli isolates were collected from patients with UTI from December 2012 to June 2013 in Kashan, Iran. Antimicrobial susceptibility screening of 12 antibiotics was determined using disk diffusion method. Polymerase Chain Reaction (PCR) assay was used to detect virulence-related genes in UPEC strains. The purified PCR products were sequenced.

Results:

Of the total 150 UPEC isolates, 111 (74%) were multidrug-resistant. High resistance was observed against ampicillin (81.3%), nalidixic acid (71.3%), cotrimoxazole (64.7%) and ciprofloxacin (61.3%), respectively. Eighty-four out of the 150 isolates showed resistance against the extended spectrum cephalosporins. Totally, virulence genes were detected in 126 (84%) UPEC isolates .The PCR results identified the traT gene in (74%), PAIs markers in (61.3%) and the pap gene in (16.6%) of the isolates.

Conclusions:

The traT gene and PAI markers were highly prevalent among UPEC strains isolated from patients in Kashan, Iran; therefore these determinants could be used as targets for prophylactic interventions. Also there was a high level of resistance against the antibiotics commonly used for urinary tract infection treatment. To reach better therapeutic outcomes, treatment regimens have to be modified.

Detection of virulence genes in Escherichia coli isolated from patients with cystitis and pyelonephritis

BACKGROUND

Uropathogenic Escherichia coli (UPEC) is a common cause of ascending urinary tract infections including cystitis and pyelonephritis. The purpose of this study was to investigate virulence genes among Escherichia coli isolated from patients with cystitis and pyelonephritis.

METHODS

Between December 2012 and June 2013, 150 E. coli isolates from hospitalized patients with pyelonephritis (n = 72) and cystitis (n=78) were collected at Shahid Beheshti Hospital in Kashan. A PCR assay was used to evaluate the presence of virulence genes including pap, hly, aer, sfa, cnf, afa, traT, and pathogenicity island (PAI) markers in isolates.

RESULTS

Of the total 150 UPEC isolates, 130 (86.7%) were found to carry the virulence genes studied. Nineteen different virulence patterns were identified. The most prevalent virulence pattern was UPEC including traT-PAI operons. The pap, traT, aer, hly, and PAI operons were more prevalent among patients with pyelonephritis than cystitis, and the sfa, afa, and cnf genes were not detected in any of the isolates.

CONCLUSIONS

Higher virulence gene diversity was found among pyelonephritis UPEC isolates in comparison to cystitis UPEC isolates, showing that UPEC strains that cause pyelonephritis need more virulence factors.

Detection of plasmid-mediated qnr genes among the quinolone-resistant Escherichia coli isolates in Iran

INTRODUCTION

Plasmid-mediated quinolone resistance, which complicates treatment, has been increasingly identified in Escherichia coli isolates worldwide. The purpose of this study was to identify the plasmid-mediated qnrA and qnrB genes among the quinolone-resistant Escherichia coli isolated from urinary tract infections in Iran.

METHODOLOGY

A total of 140 Escherichia coli isolates were collected between March and October 2012 from urinary tract infections in Khorram Abad, Iran. All isolates were tested for quinoloe resistance using the disk diffusion method. Also, all quinolone-resistant isolates were screened for the presence of the qnrA and qnrB genes by polymerase chain reaction. Minimum inhibitory concentrations (MICs) of ciprofloxacin for the qnr-positive isolates were determined.

RESULTS

One hundred sixteen (82.8%) of 140 Escherichia coli isolates were nalidixic acid-resistant; among them, 14 (12.1%) and 9 (7.8%) were qnrA and qnrB-positive, respectively. Two quinolone-resistant isolates harbored both qnrA and qnrB. Among 63 ciprofloxacin-resistant isolates, 14 (22.2%) and 9 (14.3%) were found to carry qnrA and qnrB genes, respectively. The ciprofloxacin MIC range was 0.25-512 µg/mL for 23 qnr-positive Escherichia coli isolates, 18 of which had MICs values of 4-512 µg/mL.

CONCLUSION

Our study shows that the frequency of plasmid-mediated quinolone resistance genes among E. coli isolates in Iran is high.

Investigation of anti-Toxocara antibodies in epileptic patients and comparison of two methods: ELISA and Western blotting

The relationship between Toxocara infection and epilepsy was previously demonstrated by several case-control studies and case reports. These previous studies were often based on the enzyme-linked immunosorbent assay (ELISA) using Toxocara excretory-secretory antigens, which are not specific due to cross-reactivity with other parasitic infections such as ascariasis, trichuriasis, and anisakiasis. An immunoblot analysis is highly specific and can detect low levels of Toxocara antibodies. Therefore, this assay may be useful in the identification of toxocariasis in epileptic patients. We examined patients who had epilepsy and healthy subjects for seropositivity for Toxocara infection by ELISA and Western blotting. Out of 85 epileptic patients, 10 (11.8%) and 3 (3.5%) persons exhibited Toxocara immunoglobulin G (IgG) antibodies responses by ELISA and by both techniques, respectively. Moreover, in the healthy group (n = 85), 3 (3.5%) persons were positive by ELISA, but none was detected by Western blotting. This study indicates that Toxocara infection is a risk factor for epilepsy in Iran. These findings strongly suggest the need to perform Western blotting immunodiagnosis, as well as the ELISA using Toxocara excretory-secretory antigens, to improve diagnosis of human toxocariasis in patients with epilepsy.

Microbial contamination of pumice used in dental laboratories

Dental appliances as well as sending and receiving prosthesis from laboratories are potential sources of cross-contamination for technicians, dentists, patients and can transmit different infectious agents as well. This study was conducted to determine the types of the microorganisms in pumice powder and pumice slurry used in dental laboratory in order to evaluate necessary disinfection control procedure in the dental settings. Twenty-four active dental laboratories of Khorram Abad participated in our study. Samples were randomly collected from prosthesis polishing containers in sterilized condition and were immediately sent to microbiology laboratory. Specimens were cultured on selective bacterial and fungal media in order to determine the microorganisms. Both oral and non-oral bacteria were recovered from pumice samples as follows: Staphylococcus aureus (15.4%), Streptococcus viridance (10.8%), Bacillus cereus (18.7%), Pseudomonas aeruginosa (12.8%), Diphtheriods (7.3%), Enterobacter cloace (4.3%), Escherichia coli (13.1%), Klebsiella pneumonia (5.4%), and Acinetobacter spp. (12.2%). The isolated fungi included Candida albicans (36.7%), other yeasts (17.3%), Fusarium spp. (13.8%), Aspergilus spp. (22.4%) and Penicillium spp. (9.8%). This study showed that polishing pumices in the form of powder or slurry were contaminated with different oral and non-oral bacteria and also fungi. Therefore, the chance of cross-contamination still severely exists, and measures should be conducted to prevent the contamination of predisposed people such as technicians, dentists and patients.

Characterization of class I integrons among Salmonella enterica serovar Enteritidis isolated from humans and poultry

A total of 84 Salmonella enterica serovar Enteritidis (S. Enteritidis) isolates, 42 of human and 42 of poultry origin, were characterized for antimicrobial resistance patterns and class I integrons. Among them, 58 (69%) S. Enteritidis were multidrug-resistant (MDR) and showed resistance to two or more antibiotic classes. By PCR assays and DNA sequencing, 50 (59.5%) S. Enteritidis isolates were found to carry class I integrons. Amplification of internal variable regions of class I integrons revealed five different arrays (0.75 kb only, 1 kb only, 1.3 kb only, both 1 and 1.2 kb, and both 1 and 1.3 kb). The integrons were further sequenced and the dfrA25 (0.75 kb), aadA1 (1 kb), aadA2 (1 kb), bla(PSE1) (1.2 kb) aadA6-orfD (1.3 kb) gene cassette arrays were identified. Ciprofloxacin minimum inhibitory concentration (MIC) values for the three isolates that showed resistance or reduced susceptibility via the disc diffusion method were 0.5-4 μg mL(-1), although only three isolates exhibited resistance to cefteriaxone (MIC: 128-256 μg mL(-1)) and four isolates were resistant to florfenicol (MIC: 32-128 μg mL(-1)). In conclusion, the high rates of multidrug-resistance and class I integrons found among S. Enteritidis isolates in humans and poultry in Tehran suggest that efforts are needed to confine the prevalence of MDR Salmonella isolates.