Serologic evaluation of cytomegalovirus (CMV), Toxoplasma gondii and Brucella in schizophrenia patients.

Background: Infectious agents are considered as a possible cause of schizophrenia. The aim of this study was to evaluate the serum levels of cytomegalovirus (CMV), Toxoplasma gondii and Brucella antibodies in schizophrenia patients compared with the control group. Methods: This cross-sectional study was performed on 75 patients with schizophrenia who were clinically diagnosed with schizophrenia using the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) by two independent psychiatrists. As the controls, 75 sex and age-matched individuals were selected from orthopedic and surgical wards, who were admitted because of trauma. Anti-Toxoplasma gondii IgG antibody was detected by Abbott's company diagnostic kit. To detect anti-Brucella IgG antibodies, the enzyme-linked immunosorbent assay (ELISA) test with Vircell diagnostic kit was used. Quantitative luminescence (CLIA) method using Abbott diagnostic kit was also used to detect anti-cytomegalovirus IgG antibody (CMV IgG avidity). Results: There was not any clinically significant differences in the mean value of Toxoplasma, CMV and Brucella IgG antibodies between schizophrenia and control group. However, considering cut-off point for these tests and further analysis with non-parametric tests showed clinically significant difference between two groups at cut-off point 1.1 for anti-Brucella IgG antibody which indicated more positive samples in schizophrenia group (24 out of 75) than control group (12 out of 75) with a p-value less than 0.05 (0.046). Conclusion: The results of the present study showed no association between toxoplasmosis infection and CMV and schizophrenia. However, there might be a positive correlation between anti-Brucella IgG antibody and schizophrenia.

Analysis of virulence genes and molecular typing of Listeria monocytogenes isolates from human, food, and livestock from 2008 to 2016 in Iran.

The frequency of Listeria monocytogenes isolates collected from a total of 1150 samples including food (n = 300), livestock (n = 50), and human clinical (n = 800) was evaluated during 2008-2016. Antimicrobial resistance patterns, virulence factors, and molecular characteristics of these isolates were analyzed using disk diffusion method, sequencing, serotyping, and pulsed-field gel electrophoresis (PFGE). The analysis of 44 L. monocytogenes isolates showed that 72.7% (32 of 44) of all the isolates belonged to Serotype 1/2c, and 15.9% (7 of 44) belonged to Serotype 3c. All 44 isolates were resistant to one or more antimicrobial agents with the most frequent resistance to penicillin (75%) and tetracycline (47.7%). Of the 44 L. monocytogenes strains, 100, 69.2, and 62.5% of livestock, human, and food strains were resistant to penicillin, respectively. Using pulsed-field gel electrophoresis (PFGE) technique, the isolates' genetic diversity was determined, and 28 PFGE patterns with 8 common (CT) and 20 single types (ST) were identified. This study highlights the high prevalence of Serotype 1/2c in clinical and livestock samples, while different serotypes were observed in food samples. The presence of rare serotypes such as 4c, belonging to the Lineage III, as well as 4e and 1/2c which are infrequent in Iran indicates that paying attention to uncommon serotypes, especially 1/2c, during the listeriosis outbreaks is necessary.

A multicenter study of ß-lactamase-producing Klebsiella pneumoniae isolated from university teaching hospitals of Urmia, Iran.

INTRODUCTION: Klebsiella pneumoniae is an opportunistic pathogen accounting for 5-7% of hospital acquired infections. The emergence of carbapenem-resistant Klebsiella pneumoniae has been increasing rapidly over recent years causing many therapeutic problems worldwide. This study aimed to research the antimicrobial resistance profile, detect ß-lactamase genes among clinical isolates of K. pneumoniae, and determine their clonal relatedness. METHODOLOGY: All Klebsiella pneumoniae isolates were obtained from teaching hospitals in Urmia, Iran. Antimicrobial susceptibility testing was done by the disk diffusion method. Furthermore, minimum inhibitory concentrations of imipenem were determined by applying Etest strips. Screening of ß-lactamase-producing isolates was performed by the combined disk method and modified Hodge test. The detection of ß-lactamase genes was conducted by polymerase chain reaction (PCR), and isolates' clonal relatedness was evaluated by random amplified polymorphic DNA (RAPD)-PCR. RESULTS: Overall, 45 out of 182 (24.7%) K. pneumoniae isolates were non-susceptible to imipenem. The combined disk method and modified Hodge test revealed that 93.3% and 71.1% of the imipenem non-susceptible isolates were ß-lactamase producers, respectively. The presence of blaVIM, blaNDM, blaKPC, and blaIMP genes was confirmed in 48.9%, 15.6%, 11.1%, and 6.7% of the ß-lactamase-producing isolates, respectively. RAPD-PCR revealed that 73% of these isolates were classified into six different clusters. CONCLUSIONS: A relatively high prevalence of ß-lactamase genes was seen among multidrug-resistant isolates of K. pneumoniae. Most patients infected with ß-lactamase-producing isolates had a history of long-term hospitalization and nosocomial infections. The predominance of ß-lactamase genes in intensive care unit and internal units alarm clinicians to the growth of hospitalization and mortality rates.

Nocardia farcinica meningitis in a patient with high-grade astrocytoma.

We describe a case of 91-year-old male with astrocytoma who developed meningitis caused by Nocardia farcinica. He had a past medical history of anaplastic astrocytoma grade III. Endocranial computed tomography (CT) scan revealed mass lesion in the left occipital region associated with perilesional edema, without evidence of midline shift issue. The analyses of cerebrospinal fluid (CSF) revealed neutrophilic pleocytosis, hyperproteinorrachia and hypoglycorrhachia. Combined antimicrobial therapy was initiated (vancomycin, meropenem, acyclovir). CSF culture revealed Nocardia farcinica. Susceptibility testing revealed intermediate sensitivity to meropenem and antibiotic treatment was switched to trimethoprim-sulfamethoxazole and imipenem. After 7 days of treatment the patient developed progressive dyspnea. The chest CT scan revealed bilateral pleural effusion and alveolar infiltrate mostly in the right lobe. Ceftriaxone was added to the therapy, but the outcome was lethal. Nocardia spp. should be considered as differential diagnosis in the patients with brain tumor or meningitis in the setting of immune suppression and corticosteroid use. CSF cultures should be incubated longer with aim to allow fastidious organisms to grow, such as Nocardia spp.

The association of interferon-gamma, interleukin-4 and interleukin-17 single-nucleotide polymorphisms with susceptibility to tuberculosis.

Susceptibility to tuberculosis and progression of the disease depend on interactions between the bacterial agent, host immune system, and environmental and genetic factors. In this case-controlled study, we aimed to determine the role of single-nucleotide polymorphisms of interferon-gamma, interleukin-4 and interleukin-17 in susceptibility to tuberculosis. Genomic DNA was extracted from peripheral blood samples of patients and controls. The association of single-nucleotide polymorphisms in interleukin-4 (-590C/T), interleukin-17 (-152A/G) and interferon-gamma (+874T/A) was investigated by polymerase chain reaction (PCR)-restriction fragment length polymorphism and amplification refractory mutation system-PCR. A total of 76 tuberculosis patients and 119 healthy individuals were included in this study. The interferon-gamma (+874T/A) TA genotype was significantly associated with susceptibility to tuberculosis in patients compared to controls (OR = 1.76; 95%CI = 0.84-3.71; p = 0.007), while the interferon-gamma (+874T/A) TT genotype (OR = 0.51; 95%CI = 0.19-1.36; p = 0.007) had protective effects against tuberculosis and was related to a low risk of tuberculosis development. The difference between allelic and genotypic frequencies of interleukin-4 (-590C/T) between patients and controls was not significant (p = 0.46). Multivariate logistic regression analysis revealed that the interleukin-17 (-152A/G) AG genotype (OR = 2.27; 95%CI = 1.19-4.34; p = 0.03) and AA genotype (OR = 1.03; 95%CI = 0.43-2.44; p = 0.03) were significantly different between patients and controls. In conclusion, single-nucleotide mutations in different cytokine genes may have protective effects or increase the risk of tuberculosis.

Evaluation of Carbapenem Resistance Mechanisms and Its Association with Pseudomonas aeruginosa Infections in the Northwest of Iran.

The aims of this study were to determine carbapenem resistance mechanisms, molecular epidemiological relationship, clinical impact, and patient outcome of carbapenem-resistant Pseudomonas aeruginosa (CRPA) infections. A total of 42 nonduplicated CRPA were recovered from Urmia, Iran. Antimicrobial susceptibility tests were carried out using phenotypic methods. The carbapenem resistance mechanisms such as carbapenemase genes, efflux pump hyperexpression, AmpC overproduction, and OprD gene downregulation were determined by phenotypic and molecular methods. Eighteen metallo-ß-lactamase (MBL) producer isolates were found to be sensitive to amikacin. Among the CRPA, 52.3%, 26.1%, 26.1%, and 59.5% were identified as carbapenemase, efflux pump hyperexpression, AmpC overproduction, and reduced expression OprD gene, respectively. Random Amplified Polymorphic DNA analysis yielded 25 distinct profiles. Most MBL-positive isolates were recovered from patients hospitalized in urology and internal wards with urinary tract infections. Most of the strains showed downregulation of porin. The clonal distribution of the strains was related to carbapenem resistance mechanisms (most of MBL producers belong to the same clones) and the same hospital wards where the isolates were collected. The study demonstrates that the main risk factor of MBL-related infections was hospitalization in non-intensive wards. Amikacin was considered a very efficient antibiotic to treatment of MBL-producing CRPA isolates. Our results showed that OprD downregulation and IMP-type MBL are the main carbapenem resistance mechanisms in CRPA isolates from northwest of Iran.

Evaluation of anti-bacterial effects of nickel nanoparticles on biofilm production by Staphylococcus epidermidis.

BACKGROUND AND OBJECTIVES: Staphylococcus epidermidis produces biofilm by extracellular polysaccharides, causing bacterial adherence to different surfaces. Anti-microbial effects of nickel nanoparticles on some bacterial strains such as S. aureus and Escherichia coli have been determined in limited studies. The aim of the present study is to examine the inhibitory effect of nickel nanoparticles on biofilm formation using clinical isolates of S. epidermidis and its hemolytic effect on human red blood cells. MATERIALS AND METHODS: Twenty two S. epidermidis isolates were collected and identified by standard microbiological methods. Microtiter plate method was used to determine the biofilm production in bacterial isolates. The amounts of biofilm formation by isolates in the presence of 0.01, 0.05, 0.1, and 1 mg/mL concentrations of nickel nanoparticles were measured. Hemolytic activity of different concentrations of nickel nanoparticles was measured on human RBC suspensions. RESULTS: Twenty isolates were strong, and two isolates were moderate biofilm producers. Biofilm formation significantly decreased in the presence of 0.05, 0.1, and 1 mg/mL of nickel nanoparticles (p<0.05). Although in the presence of 0.01 mg/mL of nickel nanoparticles, decrease in biofilm formation was observed but it was not statistically significant (p=0.448). Slight hemolytic activity was seen in the presence of nickel nanoparticles. CONCLUSION: In this study, the ability of biofilm production was demonstrated for all clinical isolates of S. epidermidis. On the other hand, the lowering effects of nickel nanoparticles on biofilm formation were observed.

Eradication of methicillin resistant S. aureus biofilm by the combined use of fosfomycin and ß-chloro-L-alanine.

BACKGROUND AND OBJECTIVES: Biofilm formation is an important virulence factor for methicillin-resistant Staphylococcus aureus (MRSA). Fosfomycin is a borad-spectrum antibiotic with inhibitory effects on biofilm production and ß-Chloro-L-alanine (ß-CLA) is an amino acid analog. The aim of this study was to determine effect of the combination of fosfomycin and ß-CLA on biofilm production by MRSA isolates. Also, the clonal relatedness of the isolates was evaluated. MATERIALS AND METHODS: To determine the ability of biofilm production by 42 MRSA isolates, microtiter plate method was used. Antibacterial activities of fosfomycin and ß-CLA were investigated by determining MICs and MBCs. Antibiofilm activities were measured in the presence of sub-MIC concentrations of fosfomycin, ß-CLA or a combination of both. RAPD-PCR was used for investigating the clonal relationship between isolates by the two specific primers. RESULTS: 21.4% of isolates were strong and 5% were moderate biofilm producers. The effect of fosfomycin plus ß-CLA treatment on biofilm production was significantly different from non-treated, fosfomycin and ß-CLA groups (p=0.00, 0.004 and 0.000 respectively). RAPD-PCR analysis revealed that the RAPD1 primer had more discriminatory power. The Sizes of RAPD-PCR bands ranged from 150 bp to 1500 bp and the number of bands varied from 1 to 13. CONCLUSION: Clonal relatedness of isolates showed that the majority of biofilm producing isolates had identical pattern and only three isolates showed more than 80% similarity. The combination of fosfomycin and ß-CLA could be introduced as an excellent mixture for eradication of MRSA biofilms in vitro.

Carbapenem inactivation: a very affordable and highly specific method for phenotypic detection of carbapenemase-producing Pseudomonas aeruginosa isolates compared with other methods.

This investigation was undertaken to compare phenotypic and molecular methods for detection of carbapenemase-producing Pseudomonas aeruginosa. A total of 245 non-duplicated isolates of P. aeruginosa were collected from hospitalized patients. Disc diffusion method was used to identify carbapenem-resistant bacteria. Three phenotypic methods, including Modified Hodge Test (MHT), Modified Carba NP (MCNP) test and Carbapenem Inactivation Method (CIM) were used for investigation of carbapenemase production. In addition, polymerase chain reaction (PCR) was used to detect carbapenemase encoding genes. Of 245 P. aeruginosa isolates investigated, 121 isolates were carbapenem-resistant. Among carbapenem-resistant isolates, 40, 39 and 35 isolates exhibited positive results using MHT, MCNP test and CIM, respectively. PCR indicated the presence of carbapenemase genes in 35 of carbapenem-resistant isolates. MHT showed low sensitivity and specificity for carbapenemase detection among P. aeruginosa isolates in comparison to PCR. CIM was most affordable and highly specific than MCNP test compared with the molecular method.

A multiresistant clone of Pseudomonas aeruginosa sequence type 773 spreading in a burn unit in Orumieh, Iran.

Herein, we describe the phenotypic and genotypic characterization of a multiresistant clone of Pseudomonas aeruginosa disseminating in a burn unit in Orumieh, Iran. A total of 58 isolates of P. aeruginosa were collected during August 2007 and June 2008. Minimum inhibitory concentrations (MICs) of P. aeruginosa isolates were determined against 11 antimicrobial agents by E test. Serotyping, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) were used for studying the clonal relationship among the isolates. Antibiotic susceptibility testing revealed that most of the isolates were multidrug resistant and colistin was the antibiotic with the highest activity. Pseudomonas aeruginosa isolates fell into nine different serotypes, and O10 and O11 were the most common. PFGE analyses showed 12 different genotypes and 68.1% of isolates showed more than 80% similarity, indicating possible clonal relatedness. These isolates were found to belong to the same sequence type, ST773. This sequence type has earlier been reported from China, and a double locus variant of this ST has been found earlier in France in a PER-1 extended-spectrum ß-lactamase-producing P. aeruginosa.

Prevalence of PER-1- type Extended-Spectrum Beta-Lactamaes in Clinical Strains of Pseudomonas aeruginosa Isolated from Tabriz, Iran.

OBJECTIVES: The aim of this study was to investigate the presence of PER-1-type ESBLs in drug resistant Pseudomonas aeruginosa isolates. MATERIALS AND METHODS: During one-year period (2008-2009), following isolation and identification of 56 P. aeruginosa, the E-test method was performed for determination of minimal inhibitory concentration of ceftazidim. The isolates that they had MIC≥16 µg/ml against ceftazidim were used for determination of ESBL-producing by combined disk test (CDT) and double disk synergy test (DDST) methods. Bla PER-1 gene was investigated by PCR. P. aeruginosa KOAS was used as positive control. RESULTS: Twenty-nine (51.78%) out of fifty six isolates had MIC≥16 µg/ml to ceftazidime, twenty two (75.86%) of them were ESBL producers. Some isolates (27.5%) contained bla PER-1 gene. CONCLUSION: PER-1-type ESBLs producing P.aeruginosa has not been reported previously in but there has been a rather high prevalence of it.

Detection of metallo-ß-lactamase-encoding genes among clinical isolates of Pseudomonas aeruginosa in northwest of Iran.

The prevalence of metallo-ß-lactamase (MBL) production among 104 clinical isolates of Pseudomonas aeruginosa from northwest of Iran was investigated by phenotypic and polymerase chain reaction (PCR) methods. Thirty-nine (37.50%) of isolates were MBL positive by double-disk synergy test. Results of PCR revealed that 18 (17.31%) and 6 (5.77%) imipenem nonsusceptible isolates of P. aeruginosa carried bla(VIM) and bla(IMP) genes respectively, while 92.4% (62/67) of isolates contained class 1 integron gene. This is the first report of MBL-producing P. aeruginosa from northwest of Iran.

A case of Aspergillus fumigatus mediastinitis after heart surgery in Madani Heart Center, Tabriz, Iran.

Reported here is the case of a 60-year-old male diabetic patient with mediastinitis caused by Aspergillus fumigatus following an open heart surgery that was successfully treated. A review of literature revealed that A. fumigatus as a cause of mediastinitis has been rarely described. Aspergillus infection should be considered in the differential diagnosis of mediastinitis after cardiac surgery, especially in a clinical setting of unexplained sepsis or nonhealing wound infection despite apparently adequate treatment.