Evaluation of chemical and microbial quality of food in northern Iran

BACKGROUND

Iran is one of the developing countries and foodborne diseases commonly impose problems for public health, the health care system and the economy. Therefore, this study aimed to evaluate the chemical and microbial quality of food in northern Iran.

METHODS

This cross-sectional study was conducted in 2019. This study was performed on food samples obtained in a straightforward way while visiting food preparation and distribution centers in Babol. Tests related to different food types were performed by laboratory experts. Data collection with a checklist: date and place of sampling, number of samples, type of food, type of test, compliance of results with standards. Data were analyzed by SPSS22 and descriptive statistics, Chi-square and t-test.

RESULTS

1043 food samples were tested from 5 groups of dairy products, protein, cereals, vegetables and other food groups. The highest number of samples in the cereal group was 767 samples (73.53%). In the cereal group, most samples were breads. The pH of 11.67% of breads and the salt in 21.49% of breads did not match the standard. The blankit (sodium hydrosulfite) on bread dough were negative. Moisture, gluten, ash and pH match with the standards in all flour samples. The results of microbial tests on sweets and ice cream showed that Escherichia coli and Staphylococcus aureus and Salmonella were negative. Enterobacter aerogenes was positive in 8.20% of sweets, mold and yeast were positive in 19.58%. The results of microbial tests on buttermilk and yogurt, grilled meat and chicken sandwiches, vegetables and salads showed that bacteria Escherichia coli and Staphylococcus aureus and all microorganisms were negative. Mold tests were positive in 11.12% of juice samples.

CONCLUSIONS

The results showed that the foods and drinks supplied in food and drink preparation and distribution centers in Babol in 2019 were of good chemical and microbial quality. In some food groups the results of microbial and chemical testings were negative, i.e. without contamination. Less than 20% of products in the group of cereals and protein products did not match with the standards, which is a satisfactory result compared to other studies conducted in different cities of Iran. These good results for food quality can be explained bythe constructive performance of food health experts that made good controling, monitoring, and food health and hygiene education.

Genetic diversity of healthcare-associated methicillin-resistant Staphylococcus aureus isolates from Southern Iran

Staphylococcus aureus is a common pathogen causing hospital infections. The increasing rate of healthcare-associated infections caused by methicillin-resistant Staphylococcus aureus (MRSA) in developing countries has led to many public health problems. This study aimed to investigate the molecular epidemiology as well as the antibiotic resistance pattern of clinical isolates of MRSA from Southern Iran. A total of 135 S. aureus isolates were collected from the patients referred to three hospitals in South Iran. The phenotypic and genotypic diagnosis of MRSA isolates was performed by disk diffusion and PCR methods, respectively. The antibiotic resistance pattern for MRSA isolates was performed using Kirby-Bauer method. The molecular epidemiology of isolates was performed by MLST, Spa typing and SCCmec typing. From 135 S. aureus isolates, 50 (37%) MRSA strains were detected from which two different sequence types including ST239 and ST605 were identified. SCCmec type III was the most common profile (50%) and t030 was the predominant spa type (48%) among the strains. The MRSA isolates had the highest resistance to penicillin (100%), tetracycline (88%), levofloxacin (86%), ciprofloxacin (84%), erythromycin (82%), gentamicin (80%), and clindamycin (78%). The results of this study show that the most common genetic type among the MRSA isolates was ST239-SCCmec III/t030. The rapid and timely detection of MRSA and the administration of appropriate antibiotics according to the published antibiotic resistance patterns are essential. Furthermore, the continuous and nationwide MRSA surveillance studies are necessary to investigate clonal distribution and spreading of MRSA from community to hospitals.

An exceptionally long CA-repeat in the core promoter of SCGB2B2 links with the evolution of apes and Old World monkeys

We have recently reported a genome-scale catalog of human protein-coding genes that contain "exceptionally long" STRs (≥6-repeats) in their core promoter, which may be of selective advantage in this species. At the top of that list, SCGB2B2 (also known as SCGBL), contains one of the longest CA-repeat STRs identified in a human gene core promoter, at 25-repeats. In the study reported here, we analyzed the conservation status of this CA-STR across evolution. The functional implication of this STR to alter gene expression activity was also analyzed in the HEK-293 cell line. We report that the SCGB2B2 core promoter CA-repeat reaches exceptional lengths, ranging from 9- to 25-repeats, across Apes (Hominoids) and the Old World monkeys (CA>2-repeats were not detected in any other species). The longest CA-repeats and highest identity in the SCGB2B2 protein sequence were observed between human and bonobo. A trend for increased gene expression activity was observed from the shorter to the longer CA-repeats (p<0.009), and the CA-repeat increased gene expression activity, per se (p<0.02). We propose that the SCGB2B2 gene core promoter CA-repeat functions as an expression code for the evolution of Apes and the Old World monkeys.

Molecular characterization of the first community-acquired methicillin-resistant Staphylococcus aureus strains from Central Iran

BACKGROUND

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has spread throughout the world with varying regional incidences and different staphylococcal cassette chromosome mec (SCCmec) elements in different genetic backgrounds. No information is available on CA-MRSA in Iran. A cross-sectional study was carried out among healthy students to investigate: (1) the prevalence of CA-MRSA in Central Iran, (2) the molecular epidemiology of such CA-MRSA strains, (3) the antimicrobial resistance patterns of the strains, and (4) the distribution of virulence genes in these CA-MRSA strains.

METHODS

A total of 700 nasal swabs were collected and subjected to S. aureus and MRSA-specific isolation procedures. Antimicrobial resistance patterns were determined using the disk diffusion method, and molecular typing was carried out by multi-locus sequence typing (MLST), SCCmec typing, and Staphylococcus protein A (spa) typing for all CA-MRSA isolates. PCR was used to detect various virulence genes.

RESULTS

One hundred fifty-four S. aureus strains were isolated from the anterior nares of 700 healthy students. According to the US Centers for Disease Control and Prevention definitions for CA-MRSA, seven (4.5%) isolates were confirmed as CA-MRSA. CA-MRSA isolates belonged to SCCmec types IV (n = 6) and V (n = 1). The predominant spa-type among the CA-MRSA isolates was t790 (n = 3), with single t660, t084, and t325 isolates; one isolate was not typeable. The predominant sequence type was ST22, t790, SCCmec IV in three isolates, and the four other sequence types were ST25, ST859, ST14, and ST15.

CONCLUSIONS

Iranian CA-MRSA strains are genetically diverse with an elevated prevalence of t790/ST22 SCCmec IV isolates. These findings support the need for more effective infection control measures to reduce nasal carriage and prevent dissemination of CA-MRSA in Iran.

Novel evidence of the involvement of calreticulin in major psychiatric disorders

Calreticulin (CALR) is a multi-functional protein that is strictly conserved across species. Two mRNA transcripts have been recognized for the CALR gene in humans, which use a common promoter sequence. We have recently reported mutations in the CALR promoter that co-occur with psychosis. One of those mutations at -220A increases gene expression in human BE(2)-C and HEK-293 cell lines. This mutation is the first instance of a functional cognition-deficit mutation reversing a human gene promoter to the primitive type. In the current study, we analyzed the effect of the most widely-used mood-stabilizing drug, valproic acid (VPA), on nucleotide -220 in two neuronal cell lines, LAN-5 and N2A. Remarkably, VPA increased gene expression in the cells with the wild-type -220C construct, whereas a dramatic decrease in gene expression was observed in the cell lines with the mutant construct (p<0.000004 and p<0.016, respectively). We also sequenced the 600-bp CALR promoter, and the highly conserved intron 1 sequence in an independent sample of patients afflicted with major psychiatric disorders and controls. A new case of major depressive disorder with psychotic features with the -220A mutation was identified. A novel 1-bp insertion was also detected in intron 1 at IVSI-310, in a case of amphetamine-induced psychosis. As for the psychosis-linked CALR promoter mutations identified to-date, the IVSI mutation was not detected in the control pool. This mutation creates a RREB-1 transcription factor binding site within the first intron. Our present findings identify the site of action of VPA in the CALR promoter, and introduce a novel mutation in a case of substance-induced psychosis in the first intron of CALR.

Polymorphism in the Promoter Region of the CD14 Gene and Susceptibility to Brucellosis

A single-nucleotide polymorphism in the promoter region of the CD14 gene at position 159 has been implicated in susceptibility to infectious diseases. We sought to determine the association between CD14 C-159 T functional promoter polymorphism and brucellosis in Western Iranian population where the disease is endemic. The CD14 genotype was determined in 228 patients with brucellosis from a rural area and 129 healthy volunteers from the same area. The prevalence of genotype TT was significantly higher in the patients while the controls showed higher prevalence of genotype CC (34.5% vs 15.5%, 15.4% vs 25.6%, P = 0.009). Multiple logistic regression analysis after adjustment for gender demonstrated that the patients who were homozygous for allele T of promoter of CD14 gene had a significantly higher risk for developing brucellosis with odds ratio of 3.03 (95% CI, 5.2, 1.75 P = 0.0004). The existence of homozygous genotype of allele T of CD14 was an independent determinant for occurrence of arthritis among the patients with brucellosis (odds ratio of 3.92 (95% CI, 2.93, 5.88, P = 0.001).Our findings provide suggestive evidence of association of the CD14 gene polymorphism with susceptibility to development of brucellosis in Iranian populations.

TLR4 polymorphism in Iranian patients with brucellosis

OBJECTIVE

Brucellosis is a zoonosis of both public health and economic significance in most developing countries. Polymorphisms in Toll-like receptor-4 (TLR4) have been reported to be associated with a blunted immune response to microbial pathogens. Information regarding any association between genetic variation of TLR4 and susceptibility to brucellosis is not available in the literatures. The main purpose of this research is to evaluate the role of polymorphic alleles of TLR4 gene in susceptibility to brucellosis.

MATERIALS AND METHODS

In this case-control study, 198 patients with brucellosis and 111 healthy volunteers matched for sex, age and geographic area were evaluated by genotyping for polymorphism in TLR4 gene (Asp299Gly) using amplification refractory mutation system (ARMS)-PCR method.

RESULTS

Allele 896G was more prevalent in patients with brucellosis compared to healthy controls (33.6% vs. 20.7%, P=0.000003). Also the frequency of G allele of TLR4 gene was significantly higher in male patients with brucellosis compared to the same sex in control group (36% vs. 21.7%, P=0.00005). Multiple logistic regression analysis demonstrated that male patients heterozygous at allele G gene had a significantly higher risk for brucellosis with an odds ratio of OR 2.89, 95% CI: 1.79-4.69, P<0.0001).

CONCLUSION

This study is the first to show an association between genetic polymorphism in TLR4 gene and susceptibility to brucellosis.

Multichannel physiological monitor plus simultaneous full-duplex speech channel using a dial-up telephone line

Because of bandwidth limitations, the Public Switched Telephone Network (PSTN) cannot normally accommodate simultaneous multichannel physiological signaling with speech. This communication describes work carried out to build a physiological monitoring system which can transmit up to six low-frequency data channels in the presence of a full-duplex speech channel using one telephone line.