Iranian Journal of Microbiology
Volume:15 Issue: 2, Apr 2023

There are conflicting views regarding face mask guidelines amongst healthcare staff to prevent transmission of coronavirus disease 2019 (COVID-19), influenza and other respiratory viral infections (RVIs). We conducted a thorough meta-analysis to statistically compare mask use versus no mask use efficacy for RVIs in healthcare settings.

Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were used for selecting researches published between 2003 and June 2022 from different databases, including Publisher Medline (PubMed), Web of Science, etc.; 6 studies qualified for inclusion. Data was pooled from in vivo randomized control, case-control and observational studies dealing with the relationship between face mask use and no use by patients or health personnel and RVI prevention in healthcare setups.

The fixed and random-effects model was carried out to determine pooled odds ratios (ORs) and their respective 95 percent confidence intervals (CIs). The results revealed that wearing a face mask significantly reduced the risk of contracting a respiratory viral illness in hospital settings, with pooled OR (95% CI) of 0.11 (0.04 to 0.33) (probability value (P) <0.08).

Masks largely succeeded in stopping respiratory virus transmission, as evidenced by the meta-analysis of 6 studies (a total of 927 individuals).

Since the coronavirus disease 2019 (COVID-19) pandemic began, several vaccines have been manufactured to subside it. This study aimed to determine the prevalence of side effects after injecting common COVID-19 vaccines available in Iran.

This cross-sectional study was accomplished on Shahid Beheshti University of Medical Sciences (Tehran, Iran) employees during January and September 2022. Eligible participants were selected based on the simple ran- dom method and interviewed about side effects after injecting COVID-19 vaccine.

The mean age of 656 participants was 38.03 ± 9.53 years, and 453 (69.1%) were female. The prevalence of post-vac- cination side effects was higher after receiving the first dose (53.2%) than the second (35.9%) and third (49.4%) doses. Across all three vaccine doses, the overall proportion of side effects was higher following AstraZeneca than the others. The most common side effect after the first dose of the vaccine was myalgia (41.9%), followed by fever (36.6%), chills (31.6%), local reactions (27.0%), headache (25.5%), and sweating (21.6%). People experienced mainly myalgia (23.3%) and fever (20.3%) after injecting the second dose of the vaccine. Additionally, the participants had myalgia (37.2%), fever (30.8%), chills (29.2%), local reactions (26.0%), and headache (24.4%) after the third dose of the vaccine.

AstraZeneca had a higher proportion of post-vaccination adverse effects than Sputnik V, Pastocovac, and Sin- opharm. The most common side effects were flu-like syndrome and local reactions at the injection site. Furthermore, people rarely experienced life-threatening side effects. Thus, the available COVID-19 vaccines in Iran are safe.

The most appropriate approach to control the SARS-CoV-2 epidemic is the widespread adoption of vaccination. Several vaccines against SARS-CoV-2 have been developed and authorized for use in various geographical regions. The aim of this study is to evaluate the efficacy of the vaccination agents presently utilized by healthcare workers (HCWs), and to investigate whether different COVID-19 vaccines would result in the alleviation of symptoms and the severity of clinical presentation.

This multi-center survey was conducted on 329 vaccinated HCWs who were reinfected with COVID-19 between January 8, 2021 and April 8, 2021, in Tehran, Iran.

Overall, 92.1% and 70.8% of the participants had received 2 and 3 cumulative doses of COVID-19 vaccines, respectively. There were no differences between first/second and third-dose vaccines with the severity of SARS-CoV-2 infection. Expectedly, vaccination resulted in a less severe clinical presentation of SARS-CoV-2 infection, as reported by the participants.

The results suggest that the efficacy of the vaccination agents presently utilized by HCWs was acceptable with no significant difference in vaccine type. Participants receiving at least two doses of vaccines in this survey exceeded 90%, which is comparably higher than studies conducted in other countries.

Leprosy remains an important health problem worldwide. It is one of the oldest recorded diseases of humankind. In this study, we expanded the analysis of the geographic distribution of Mycobacterium leprae by investigating SNPs and rpoT genotypes in South Central Coast and Central Highlands clinical isolates, providing insights into the distribution and transmission of leprosy in Vietnam and in this geographic region.

27 clinical isolates from the patients, determined the genotypes of M. leprae by SNP and rpoT polymorphism. SNP genotyping was performed by PCR amplification and sequencing, rpoT genotyping by PCR amplification and electrophoresis.

All of 27 DNA samples (100%) were positive with RLEP TaqMan PCR (Ct value range is 18-32 on 3 replicates). SNP type 1 was identified in 15 isolates (56%), while SNP type 3 was detected in 12 samples (44%). SNP type 2 and type 4, were not detected. The 6-base repeat region of the rpoT gene was amplified by PCR and analyzed by 4% MetaPhor™ agarose gel electrophoresis. All isolates yielded amplification products of 91-bp, but not 97-bp.

This study showed that 56% of isolates belonged to type 1, 44% to type 3. In addition, all samples have the 3-copy hexamer genotype in the rpoT gene.

 Concomitant carriage of blaNDM-1 and plasmid mediated quinolone resistance determinants (PMQRs) by multi drug resistant (MDR) Klebsiella pneumoniae (K. pneumoniae) has increased globally, often related to their presence on transmissible plasmids. In this study, we hypothesized the presence of blaNDM-1 and PMQRs on a single conjugative plasmid that circulates among K. pneumoniae strains isolated from Assiut University Hospital.

 Twenty-two clinical MDR K. pneumoniae strains harboring both blaNDM-1 and PMQRs were genotyped using pulsed field gel electrophoresis. Horizontal transfer of blaNDM-1 and PMQRs was evaluated by conjugation and trans-conjugants were screened for the presence of both genes and integron by PCR. Trans-conjugant’s plasmid DNA bands were purified using agarose gel electrophoresis and different DNA bands were screened for blaNDM-1 and PMQRs. Plasmids carrying blaNDM-1 and PMQRs were typed by PCR based replicon typing.

 All MDR K. pneumoniae contained class 1 integron and belonged to 15 pulsotypes. BlaNDM-1 and PMQRs were co-transferred in each conjugation process. Multiple replicons (5-9 types) were detected in each trans-conjugant; with IncFIIK and IncFIB-KQ replicons being common among all trans-conjugants. Both blaNDM-1 and PMQRs were detected on a pKpQIL-like multi-replicon plasmid that was present in all K. pneumoniae strains.

 In view of these results, the presence of blaNDM-1 and PMQRs on pKpQIL-like plasmid that existed in multiple unrelated K. pneumoniae isolates is highly suggestive of the circulation of pKpQIL-like MDR plasmids in our hospitals. Moreover, carriage of integrons by the-circulating MDR plasmids increases the risk of dissemination of antimicrobial resistance among pathogens.

Group B Streptococcus (GBS) is one of the most important causes of neonatal diseases and postpartum fever. GBS infection can be transmitted from the infected mother to her baby during delivery. This bacterium is also involved in causing urinary tract infections and asymptomatic bacteriuria, pyelonephritis, cystitis and urethritis. In addition to capsule, Pilus is known as a virulence factor of GBS. The aim of this study was to evaluate the frequency of pilus islands and antibiotic resistance in GBS isolated from urine of pregnant women in Yazd, Iran.

In this cross-sectional study, 33 GBS samples isolated from the urine of pregnant women were studied by the multiplex polymerase chain reaction (PCR) method for the presence of pilus islands PI-1, PI-2a and PI-2b. Antibiotic resistance phenotype of tetracycline, penicillin, gentamicin, erythromycin, levofloxacin and clindamycin was determined by disk diffusion method. Data were analyzed using SPSS, version 16.

PI-1+PI-2a was the most frequent pilus island in the GBS isolates 28 (84.8%) and the frequency of PI-2b was 5 (15.2%). The frequency of PI-1+PI-2a was 50% in serotype III and 25%, 14.3%, 7.1% and 3.6% in serotypes Ia, II, Ib and V respectively (P=0.492). The sensitivity of all GBS isolates to penicillin was 93.9% and highest resistance to tetracycline (97%), clindamycin (24.2%) and erythromycin (21.2%).

Most of the GBS urine isolates examined carried the PI-1+PI-2a gene, which increases bacterial potency in colonization and resistance to the immune system. Penicillin was best choice for prevention.

In healthcare settings, hospital water and water-related devices can act as a reservoir for waterborne infections. Potable water, sinks, faucet aerators, showers, tub immersion, toilets, dialysis water, water baths, eyewash stations, and dental-unit water stations have all been linked to nosocomial outbreaks. This study aimed to determine the microbial profile and pattern of antibiotic resistance in the water supply of a tertiary care hospital in Uttarakhand.

This is a 1-year prospective study which was carried out by the Department of Microbiology and Immunology at Sri Mahant Indersh Hospital (SMIH), Dehradun. A total of 154 water samples were collected from the AC outlets, ventilators in the Intensive care unit (ICUs), Operation theatre (OTs), and High dependency unit (HDUs), scrub sta- tions, pantry, and blood bank, patient’s bathroom, private ward, septic ward, labour room, transplant unit, laboratory, scope rinse water, the dialysis unit and tank throughout the hospital, including tap water (pre and post flush [25%]), tap swabs (24%), drinking water (9%), AC outlets (13%), and other areas (3%).

30 of the 154 (19.5%) water samples tested were culture-positive. The most contaminated water samples were tap swabs (27%, n = 8/30). A total of nine organisms were isolated, of which the most predominant was Pseudomonas aeru- ginosa (40%; 12/30), followed by Legionella pneumophila (13%; 4/30), Acinetobacter baumanii (10%; 3/30), Klebsiella pneumoniae (10%; 3/30), Escherichia coli (7%; 2/30), Enterococcus faecalis (7%; 2/30), Aspergillus flavus (7%; 2/30), Stenotrophomonas (3%; 1/30), and Fusarium spp. (3%; 1/30). Gram-negative bacilli and non-lactose fermenting (GNB and NLF) showed a high rate of contamination, 53.3% (n = 16/30). P. aeruginosa showed resistance to gentamicin and amikacin (42%), imipenem (50%), levofloxacin (58%), and colistin (25%), while Acinetobacter baumanii showed resistance to genta- micin and amikacin (67%), minocycline (63%), and levofloxacin, imipenem and colistin (33%).

The study's findings show that a variety of microorganisms are contaminating hospital water supplies and can be a source of hospital-acquired infections. A suitable and robust surveillance program for hospital water supplies, as well as strict adherence to infection control practices, is strongly advised.

Bacterial causes of gastroenteritis include Salmonella, Shigella spp, diarrheagenic Esche- richia coli, Vibrio cholera and Campylobacter spp. Although infections caused by NTS (Non Typhoidal Salmonella) and Shigella are usually self-limiting, antibiotic treatment is prefered in severely ill or immunocompromised individuals. The main objective of the study was to find out the prevalence of Salmonella and Shigella among the stool samples received in Believers Church Medical College hospital and the antimicrobial susceptibility pattern of Salmonella spp. and Shigella spp.

A total of 805 stool samples collected from cases of diarrhea from January 2018 to December 2021 were processed in the laboratory. Standard bacteriological methods were used to isolate, identify, and determine the antimi- crobial susceptibility pattern of Salmonella and Shigella isolates using the disc diffusion method and interpreted according to CLSI.

A total of 100 (12.4%) samples yielded bacterial pathogens. Salmonella was isolated from 97 (12%) samples and Shigella from 3 (0.4%) samples. Salmonella enterica serovar Typhimurium was the predominant serotype, accounting for 53 (54.6%) isolates.

This study showed Salmonella enterica serovar Typhimurium as the predominant isolate causing diarrheal illness. The emergence of multidrug resistant phenotypes warrants the continuous monitoring of susceptibility trend of NTS in India.

Staphylococcus simulans secretes an antimicrobial compound called lysostaphin, which has bactericidal properties. It destroys staphylococci through the hydrolysis of peptidoglycan in the cell wall. Therefore, this unique property indicates the high ability of lysostaphin in the treatment of staphylococcal infections and is considered as an anti-staphylococcal agent.

Escherichia coli BL21 (DE3) competent cells were transformed with pET32a-lysostaphin clone and induced by isopropyl-β-D-thio-galactoside (IPTG). The recombinant protein was purified by affinity chromatography. Recombinant lysostaphin -A-based ointment was used for external wound healing in animal model. In vivo activity of oint- ment was evaluated by clinical evidences and cytological microscopic assessment.

Our results showed the recombinant protein was produced exactly. The results of checkerboard tests showed MIC, MBC and antibacterial activity test an acute reduction of cell viability during the use of lysostaphin, and SEM results ap- proved the intense wrecking effects of lysostaphin in combination on bacterial cells. Macroscopic findings and microscopic data showed that the recombinant lysostaphin ointment was effective on excisional wound healing.

Our findings proved that the recombinant lysostaphin ointment was effective on wound healing due to Staphy- lococcus aureus infection.

Staphylococcus aureus is responsible for the majority of food poisoning all around the world. Nasal carriers of S. aureus and foodstuffs need for handling are important sources and vehicles to transmit this pathogen to ready-to-eat foods. According to hygienic standards, confectioners should not be contaminated with S. aureus. This study aimed to detect nasal carriers and creamy pastries contaminated with enterotoxigenic S. aureus in confectioneries of Shiraz, Iran.

From the confectioneries of Shiraz city, 27 places in the north, south, center, west, and east areas were selected randomly then 100 creamy pastries samples and 117 nasal swabs were collected. Bacteriological and biochem- ical tests were performed to isolate S. aureus. The polymerase chain reaction (PCR) test was used to identify the virulence and enterotoxins genes of the S. aureus isolates. Agar disk diffusion was performed to find out the antibiotic resistance of the isolates.

Results revealed that 16.24 and 33 percent of workers and creamy pastries were contaminated with S. aureus respec- tively. Also, 100%, 37%, 58%, and 6% of nasal samples harbored femA, mecA, sea, and sec genes respectively. According to the results 97%, 70%, 54.5%, and 6% of creamy pastries isolates harbored femA, mecA, sea, and sec genes respectively. No isolate carried seb and sed genes. The results also showed that 41.5% of nasals and 5.5% of creamy pastry isolates har- bored both sea and sec genes. The sea was the most common enterotoxin gene observed in nasal and creamy pastries. The results of the antimicrobial resistance test showed that 68.42% of nasal and 48.48% of creamy pastry isolates were resistant to cefocxitn (FOX) respectively. Both nasal (89%) and creamy pastry (82%) isolates presented the highest resistance to pen- icillin (P) and the most sensitivity to trimethoprim-sulphamethoxazole (SXT) (94%). Most of the isolates were sensitive to erythromycin (E), aztreonam (AZM), tetracycline (TE), trimethoprim (TMP), and ciprofloxacin (CP). Isolates of S. aureus harboring multi-enterotoxin genes were resistant to more antibiotics than others.

The presence of enterotoxigenic S. aureus in the workers’ nasal samples and creamy pastries of Shiraz confec- tioneries was high which is a potential public health hazard.

Although the study on the bacteria residing in the mid-gut, salivary gland, and reproductive organs of insect vectors have drawn appeal to the host-pathogen interactions, we know comparatively less about microbiota that naturally exist in different mosquito organs within Iran.

In the current investigation, PCR assay by using 16S rRNA gene amplification and DNA sequenc- ing, in addition to the traditional culture-based approach utilized for the detection of cultivable bacterial assemblages in mid-gut and reproductive tracts of Culex quinquefasciatus.

The identified bacteria isolated from different tissues of 45 individuals were consisted of Achromobacter, Aero- monas, Arthrobacter, Asaia, Enterobacter, Gluconobacter, Klebsiella, Lysinibacillus, Micrococcus, Psuedomonas and Serra- tia. The results showed that Proteobacteria was the most prevalent phylum in both genders' mid-gut and reproductive tracts, and Asaia was the most common bacteria that originated in adult females and males’ tissues.

These outcomes recommend that the discovered microbiome may span through Cx. quinquefasciatus popula- tions. This data can be utilized to interfere with the transmission of pathogens and design new strategies for the control of mosquito-borne diseases.

The use of probiotics as an alternative to antibiotics in poultry diets has attracted a lot of in- terest recently. In this context, the determination of probiotic characteristics was evaluated on several isolates obtained from Iranian poultry’s gut.

Probiotic characteristics such as hemolysis activity, acid, bile, gastric juice tolerate, in vitro ad- hesion assay, cell surface properties (hydrophobicity, auto-aggregation and co-aggregation) and antibiotic susceptibility test were evaluated. Finally, selected isolates identified molecularly after temperature-salt tolerance and extracellular enzyme activity (amylase, protease and cellulose).

Out of 362 strains isolated from native poultry in three geographical regions of Iran, nine strains (belong to Bacillus sp., Enterococcus sp., Pediococcus sp., Lactobacillus sp., Kluyveromyces sp.) showed resistance against gastrointestinal physiological conditions, desirable surface properties, ability to adhere to epithelial intestine cell line and antibiotic suscep- tibility. Also, these strains were discovered to be temperature-salt tolerant but, only a small number of them were able to produce hydrolase enzymes.

According to the results, the selected strains can be introduced as native probiotic candidates for utilization in novel poultry feeds.

Sustainability in agricultural systems without compromising the environmental quality and conservation is one of the major concerns of today’s world. The excessive use of agrochemicals is posing serious threats to the environment. Therefore identification of efficient plant growth promoting (PGP) bacteria as an alternative to chemically synthesized fertilizers is of great interest.

In the present investigation, forest soil samples collected were used for isolation of efficient plant growth promoting bacteria.

Total of 14 bacteria were isolated, and tested for various PGP properties. Out of the 14 isolates, four isolates la- belled as BKOU-1, BKOU-8, BKOU-13 and BKOU-14 showed significant plant growth promoting traits, hydrolytic enzyme production and effectively restricted the mycelial development of phyto-pathogenic fungi (Fusarium oxysporum and Mac- rophomina phaseolina). 16 S rRNA gene sequences of the bacterial isolates BKOU-1, BKOU-8, BKOU-13 and BKOU-14 were found to have maximum identity with Bacillus aerius, Bacillus infantis, Alcaligenes faecalis and Klebsiella Oxytoca respectively. All four bacterial isolates nucleotide sequences were submitted to GenBank and NCBI accession numbers were generated as follows: OL721916, OL721918, OL721919 and OL721926.

According to the findings of the study, these PGPR could be employed as biofertilizers/ biopesticides to boost crop yield of different crops in sustainable manner.

Heavy metals pollution is one of the most important concerns in the world. Selenium is one of the most important elements for the life, but if the absorption of this element in cells increases, it acts as a toxic element.

In this study, bacterial isolates were screened and isolated from selenium-contaminated soil and water. Twenty -five out of 42 isolates were able to reduce Selenite. Also, the response surface method (RSM) was used to evaluate and optimize the biological reduction of selenite by Selena 3. Factors of bacterial inoculation percentage, time, and amount of selenium oxyanion salt concentration were studied at five levels of -α, -1, 0, +1, and +α.

Bacillus sp. Selena 3 was able to reduce 80 mM sodium selenite in less than 4 hours compared to other bacteri- al isolates. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of sodium selenite Bacillus sp. Selena 3 was reported as 160 and 320 mM, respectively. The results showed that with increasing duration, the percentage of selenite reduction by bacteria increases and the percentage of bacterial inoculation does not have much effect on its reduction.

Due to the ability of Bacillus sp. Selena 3 for rapid reduction in significant concentration of selenium oxyanion (SeO 2-), this bacterium can be used as an efficient candidate in removing selenite from the environment.

Adhesion of microorganisms on facemask surfaces is a major problem that produces contam- ination of the mask wearer either by inhalation or by direct contact. Generally, physicochemical properties of the material and the microorganism are responsible for this adhesion and are also reported to influence the filtration efficiency of face- masks. However, theses surface proprieties and their effect on particles attachment on facemask materials remain poorly documented. The purpose of this study was to investigate the physicochemical properties of seven facemasks and evaluate the influence of these characteristics on the adhesion of Sataphylococcus aureus.

Physicochemical properties is done by contact angle method and scanning electron microscopy while theoretical adhesion of S. aureus is done according to XDLVO approach.

The obtained results showed that all masks have a hydrophobic character. The electron donor and electron acceptor parameters change depending on each mask. Chemical analysis demonstrates the presence of two chemical elements (car- bon and oxygen). Predictive adhesion demonstrate that S. aureus has an attractive behavior towards the masks used but the potential of adhesion is not the same.

Such information is valuable to understand attachment of biological particles and to contribute in the inhibition of this attachment.

Intestinal leakage commonly occurs in severe dengue infection with zonulin as a biomarker. The aim of this study was to determine the effects of NS1 on liver weight, zonulin expression and serum zonulin levels.

This laboratory experiment used 18 ddY mice, which were randomly divided into control (C), PBS (T1), and PBS + NS1 (T2) groups. Mice in the T1 and T2 groups were intravenously injected with 500 μl PBS only and 50 μg NS1 respectively. Mice blood samples were collected before and after three-day treatment for measurement of zonulin level. The fresh liver was weighted directly and were then used for immunostaining.

The C group had lower wet liver weight compared to the T groups (p=0.001). Increased expression of liver zonu- lin was found in the T2 group, significant different from the C (p=0.014) and T1 groups (p=0.020). After treatment, serum zonulin levels in the T1 group was higher than that of the T1 group before treatment (p=0.035) but not in control (p=0.753) and T2 groups (p=0.869).

Administration of 50 μg NS 1 increases wet liver weight and zonulin expression in hepatocytes, but did not increase serum zonulin levels in ddY mice.

Vulvovaginal candidiasis (VVC) is one of the most frequent reasons for gynecological consul- tations. Candida albicans is responsible in the majority of cases. Lately, VVC caused by non-albicans Candida spp. (NAC), which are resistant to routinely used antifungals, is on the rise. This study was designed to determine the prevalence of Candida in patients suffering from vaginitis and to assess the predisposing factors along with identification of Candida species and evaluation of their susceptibility profile.

High vaginal swabs were collected from 225 women. Sample processing consisted of Gram stain and culture onto Sabouraud’s dextrose agar and HiChrom Candida Differential agar. Isolates were identified and speciated using VITEK2 Compact System. Susceptibility testing was done using VITEK2 AST-Y S08 cards and disc diffusion.

Candida spp. were isolated from 94 (41.8%) of the cases. C. albicans was the predominant species (71.6%) fol- lowed by other NAC spp. (28.4%). Pregnancy and diabetes were the most frequently implicated risk factors (67.1% and 44.4%). High resistance was observed in NAC spp. as opposed to C. albicans to all antifungal agents tested.

Empirical therapy with routinely used antifungals can be initiated for C. albicans. In the case of NAC spp., identification should be followed by susceptibility testing.

Previous researchers showed the antimicrobial ability of ionic liquids (ILs) on different infec- tive agents. ILs can dissolve organic components, especially DNA molecules. Among synthesized eight binary ILs mixtures, we have chosen ([Met-HCl] [PyS]) IL for determining the antifungal ability of IL against Candida albicans cells.

Well diffusion assay, chrome agar and Germ tube tests were used to detect the Candida samples. PCR, real-time-PCR, and flow cytometry tests were performed to determine the IL's rate of toxic ability.

Well diffusion assay revealed the diameters of the growth inhibition zones were the largest in IL with methionine and Proline amino acids. Minimum inhibitory concentration (MIC) and the Minimum fungicidal concentration (MFC) tests showed that they inhibited the growth of the C. albicans at a range from 250 μg/ml for sensitivity and 400 μg/ml for resis- tance, MIC average of all samples were 341.62 ± 4.153 μg/ml. IL reduced the expression of CDR1 and CDR2 the genes encoded by the major protein of ABC system transporter by 2.1 (P= 0.009) and 1.2 fold (P= 0.693), revealed by PCR and real time-PCR. In the flow cytometry test, there were increasing dead cells after treating with the ([Met-HCl] [PyS]) even in the most resistant strain.

The novel IL was effective against the most clinical and standard C. albicans.