Iranian Journal of Microbiology
Volume:11 Issue: 5, Oct 2019

Contact lenses (CLs) are increasingly being used for cosmetic or therapeutic purposes. Lack of compliance and poor hygiene towards lens care is strongly associated with microbial contamination and has been proved to result in eye infections. The present study was done to compare the microbial flora between symptomatic and asymptomatic contact lens users. The study also attempts to analyze the contact lens hygiene practices of CL users.

Six samples each were collected from both the eyes, CLs and lens cases of 40 CL users (n=240) divided into two groups based on symptoms present as- asymptomatic CL users and symptomatic CL users. Organisms were identified using standard microbiological techniques.

The proportion GNB obtained in symptomatic CL users was significantly higher when compared to asymptomatic CL users (p-value= <0.003). In 56.2% eyes, the microbial flora of conjunctiva was similar to either the contact lens isolate/storage case. Enterococcal microbial keratitis was seen in one case.

There was significant microbial contamination present in CL users despite compliance to contact lens hygiene practices. There were a significant number of bacteria (p-value <0.001) present which were resistant to ampicillin, amoxicillin-clavulanate, and cefotaxime in both the groups.

Oral mucosal infections are an important type of oral lesions. The aim of this study was to determine the epidemiology of oral mucosal infectious lesions in patients who referred to Oral Medicine Department of Shiraz Dental School, Iran during 11 years.

In this cross sectional study, records of all patients who referred to Oral Medicine Department of Shiraz Dental School from September 2007 to January 2018 were assessed and those data sheets which their definitive diagnosis were a kind of oral mucosal infectious lesion were recorded. Pearson Chi- square test was used for statistical analysis. Level of significance was considered as P value < 0.05.

Overall prevalence of oral mucosal infectious lesions was 9.47%. Generally, mean age of patients was 42.92 ± 18.84 and most of them were female. Most common type of infectious lesions was fungal infections, but viral and bacterial infections were less common. Among fungal infections, most lesions were candidiasis and only 3 cases were diagnosed as deep fungal infection. HSV infection was the second common oral infectious lesion. There was a significant relation between infectious lesion and systemic disease or medication use (P=0.000).

This study is the first epidemiologic study in Iran, concerning oral mucosal infectious lesions. Total of 9.47% of oral lesions were infective, candidiasis and HSV lesions were the most common oral mucosal infective disease, which were more prevalent amongst female, middle age people and patients with systemic disease.

Brucellosis is a widespread zoonotic disease with a high prevalence in both animals and humans. The present study was aimed to evaluate the susceptibility of Brucella strains isolated from human clinical specimens against commonly used antimicrobial agents.

A total of 360 blood specimens were collected during 2016-2018 and subjected to culture and Brucella spp. identification. The classical biotyping for Brucella isolates was performed according to Alton and coworker's guidelines. Antimicrobials susceptibility test carried out using disk diffusion and minimal inhibitory concentration (MIC) methods.

In this study, sixty B. melitensis strains were isolated from blood samples (16%) and all them belonged to biovar 1. Majority of the tested antibacterial agents, excepting ampicillin-sulbactam had an effective activity against B. melitensis isolates in E-test (MIC) and disk diffusion method. Moreover, probable resistance to rifampin and ampicillin-sulbactam were observed in 60 (100%), 1 (1.7%), 11 (18.4%) and 2 (3.4%) isolates, respectively.

Our data suggest that the efficacy of commonly used antibiotics for brucellosis treatment should be regularly monitored. In conclusion, appropriate precaution should be exercised in the context of antibiotic administration to prevent future antibiotic resistance.

In recent years, reports of Acinetobacter strains resistant to all known antibiotics have caused a great concern in medical communities. Overexpression of efflux pumps is one of the major causes of resistance in bacteria. The aim of this study was to investigate the role of efflux pumps in conferring resistance to imipenem in clinically important Acinetobacter spp; Acinetobacter baumannii and Acinetobacter lwoffii.

A total number of 46 clinical Acinetobacter isolates, including 33 A. baumannii and 13 A. lwoffii isolates, previously collected from Shahid Kamyab and Ghaem hospitals of Mashhad, Iran were used in this study. Imipenem susceptibility testing was carried out by the disc diffusion method. Imipenem minimum inhibitory concentration (MIC) for resistant Acinetobacter isolates were determined both in the presence and absence of the efflux pumps inhibitor, carbonyl cyanide 3-chlorophenylhydrazone (CCCP).

Resistance to imipenem was observed in 38 isolates including 30 A. baumannii and 8 A. lwoffii isolates. Experiments in the presence of CCCP showed a 2 to 16384 fold reduction in imipenem MICs in 14 A. baumannii and 2 A. lwoffii isolates.

The results obtained showed high levels of resistance to imipenem and contribution of efflux pumps in conferring resistance in both Acinetobacter species in this study. Moreover, imipenem efflux mediated resistance highlights the importance of this mechanism not only in A. baumannii but also in non-baumannii Acinetobacter Spp. which have been neglected in antibiotic resistance studies.

Leptospirosis, an infection caused by pathogenic leptospires, is associated with insufficient sanitation and poverty. Leptospira is transmitted through contact with contaminated urine of reservoir animals. The primary objective of this study was to clone and sequence the ompL37 gene present in local and vaccine serovars.

A total of 16 Leptospira interrogans serovars were cultured in EMJH liquid medium. After growing, genomic DNA was extracted using phenol-chloroform method. Primer pair was synthesized to amplify the 996 bp ompL37 sequence. The amplified ompL37 gene was cloned into pTZ57R/T vector. The sequences obtained from this study were compared with an only recorded sequence in the Genbank by the Meg Align software.

PCR products showed an amplified 996bp ompL37 gene product belonging to pathogenic serovars, while no ompL37 products were amplified in non-pathogenic serovars. Sequences comparison tests from 16 native serotypes examined in this study displayed a similarity range of 84% to 99.5% among serovars used. The results showed that two serotypes of L. interrogans including Serjoehardjo (RTCC2810 and RTCC2821) had the highest identity up to 95.5%. Two serovars of L. interrogans including Pomona (RTCC2822) and Icterohaemorrhagiae (RTCC2823) had the lowest identity about 84%.

As the results showed, ompL37, present on the surface of such bacteria, showed a conserved sequence. ompL37, as a key role in cell adhesion and pathogenicity, can be used for designing diagnostic tests and vaccines. Furthermore, sequencing of various sites in ompL37 gene, including binding sites and immunogenic epitopes, can be valuable alternatives for future studies.

Several LAB species were evaluated and characterized for potential probiotic use. Besides the antimicrobial activity, probiotics showed recently a capacity to prevent and to alleviate inflammatory and chronic diseases. Immunomodulation effect is one of the modes of actions of such probiotics, called immunobiotics, which can be used in several chronic diseases such as Inflammatory Bowel Diseases (IBD). The aim of this study was to isolate, identify and characterize lactobacilli strains from healthy baby’s feces in order to select some strains with potential immunobiotic application especially strains which can stimulate anti-inflammatory responses.

Forty-two LAB strains were isolated and identified by the MALDI-TOF / MS technique. In addition, strains were subjected to several assessments such as antimicrobial activity, the capacity to form biofilm in polystyrene microplate and immunomodulation activity in a PBMC model.

Results showed that the majority of strains (90.4%) were identified as Lactobacillus. However, among these, only 39.4% of lactobacilli strains were not identified at the species level. All isolated lactobacilli strains showed an anti-inflammatory effect. Moreover, 7 strains were considered as good probiotic candidates based on their characteristics such as their antibacterial activities, formation of the strongest biofilm and their ability to stimulate an anti-inflammatory response in PBMCs model.

Two strains (Lactobacillus spp S14 and Lactobacillus spp S49) which showed the best immunobiotic characteristics, could be selected and evaluated more deeply in vivo model as well as in human clinical study to ensure their effectiveness in inflammatory diseases such as IBD.

Gut microbiota influences our health via multiple mechanisms. Microbiota produced Short Chain Fatty Acid (SCFA) as an energy to maintain gut ecosystem and physiology. Dysbiosis is correlated with SCFA imbalance which in turn resulted in physiological abnormalities in the intestine, such as functional constipation.

Randomized Double-Blind Controlled Trial (RCT) was conducted on women with functional constipation (n=37) in the community of Jakarta and profile of SCFA was assessed by using GC-MS from the stool after 21 days supplementation of fermented milk (placebo and probiotic).

Probiotic supplementation significantly influenced acetate titer (p=0,032) marginally significant for propionate and butyrate (p=0.063 and p=0.068, respectively) and the respondent with increasing SCFA’s metabolite are higher in probiotic group compared to the respondents in placebo group. Acetate is the highest SCFA titer found in faeces samples of women with functional constipation.

Probiotic Lactobacillus plantarum IS 10506 supplementation influenced all the SCFA parameter (acetate, propionate and butyrate).

Antimicrobial peptides produced by lactic acid bacteria have gained enormous attention owing to their health benefits. This study aimed to isolate, purify and characterize the antibacterial protein produced by autochthonous Lactobacillus casei TA0021 strain.

The antagonistic activity of L. casei TA0021 against a number of pathogenic bacteria was tested by agar well diffusion assay. The antimicrobial agent in the neutralized supernatant fluids was subjected to the action of proteolytic enzymes, catalase, lipase and lysozyme, and their tolerance to variable pH and temperature was estimated. The proteinaceous antagonistic compound was precipitated by 60% w/v ammonium sulphate, desalted and subjected to cation exchange and gel filtration chromatography. Approximate molecular weight of Lactocin was determined by SDS-PAGE and non-denaturing gel electrophoresis. Hemoglobin release assay and cytotoxicity effect of Lactocin TA0021 was determined. The results were statistically analyzed.

The antagonistic agent active against Salmonella Typhimurium and Shigella flexneri appeared resistant to catalase and lipase treatments, while sensitive to the tested proteolytic enzymes. Lactocin TA0021 resisted acidic pH values of 3.0, while alkaline pH values of ˃9 completely destroyed the activity. The antibacterial peptide was approximately 68 KDa and heat labile as lost its activity at 100°C after 5 minutes. The bacteriocin was non-toxic to MRC-5 cell lines and non-hemolytic. Purification method lead to increase in antibacterial activity while, subsequent decrease in recovery and yield was observed with increasing purification fold.

The purified antimicrobial protein from L. casei TA0021 might be used for application in medicinal and food products.

An experiment was designed to determine the effect of using lactic acid bacteria as alternative antibiotic growth promoters on external and internal quality of egg’s Coturnix coturnix japonica.

Coturnix coturnix japonica (n=240, 14 weeks of age) were randomly distributed into six treatment groups. The treatments were P0 (free antibiotic feed), P1 (free antibiotic feed with 1 gram antibiotic growth promoters (AGP)/100kg feed), P2 (free antibiotic feed with 5 gram probiotic/100kg feed), P3 (free antibiotic feed with 10 grams probiotic/100kg feed), P4 (free antibiotic feed with 5 gram probiotic/200L drinking water), and P5 (free antibiotic feed with 10 gram probiotic/200L drinking water). Probiotic contained Lactobacillus casei (L. casei) and Lactobacillus rhamnosus (L. rhamnosus) culture (1.2 x 108 CFU/gram). To assess the quality parameters, twenty eggs were randomly collected from each treatment at the end of the experimental period, and the data were analysed using one way Anova.

Results of the external quality indicated that egg’s weight, length, and width, along with the shell weight and thickness were significantly different (P<0.05) after treatment. Likewise, the results of internal egg quality indicated that yolk color, height, width, and length, together with the albumen height, width, length, index and haugh unit were significantly different (P <0.05) after treatment.

It was concluded from this research that dietary supplementation with probiotic which contains L. casei and L. rhamnosus could be used in laying Japanese quail with benefit on external and internal egg quality.

Inflammation in the intestine causes diarrhea due to an increased release of pro-inflammatory cytokines such as TNF-α, IL-1, and IL-6. These are triggered by the exposure of E. coli-LPS to epithelial cells of the intestinal mucosa as well as low concentration of zinc in plasma such as in infants or children who are experiencing diarrhea. This paper aims to determine the effects of zinc supplementation on pro-inflammatory cytokines (TNF-α, IL-1 and IL-6) in mice with E. coli-LPS-induced diarrhea.

This study used a controlled trial experimental design in the laboratory. A sample size of 20 mice were randomly divided into 4 groups: 1) Control group was given standard foods, 2) Trial group was given E. coli-LPS 2.5 mg/kg/oral once on day1, 3) Prevention group was given E. coli-LPS + 30 mg/kg/oral of zinc once daily for 12 days, 4) Therapeutic group was given E. coli-LPS, and were then given 30 mg/kg/oral of zinc once daily for 12 days if diarrhea occurred. Blood samples of mice were taken through the orbital sinus on the 0, 5th, 10th hour, and on the 4th, 8th and 12th days.

Positive effects of zinc supplementation on levels of pro-inflammatory cytokines were observed, in which the higher levels of zinc were present, the lower levels of pro-inflammatory cytokines, especially TNF-α were observed. However, there was an increase of IL-1 and IL-6 levels on the 8th day in the prevention and therapeutic groups.

Oral zinc supplementation had a significant positive effect on the levels of pro-inflammatory cytokines. Where there were higher levels of zinc, lower levels of pro-inflammatory cytokines TNF-α were present.

Iron and zinc are two essential micro-nutrients for plant growth and development. Therefore, isolation of siderophores-producing and zinc-solubilizing rhizobacteria involved in bio-availability of these elements is of great interest.

In this study, soil samples collected from slightly alkaline soil types were screened for high levels of siderophore secretion and zinc solubilization.

Among positive colonies, three isolates, named F21A, F37 and F38, were able to secrete siderophore at high levels, ranged between 200 and 300 µM/liter. A close association was observed between siderophore production capability and growth rate as an indicator of active metabolism. Siderophore production was closely correlated with the level of zinc ion released into the medium as well. All three siderophore producing isolates were able to withstand temperature as high as 37°C, high concentration of NaCl (up to 2.5%) and a wide range of initial pH from 6 to 9 while hydrolyzing Zn compounds actively. One of the isolates, F21A, tolerated the presence of 200 mgl-1 of zinc. Biochemical and molecular characteristics are indicative that these isolates are Pseudomonas japonica. As experienced in a greenhouse experiment, inoculation with the F21A and F37 isolates significantly increase the plants height, fresh and dry weight of corn with compared to control.

These findings demonstrated that the potential of P. japonica strains as plants growth promoting rhizobacteria (PGPR) in iron and zinc deficient soils.

The surrogate marker (s) of cure and protection in intracellular pathogens is not yet well defined. The aim of this study was to compare the cytokine profile using whole blood cells (WBC) vs. peripheral blood mononuclear cells (PBMC) in healthy and cutaneous leishmaniasis (CL) volunteers.

In this study, WBC and PBMC of the volunteers with history of CL (HCL), Active lesion (ACL) and healthy volunteers were collected. The WBC and PBMC were cultured and stimulated with either PHA or soluble Leishmania antigens (SLA), after 72 hours, the supernatants were collected and the levels of IFN-γ, IL-5 and IL-10 were titrated using ELISA method.

The mean ± SD of cytokines using WBC and PBMC in cutaneous leishmaniasis volunteers stimulated with phytohemagglutin (PHA) or SLA are as follow, PHA, IFN-γ=2295±995 vs. 2339±1115, IL-10=853±309 vs. 1330±966, and IL-5=299±136 vs. 352+156, SLA, IFN-γ, 931±824 vs. 825±532, IL-10, 233±78 vs. 408±381, and IL-5, 185±59 vs. 217±76, respectively. There was no significant difference between the IFN-γ, IL-5 and IL-10 levels using WBC vs. PBMC. There was a strong correlation between the cytokine profiles using WBC and PBMC in cutaneous leishmaniasis volunteers.

There was no significant difference between IFN-γ, IL-10, IL-5 levels in whole blood and PBMC of volunteers with active lesion or history of CL. Whole-blood culture which is easier, cheaper and more convenient could be used instead of PBMC to evaluate the cytokine profile in field conditions.

This prospective case-control study was conducted to evaluate abnormal serum protein electrophoresis (SPEP) patterns in patients living with human immunodeficiency virus (HIV) and its relation with disease severity markers and anti-retroviral treatment status.

Thirty-seven HIV-positive patients and 24 healthy individuals were evaluated in the course of this study. The healthy HIV-negative individuals were selected as control group. Pregnant women, patients with malignancies, children, hepatitis B- and/or C-positive patients, those with a history of an autoimmune disease, or previous corticosteroid administration were excluded. SPEP—which detects serum levels of albumin, total protein, gammaglobulin—, CD4+ T-cell counts, viral load, and antiretroviral treatment status were assessed. Data were analyzed by SPSS™ software.

Twelve patients (32 percent) demonstrated polyclonal gammopathy on SPEP, while only 1 (4 percent) healthy individual had the same pattern (P-value = 0.007). No statistically significant connection between SPEP patterns and antiretroviral treatment status was observed (P-value > 0.05). Interestingly no statistically significant relationship between CD4+ T-cell counts and polyclonal gammopathy was discerned. No statistically significant difference was observed between the two groups with regards to serum albumin and total protein levels. The serum albumin to total protein percentage, serum gamma globulin to total protein percentage, and serum albumin to globulin ratio was compared between the groups and a statistically significant difference was observed.

Polyclonal gammopathy on SPEP is common among HIV-infected patients. Moreover, the SPEP patterns cannot be used as an indication of a patient’s negative or positive response to treatment.