جستجوی مقالات مرتبط با کلیدواژه « microbiology » در نشریات گروه « پزشکی »

It is worthwhile to note that, some probiotics such as Lactobacilli and Bifidobacteria isolated from dairy products have significant therapeutic effects against cancer cells. Here, we evaluated anti-proliferation and the apoptotic effects of isolated Lactobacillus fermentum Ab.RS22 from traditional dairy products on the HeLa cervical cancer cells in vitro. The viability of treated HeLa cells with supernatant of Lactobacillus in 0.5, 0.75, 1, 1.5, and 2 ng/ml concentrations, and IC50 values were detected by tetrazolium bromide. The L. fermentum Ab.RS22-induced cell death by flow cytometry was confirmed through evaluation of the expression of caspase-3, P53, PTEN, and AKT genes by quantitative reverse transcription-polymerase chain reactions (qRT-PCR). Most cytotoxicity effects of Lactobacillus on HeLa cells were detected in 2 ng/ml at 24 hr (P<0.01); also, the IC50 value was measured as 1.5 ng/ml. The findings of the flow cytometry assay showed that L. fermentum Ab.RS22 in 1.5 ng/ml concentration at 24 hr increased the percentage of both apoptosis and necrosis cells. Lactobacillus-induced cell death was verified through results of Real-time PCR; where expression of caspase-3, P53, and PTEN genes was increased (P<0.01), and also expression of AKT gene (anti-apoptotic) was decreased (P<0.05).  Our findings showed that L. fermentum Ab.RS22 could dose-dependently inhibit the proliferation of the HeLa cells. Its apoptotic effect was confirmed via modulating PTEN/p53/Akt gene expression and activation of the caspase-3 mediated apoptosis pathway. Therefore, L. fermentum Ab.RS22 can be considered a valuable anticancer candidate against cervical cancer progression in subsequent studies.

Today, the nanotechnology science is wide and it has entered nearly all scientific fields. One of the most important applications of nanotechnology is in medicine, especially in diagnosis of microbes (such as bacteria, fungi and viruses) and treatment of the infections caused by them. Yearly, the microbial infections lead to many medical problems such as increased duration of treatment, increased expenses of treatment, drag resistances, and even increased mortality. Since many years ago, antibiotics have been used in treatment of various infections, but unfortunately, their side effects as well as the resistance to them have always been the key problems. Thus, selection of the most suitable detection methods as well as the most appropriate treatment options for various microbial infections may reduce the crisis. It seems that nanotechnology approaches may efficiently help to diagnose many different microbial infections as well as to combat them, particularly the resistant ones, with no side effects currently caused by the traditional antibiotics.

The demand for an ideal root canal filling material in primary teeth with maximum antibacterial properties keeps escalating to improve the success rate of root canal treatment in primary teeth. Hence, the present study was conducted to determine the antimicrobial efficacy of the different concentrations of a novel root canal filling material.

An in vitro study was designed to compare the antimicrobial efficacy of different concentrations of the novel obturating material for primary teeth. Different concentrations of the novel obturating material were prepared using calcium hydroxide, zinc oxide cement, and metronidazole and were tested for its antimicrobial efficacy against Streptococcus mutans and Enterococcus faecalis using Mueller–Hinton Agar for 24 h at 37°C. The zone of inhibition was measured in millimeters after 24 h. The values were entered into a Microsoft Excel spreadsheet and subjected to statistical analysis. Descriptive statistics were used for data summarization and presentation. Friedman test and Kruskal–Wallis test were used to compare the different concentrations of the novel obturating materials against S.mutans and E.faecalis. P < 0.05 was considered to be significant.

Against S. mutans at 1% concentration, the zone of inhibition was statistically greater at 50 μl and at 2% and 3%, the zone of inhibition was greater at 100 μl. Similarly, against E. faecalis, the zone of inhibition was statistically greater at 100 μl at 2% and no significant difference was noted at 1% and 3%. Comparison between the groups at 25, 50, and 100 μl shows no significant difference against S. mutans between 1%, 2%, and 3% of 60–40 concentration. However, 3% 60–40 concentration at 50 μl shows significantly increased zone of inhibition against E. faecalis.

Two percentage metronidazole at 60–40 (calcium hydroxide–zinc oxide) concentration of the novel obturating material at 100 μl has better antibacterial properties against both S.mutans and E. faecalis.

Pietro Alano (26 May 1959) is Principal Investigator at Istituto Superiore di Sanità (ISS), Rome, Italy. After his Ph.D. (University of Milan, 1986) on the bacteriophage-E. coli interplay he entered molecular parasitology (Woods Hole course Biology of Parasitism, 1986; University of Edinburgh, 1987-1991) and joined ISS in 1991. Over the past 30 years Pietro’s team has investigated genetics, cell biology and development of the human malaria parasite Plasmodium falciparum and human and mosquito host-parasite interactions. This work, described in over 90 publications, generated ‘omics’ datasets, molecular tools and transgenic lines recently used in anti-parasite transmission drug discovery and development of innovative P. falciparum diagnostics tools. What comes below is an interview with Pietro Alano (PA) conducted by Mostafa Pourhaji (MP).

Pietro Alano (26 May 1959) is Principal Investigator at Istituto Superiore di Sanità (ISS), Rome, Italy. After his Ph.D. (University of Milan, 1986) on the bacteriophage-E. coli interplay he entered molecular parasitology (Woods Hole course Biology of Parasitism, 1986; University of Edinburgh, 1987-1991) and joined ISS in 1991. Over the past 30 years Pietro’s team has investigated genetics, cell biology and development of the human malaria parasite Plasmodium falciparum and human and mosquito host-parasite interactions. This work, described in over 90 publications, generated ‘omics’ datasets, molecular tools and transgenic lines recently used in anti-parasite transmission drug discovery and development of innovative P. falciparum diagnostics tools. What comes below is an interview with Pietro Alano (PA) conducted by Mostafa Pourhaji (MP).

Drowning and near-drowning are the consequences of recreational activities and natural disasters. The purpose of this study was to review the microbiology literature on drowning and near-drowning and to understand its applications in the diagnosis and treatment of these injuries and diseases.

This study is the result of a short review on publications extracted by searching in scientific database s including Google Scholar, PubMed and Semantic Scholar in the period from 1961 to 2021, usingthe keywords "Microbiology" and "Drowning" or "Near-Drowning".

A search in scientific databases revealed 184 articles related to "drowning" and "microbiology" and 84 articles related to "near-drowning" and "microbiology", of which 65 and 28 articles have been published in the last twenty years, respectively. Of these, 43 articles were used for this study. Regarding the microbiology of drowning and near-drowning, no study was conducted in the Islamic Republic of Iran in this field. The findings of the present study showed that:•Near-drowning in its victims causes physical and mental injuries, and invasive polymicrobial and fungal pneumonia, brain abscesses, and sepsis.•They are mainly associated with numerous bacterial agents e.g. Aeromonas spp., Nocardia spp., Vibrio spp., Photobacteriumspp., Burkholderiapseudomallei, Pseudomonas spp.,Plesiomonas shigelloides, and Shewanella spp. and Fungal and Protozoan pathogens are limited to Aspergillus spp., Scedosporium apiospermum,and Rhizopus spp., and Cryptosporidium parvum (rare), respectively.•If bacterial, fungal, and protozoa infections are not properly diagnosed and treated in drowning victims, they can lead to death in intensive care units and even long after discharge from the hospital.•Deaths from drowningand near-drowning are candidates for organ transplants, especially lung, bone, liver, and heart.•Clinical, environmental, forensic, and eco-microbio-epidemilogy studies in pre-and post-mortem drowning victims are being developed using cultured-basedand molecular methods such as PCR, LAMP, NGS, and Metagenomics, etc. to determine the drowning microbiome pattern.

Several cases of infections and diseases caused by drowning and near-drowning have been reported among the victims of recreational activities and natural disasters in different countries. Therefore,eco-microbio-epidemiological study of drownings in our country, where there isan average of 1,200 annual drownings on the north and south coasts and inland waters is essential. Even predicting tsunami and destructive storms on the shores of the Caspian Sea and the Oman Sea are very important indetermining the microbiome pattern of natural aquatic areas and the role of microbes in diseases and complications caused by drowning. Finally, a national protocol should be developed for microbial monitoring of drowning victims from the scene of water accidents to the hospital bed and on the autopsy table.

Dr. Abolghasem Bahrami was among the generation of Iranian scientists in the early twentieth century who gained most of their knowledge through resources available inside the country. Educated at Dar-ul-Funun Medical School, he was a physician with a great talent in learning, especially self-teaching natural sciences and European languages. He joined the Pasteur Institute of Iran (IPI) at the early days of its foundation and became an integral contributor to this institution during the first twenty-five years of its mission. One of his first assignments at IPI was to help initiating an anti-rabies department by bringing back the rabies vaccine and its manufacturing equipment from Institut Pasteur of Paris. During his IPI years, aside from managerial tasks, he actively participated in upgrading the medical treatments and protocols used for controlling many infectious diseases. He functioned twice as the provisional director of IPI (1925-1926 and 1937-1946) and is considered as the first Iranian director of the Institute. Meanwhile, Dr. Bahrami was a significant contributor to the public health system and assumed several responsibilities such as Chief Quarantine Medical Officer, Chief of Public Health, and the Head of Public Health Administration, in order to improve public health planning throughout the country.

With the onset of the coronavirus disease 2019 (COVID-19) pandemic in December 2019, healthcare systems faced an unprecedented challenge. Medical and paramedical students are the front-line warriors in this combat.

This study aimed to assess COVID-19 knowledge, attitudes, and practice among the students of Birjand University of Medical Sciences, Iran, in 2020.

This cross-sectional analytical study was carried out on 329 students who passed the microbiology course from October 2020 to March 2021. The data collection tool was a researcher-made questionnaire consisting of four sections: demographic data, COVID-19-related knowledge, attitudes towards COVID-19, and participants’ practice. Finally, statistical analysis was performed in SPSS software version 19, and a significance level of 0.05 was considered in all tests.

A total of 329 medical, dentistry, pharmacy, and laboratory sciences students participated in this study. The mean score of COVID-19 knowledge was 10.26 ± 1.21 (out of 12). Among the participants, 103 (31.3%) individuals expressed being in crowded places in recent days, and 324 (98.5%) of them confirmed wearing masks. More than half of the students had positive attitudes towards COVID-19 control. The average knowledge was higher in females and medical and laboratory sciences students (P = 0.008). Also, the students’ knowledge was inversely related to their practice of wearing a mask (P = 0.015).

While students had a high level of COVID-19 knowledge, they had some misconceptions that should be included in educational programs. Students of medical sciences should be responsible for preventive behaviors and strive to be good role models for others.

Objectives Infection control is one of the most important aspects of dentistry. Since intraoral radiographic films are directly in contact with the oral environment, microbial contamination may transmit infectious diseases. The purpose of this study was to investigate the frequency of microbial contamination of intraoral radiographic films and compare the probable microbial contamination of two intraoral radiographic film brands available in the Iranian market. Methods in this in vitro, experimental study, 900 radiographic films of two commercial brands, i.e. Intra X-ray and Carestream films were placed in aerobic, anaerobic, and fungal culture media immediately after removal from the packaging in sterile conditions. The samples were transferred to the respective culture media after incubation. The cultured bacteria were Gram-stained, and microscopically observed. The percentage of the contaminated intraoral radiographic films and the type of microbial contamination were reported. Data were analyzed using the Chi-square test. Results Of all, 32.6% of the Carestream films and 44.6% of Intra X-ray films were infected by aerobic microorganisms, mostly Bacillus. In the anaerobic culture, the turbidity of the medium indicated the possible presence of microorganisms. In the fungal culture, no fungal hyphae were observed microscopically. Conclusion The results of this study showed that intraoral films cannot be considered sterile. Intra X-ray radiographic films were significantly more contaminated than Care stream radiographic films.

This study investigates the frequency of isolated microorganisms and the antimicrobial resistant pattern of inner foreskin and smegma in prepubertal children.

This comparative cross-sectional study was conducted between March and November 2019, where 132 prepubertal boys, who were scheduled to receive religious circumcisions at our outpatient clinic, were examined. The patients were divided into the following groups based on the presence of smegma in their subpreputial space: Group I (with smegma, n=58) and Group II (without smegma, n=74). Sterile stuart transport swabs (Advanced Diagnostic Research, Mediko Kimya, Turkey) were taken from the smegma or the subpreputial space (glans surface and inner foreskin) using aseptic techniques and then the swab samples were immediately transported by sterile stuart transportation for microscopy, culture identification, and antibiographic resistance test-ing by conventional test methods and automated systems (VITEK II, Biomerieux, France) to the Microbiological Laboratory of our hospital.

48 bacteria isolated from 39 boys in Group I comprised 28 gram-positive species (58.3%) and 20 gram-negative species (41.7%). The most commonly isolated gram-negative bacterium was Proteus mirabilis (45%) while most positive was Staphylococcus hominis (42.9%). In Group II, 68 boys had 103 bacterial isolates in the glans comprising 81 gram-positive species (78.6%) and 22 gram-negative species (21.4%). The most com-monly isolated gram-negative bacterium was Proteus mirabilis (42.9%) while the most positive were Enterococcus faecalis (40.7%) and S. hominis (42.9%)

The subpreputial space of uncircumcised boys is colonized by various types of uropathogens resistant to multidrug drugs. Smegma does not pose additional risks to microbiological colonization in children.

To study the clinico-microbiological profile and outcomes of infectious keratitis (IK) at a tertiary eye care center in North India.

This is a retrospective, hospital-based, cross-sectional study. One thousand seven hundred and eighty-six corneal microbiological reports were identified from January 2017 to December 2018, out of which 625 patients of IK fulfilled the inclusion criteria. They underwent microbiological examination which included corneal scrapings, culture, and antibiotic sensitivity. Demographic features, signs and symptoms, risk factors such as associated trauma, previous ocular surgery, and use of corticosteroids were also recorded.

Of the 625 patients, 68.2% were male and 31.8% were female. The age group affected most was the sixth decade; 21.9% (137 cases). Trauma was the most common associated risk factor in 151 cases (24.2%) followed by previous ocular surgery in 111 (17.8%). Out of the 625 corneal scrapings, 393 (62.9%) were culture-positive. Bacterial culture accounted for 60.6% (238/393) and fungal cultures were 143 (36.4%). More than 50% of the bacterial keratitis cases and more than 60% of the fungal cases had a favorable outcome. Staphylococcus sp. and Fusarium sp. were the most common bacteria and fungus isolated, respectively. Only one-third of the cases required surgical intervention, and the remaining two-thirds were managed medically.

In the current study, cultures were positive in 63% of cases, and the majority of cases had bacterial growth. Surgical intervention was needed in one-third of the cases. Management of corneal infections is incomplete without a good microbiological workup. Ophthalmologists should be encouraged to learn and practice basic staining procedures, and this should start early in the training years.

Objective Structured Practical Examination(OSPE) is a comprehensive tool for assessment. We wanted toimprove our assessment methods and make it a more competencebasedevaluation. Thus this study was designed to compare theeffectiveness of Objective Structured Practical Examination withthat of Conventional Practical Examination. This interventional study was carried out in Departmentof Microbiology at CIMSH, Lucknow over six months fromOctober 2019 till March 2020. One hundred second year MBBSstudents were enrolled. The students were divided into twogroups of fifty for the conventional examination group (controls)and the OSPE group. On the first day, the cases appeared forOSPE while the controls for conventional examination. On thesecond day, the groups were crossed over. The students appearingfor OSPE were assessed by their scores at different stations.Feedback forms with a pre structured questionnaire were given tothe students and the examiners after OSPE on both days to recordtheir perceptions. Finally, the students’ scores were tabulated andcompared statistically. Microsoft Excel and SPSS were used fordata analysis. The data was presented as percentages, mean andstandard deviation. Student t test was used and the significancewas checked, using P value <0.05. Overall in OSPE, the students scored higher and theresult was statistically significant. The proportion of studentsin higher marks range was more for OSPE than that for theconventional method. The difference was statistically significant(P<0.001). Feedback taken from examiners as well as from thestudents in the form of a structured questionnaire to analyze theirperceptions was very encouraging. OSPE is a comprehensive assessment modality forpractical evaluation of MBBS students. OSPE proved to be aneffective tool that improved the students’ scores in microbiology.

Formation of microgaps between the fixture and abutment surfaces is still one of the major problems that may lead to mechanical and biological failure and inflammation around the implant. In this study, the effect of GapSeal on the prevention of liquid leakage and microgap in internal hex connection was investigated.

In this experimental study, sixteen internal hex implants (BioHorizons) were used in two groups. All implant-abutment assemblies were mounted in acrylic molds. GapSeal was inserted into the implants in the case group. All specimens were given a torque of 30 Ncm. Then, 1,200,000 cycles with a 100-N force and frequency of 1 Hz were applied to all samples. The samples were immersed in a methylene blue solution for microleakage evaluation. Microgap was randomly measured at six areas using scanning electron microscopy (SEM). Data were analyzed by SPSS 22 software using t-test.

The size of microgap was 3.04±0.54 µm in the control group and 0.99±0.39 µm in the case group, which was three times larger in the control group; the t-test showed that this difference was significant (P<0.000). In the control group, all samples (100%) showed leakage in the internal hex connection while in the case group, none of the samples (0%) showed leakage; Fischer's exact test showed that the difference was statistically significant (P<0.0001).

According to the results of this study, it can be concluded that GapSeal reduces microgap and microleakage in the case group compared to the control group.

This study evaluated the impact of CO2 laser treatment and acidulated phosphate fluoride (APF) on enamel demineralization and biofilm formation, using in vitro and in situ designs. Demineralized enamel slabs were distributed among 8 groups: placebo, placebo + continuous CO2 laser, placebo + repeated CO2 laser, placebo + ultrapulsed CO2 laser, 1.23% APF, APF + continuous CO2 laser, APF + repeated CO2 laser and APF + ultrapulsed CO2 laser. In the in vitro study, 15 enamel slabs from each group were subjected to a pH-cycling regimen for 14 days. In the cross over in situ design, 11 volunteers wore palatal appliances with demineralized enamel slabs for 2 periods of 14 days each. Drops of sucrose solution were dripped onto enamel slabs 8×/day. Biofilms formed on slabs were collected and the colony-forming units (CFU) of Streptococcus mutans and Lactobacillus were determined.  For both in vitro and in situ studies, there was no significant difference between treatments (P > 0.05). However, all treatments increased microhardness of demineralized enamel (P < 0.05). After a further in situ cariogenic challenge, with the exception of the placebo, all treatments maintained microhardness values (P < 0.05). Microbiological analysis showed no difference in Streptococcus mutans (P > 0.05) or Lactobacillus (P > 0.05) counts between groups.  The results suggest that APF gel combined with the CO2 laser, regardless of the pulse emission mode used, was effective in controlling enamel demineralization, but none of the tested treatments was able to prevent bacterial colonization.

Maturity-onset diabetes mellitus affecting the elderly population is marked by insulin resistance and decreased insulin production. The relationship between periodontitis and diabetes is bidirectional. Type 2 diabetic patients are more prone to chronic periodontitis (CP) and severe periodontitis affects the glycemic control in such patients. Recently, dental diode laser has become an effective tool in controlling CP. To date, very few studies have been conducted to check the efficacy of diode laser in control of periodontal destruction in type 2 diabetes mellitus (DM2) patients. Hence, the need of the study was to evaluate whether diode laser helps improvement of periodontal outcome and reduction in anaerobic bacteria in elderly diabetic patients with CP. Forty DM2 patients with CP were randomized into group A (control): scaling and root planing (SRP) only and group B (test): SRP followed by soft tissue dental diode laser (808 nm) application. Four patients (2 in each group) were lost during follow up. Clinical parameters, plaque samples and glycated hemoglobin levels were evaluated at both baseline and 90 days post-treatment. Improvement in clinical, microbiological and glycemic parameters were noted in the group that received SRP as well as SRP + LANAP (laser-assisted new attachment procedure). The reductions in clinical parameters were statistically significant after 3 months (P < 0.001). The microbial analysis of plaque samples for Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) decreased significantly after 3 months in group B than in group A. Glycated hemoglobin level (HbA1c) decreased significantly after 90 days in both the groups (P < 0.001) with more reduction in the SRP+LANAP group (6.49%) in comparison to SRP alone (16.25% vs. 9.76%). However, on the intergroup comparison, the difference in HbA1c reduction was nonsignificant. Laser as an adjunct to SRP is an effective procedure for improving clinical and microbiological parameters in maturity onset diabetes mellitus patients with CP. Also, there was a better improvement in glycemic control in the test group compared to control group after 3 months. Hence, medically compromised patients like DM2 with CP with delayed wound healing can effectively be treated by laser as an adjunct to nonsurgical periodontal therapy for better results.

Ventilator associated pneumonia is one of the most important nosocomial infections with often poor outcomes and heavy economic burdens on health care systems.

Several studies have been done for evaluating the effect of different types of stress related mucosal disease (SRMD) prophylaxis on nosocomial pneumonia, as among factors participating in its establishment, gastrointestinal tract is believed to play an important role especially in ventilator-associated pneumonia.

In this cross-sectional study, 150 patients who were admitted to intensive care unit (ICU) and developed documented culture positive VAP, were evaluated for the study inclusion criteria. The patients with clinical pulmonary infection score (CPIS) ≥ 6 were included and some others with conditions affecting comparability excluded. The patients with Acute Physiology and chronic health evaluation II (APACHEII) scores between 10 and 24, within the first 24 hours of ICU stay, were included. Finally, 100 patients who fulfilled all criteria were evaluated for the responsible organisms and type of SRMD prophylaxis they had received. The patients included were either on intravenous pantoprazole (49 patients) or intravenous ranitidine (51 patients). The goal of this study was to evaluate the organisms, which have been isolated from the sputum of ICU patients with ventilator-associated pneumonia, according to their SRMD prophylaxis regimen.

There were 59 men (59%) and 41 women (41%) ranging from 19 to 82 years old. The mean ages were not significantly different between the two groups (P = 0.586). APACHEII score was ranging between 15 and 21 with the mean of 17.57 in pantoprazole and 16.80 in ranitidine group (P = 0.006), there was a statistical but not clinical difference. With P-value of 0.001, there was significant difference in ICU stay days. The mean mortality rates were 18.4% and 1.8% for pantoprazole and ranitidine group, respectively. The difference was statistically significant (P < 0.001). Multi-drug resistant pathogens were significantly higher in the pantoprazole group (0.001). The organisms, which have been obtained from each group were different. Acinetobacter and Pseudomonas aeruginosa were highly cultivated in the pantoprazole group, while Staphylococcus aureus and Proteus were more in patients who had received ranitidine.

It can be suggested that each bacterium has a unique propensity to grow in specific gastric pH and other systemic changes made by various agents used for SRMD prophylaxis. More studies are needed to evaluate large number of patients receiving SRMD prophylaxis, with perspective of VAP incidence, the responsible organisms, hospital and ICU stay days, and mortality rate in order to prevent poor outcomes caused by specific organisms.