bacteria

 Staphylococcus aureus is a highly significant pathogen responsible for infections and fatalities among patients in the intensive care unit (ICU) of hospitals. This study aimed to determine the frequency of antibiotic resistance in S. aureus strains isolated from urine, blood, and wound samples of hospitalized patients in the ICU of hospitals in Ahvaz, Iran.

 A total of 113 samples were collected during the sampling process. These samples were cultured on blood agar and eosin methylene blue (EMB) agar, followed by an incubation period at 37° C for 24 hours. The identification of S. aureus was based on the appearance of grayish-white colonies and a series of tests, including Gram stain, catalase, Mannitol salt agar, DNase, and tube coagulase tests. The isolates were analyzed using antibiograms to test for susceptibility to oxacillin, cefoxitin, linezolid, ciprofloxacin, clindamycin, trimethoprim, sulfamethoxazole, rifampicin, penicillin, and erythromycin.

 The prevalence of S. aureus was highest in blood samples (49.55%) and lowest in urine samples (32.12%). All strains of tested S. aureus were sensitive to the antibiotic linezolid, while 90% of methicillin resistance S. Aureus (MRSA) found in blood samples were sensitive to rifampicin. The highest prevalence of S. aureus was found in Golestan hospital, accounting for 21.23%. The antibiotics with the highest resistance against MRSA in blood culture samples were penicillin (100%), clindamycin (88.9%), ciprofloxacin (81.81%), erythromycin (80.7%), and trimethoprim-sulfamethoxazole (73.52%). The polymerase chain reaction (PCR) results for gene prevalence revealed that 110 isolates contained this gene, while 3 isolates lacked it. Using the national multiplex PCR method for SCC typing, 47 isolates (7.42%) expressed SCC III, and 33 isolates (30%) expressed SCC II.

 The study findings revealed significant resistance to certain antibiotics in the hospital strains of S. aureus. Likely, the misuse of antibiotics, taken without a physician’s prescription contributes to this complication.

The discovery of novel therapies and the provenance of antimicrobial medication are critically important, as antimicrobial resistance is becoming more common because of the presence and continuous evolution of antimicrobial-resistant organisms. Studies regarding synergy in medicinal plant extracts with antimicrobials have emerged as a novel and important research field. The synergy itself can serve as a beneficial tactic to strengthen and replenish antimicrobial medications that are currently less effective in clinical settings when treating microbial infections that are multi-resistant. The current work is a web-based search performed using PubMed, which covered studies that were published over more than a 25-year period, specifically between 1997 and July 2024, and assessed the potential for synergy between plant extracts and conventionally prescribed antimicrobial medications. The findings of the current review held great promise for the development of novel plant-based remedies combined with clinical-in-use antimicrobial medications to be exceptionally successful in treating severe infections that are resistant to antimicrobial treatments alone.

To determine the sperm DNA fragmentation in the semen of suspected sub-fertile men of Nepal and find its association with bacteriospermia demographic and lifestyle factors.

A cross-sectional study was conducted with the subjects, males among sub-fertile couples visiting a fertility center in Kathmandu Valley, Nepal for consultation. Information on demography and exposure factors was obtained with a structured questionnaire, and bacteriospermia and sperm DNA fragmentation was determined from the semen samples collected from the study subjects. The data obtained were used to assess sperm DNA fragmentation and its association with various risk factors in sub-fertile men of Nepal.

Out of 186 samples analyzed, 41.4% had low DNA fragmentation (<15%), 38.7% had moderate DNA fragmentation (≥15% and <30%), and 19.9% had high DNA fragmentation (≥30%). Among the risk factors analyzed, sperm DNA fragmentation was found to be significantly associated with the age of the patients (p<0.05). Other factors analyzed body mass index, smoking, alcohol consumption, physical activity, and bacteriospermia were not found to be associated with sperm DNA fragmentation in our study.

Sperm DNA integrity may be distorted with the increasing age of men, leading to decreasing fertility potential.

Cancers are extremely dynamic diseases that can actively cause refractorines to be gained from applied therapies, which is why they are at the forefront of deaths worldwide. In this literature review,  we covered the most recent and important discoveries regarding the influence of human microbiota, including tumor bacteriome, on the development and treatment of cancer. Advances in research on microbial communities have enabled us to discover the role of the human microbiome in the development and course of this disease, helping us understand neoplasms better and design new potential therapies. As we show through our findings, by immunomodulation and the secretion of certain chemical substances, the correct bacteriome of the intestinal tract, respiratory system, or skin can protect humans against cancer development and help during the treatment process. Bacteria also reside inside tumors, forming part of the tumor microenvironment (TME), where they interact with immunological and cancer cells in many complex ways. Some bacteria, such as Pseudomonas aeruginosa or Akkermansia muciniphila, can stimulate anticancer cell-mediated immune responses or even directly lead to cancer cell death. We also present the clinical possibilities of using some live, usually modified bacteria to develop bacteriotherapies. Modifying the gut microbiome to stimulate standard treatment is also important. Research on the microbiome and cancer remains a challenging topic in microbiology, having a great potential for advancements in cancer therapy in the future, and is continuously becoming a more and more popular field of research, as shown by our statistical analysis of PubMed data.

Urinary tract infections (UTIs) are considered as a major public health issue, often causing complications. Although the traditional cultivation approach is reliable in diagnosis, it is time-consuming, leading to delay in treatment and contributing to antibiotic resistance due to suboptimal empirical treatments. This study aimed to evaluate the performance of a direct, rapid identification technique using MALDI-TOF MS for pathogen identification and antibiotic susceptibility testing in UTIs, aiming to reduce diagnostic time compared to standard culture methods.

In the span of a year, 458 monomicrobial urine samples were analysed using both the standard bacterial culture method and the direct MALDI-TOF MS-based method. Antibiotic susceptibility was directly tested on 20 samples using the disk diffusion method.

The direct identification technique accurately identified 92.14% of microorganisms at the genus level and 60.92% at the species level within an hour, significantly faster than the 24 to 48 hours required by traditional culture methods. The direct antibiotic susceptibility test results were consistent with the standard post-culture method ranging from 60.00% to 100%.

Direct identification using MALDI-TOF MS can improve UTI management by enabling faster pathogen identification and targeted treatments, potentially reducing antibiotic resistance. Further studies are needed in terms of enhancing its clinical utility and reliability.

The gut ecosystem, comprising the gut microbiota and its interactions, plays a crucial role in human health and disease. This complex ecosystem involves a diverse array of microorganisms such as viruses, fungi, and bacteria, collectively known as the gut microbiota. These microorganisms contribute to various functions, including nutrient metabolism and immune modulation, thereby impacting human health. Dysbiosis, or an imbalance in the gut microbiota, has been associated with the pathogenesis of several diseases, ranging from intestinal disorders such as inflammatory bowel disease to extra?intestinal conditions such as metabolic and neurological disorders. The implications of dysbiosis in the gut ecosystem are far?reaching, affecting not only gastrointestinal health but also contributing to the development and progression of conditions such as autoimmune gastritis and gastric cancer. Furthermore, the burden of antimicrobial use and subsequent side effects, including antibiotic resistance, poses additional challenges in managing gastrointestinal diseases. In light of these complexities, investigating the role of bacteriophages as regulators of the gut ecosystem and their potential clinical applications presents a promising opportunity to tackle antibiotic resistance and fight infectious diseases.

Bacterial toxins are virulence factors that manipulate the functions of host cells and take over the control of main processes of living organisms. Importantly, they are non-curable, non-contagious, and non-infectious by chemotherapeutic agents and/or antibiotics. The multifactorial nature of the toxicity of bacterial toxins has made their investigation more complicated.

In this review, we investigated some biological activities, structure, and action mechanism of several bacterial toxins using data from studies published in major international databases.

Bacterial protein toxins are very diverse based on size, structure and mode of action. Based on the structure and the type of cell surface receptors, the mentioned toxins have activity on the cell surface (signal transmission, pore formation) or have intracellular activity. Many bacterial protein toxins have the ability to enter the cell by the endocytosis mechanism, and according to their intracellular targets, they can induce different intracellular effects, which in many cases lead to the death of the target cell. A large and interesting group of bacterial toxins are enterotoxins. The majority of toxigenic bacteria are environmental, and the digestive system is one of the most common ways of entering or encountering environmental bacteria or their toxic products through eating food. Many enteropathogenic bacteria produce enterotoxins in food, in the intestinal lumen or on the surface of the intestinal mucosa. Also, some entero-invasive bacteria penetrate the cells by inoculating some toxins into the intestinal cells. The challenge of studying bacterial toxins and enterotoxins lies in their complex nature and the need for comprehensive characterization, but the future holds promise with advancements in technology and interdisciplinary approaches to further our understanding and develop effective strategies for prevention and treatment.

Exudative diarrhea is a significant global public health issue, particularly affecting children under the age of 5. Identifying the cause of diarrhea is crucial for epidemiological surveillance and, in some cases, for ensuring appropriate treatment for patients.

The aim of this study was to investigate the frequency of bacteria responsible for exudative diarrhea in samples from children under five years old in a tertiary hospital in Iran.

In this multicenter cross-sectional descriptive study, 104 children with exudative diarrhea who were referred to Mofid Children's Hospital in Tehran, as well as hospitals in Hamedan, Ardebil, and Bandar Abbas, from December 2020 to March 2022 were enrolled. DNA extraction was performed using a commercial kit, and the identification of various causative bacteria was conducted through conventional and real-time PCR. Descriptive and inferential statistics were analyzed using SPSS version 22 software.

Most of the children with exudative diarrhea were under 12 months old (31%) or between 12 and 24 months old (22%). Boys made up 66% of the participants. Additionally, 70% of the children had a fever, and 58% experienced vomiting. Furthermore, 56% of the patients were dehydrated. The most prevalent bacterial causes of exudative diarrhea were Shigella spp., followed by Salmonella spp., Campylobacter spp., Clostridium difficile, E. coli-Stx1 , and E. coli-Stx2 .

The findings indicated that * Shigella * spp. was the leading cause of diarrhea in children under five years old. The most common signs and symptoms associated with exudative diarrhea were fever and vomiting, which physicians should consider in their diagnostic and treatment processes.

The aim of this study was to determine the bacterial contamination of surfaces and water of dental units of Qazvin University of Medical Sciences.

This cross‑sectional descriptive study was conducted on the surgery and periodontal units at the Faculty of Dentistry, Qazvin University of Medical Sciences in 2017. Totally, 108 samples were collected from different parts of the dental units. Total Staphylococcus aureus, Pseudomonas aeruginosa, Legionella pneumophila, and Escherichia coli were counted before and after disinfection by deconex.

The results of this study showed that before and after disinfection, S. aureus, P. aeruginosa, and Coliforms were the most frequent bacteria in periodontal (100%, 100%, and 100%, respectively) and surgery wards (100%, 100%, and ˃83%, respectively). There was no significant relationship between pre and postdisinfection in terms of S. aureus and P. aeruginosa for other parts of the surgery and periodontics units (p ˃0.05). Furthermore, the statistical results indicated that all parts of the surgery and periodontics surfaces were statically significant pre and postdisinfection in term of Coliforms (p ˂ 0.05).

It can be concluded that the rate of microbial pollution in water lines and surfaces of the dental units is high. Furthermore, since a significant number of bacteria were identified after disinfection, it indicates the improper use of disinfectants.

Waterlines in dental units can harbor various types of bacteria and microorganisms, including heterotrophic bacteria, which can pose a health risk to patients and dental personnel. This study aimed to investigate the extent of heterotrophic bacterial contamination in the waterlines of dental units and evaluate its potential as a health risk factor for occupational and patient exposure. This cross-sectional study selected four active departments at the Faculty of Dentistry, Golestan University of Medical Sciences (Gorgan, Iran). Bacterial contamination in the waterlines, dental handpieces, and other water-related components of dental units was investigated and analyzed in terms of Colony-Forming Units per milliliter (CFU/ml). The data were analyzed using the Kruskal-Wallis and Wilcoxon signedrank tests using SPSS version 23. The mean and standard deviation of bacterial contamination across all studied departments were significantly higher than the recommended limit of 500 CFU/ml (ranging from 10,250.00±8,924.28 CFU/ml for the inlet to the water tank in the pediatric department to 275,625.00±41,520.86 CFU/ml for the air-water syringe before flushing in the surgery department). No significant differences were observed between departments (P>0.05). Furthermore, there were no significant differences in bacterial contamination between different days and hours of sampling (P>0.05), although bacterial levels were higher on Saturdays and mornings. Flushing the waterlines for 30 seconds reduced bacterial contamination (P<0.05). Stagnation of water in dental unit waterlines, particularly over weekends or after working hours, using reserve water during dental procedures, and insufficient flushing of dental handpieces resulted in consistently high bacterial contamination levels. Therefore, using fresh water and performing proper flushing in dental handpieces is strongly recommended to mitigate the risks associated with bacterial contamination.

Community-acquired pneumonia (CAP) in childhood is an acute lung infection in a child caused by a pathogen originating outside the hospital, i.e., in the community. This disease is a significant cause of illness in developed countries and a major cause of death in developing countries.

This study aims to assess the factors predicting the incidence of pulmonary complications in children with community-acquired pneumonia.

This study involved all children hospitalized in Zahra Mardani Azari Children's Hospital in Tabriz due to CAP between October 2022 and October 2023. Patients were compared in terms of demographic information, prescription records, medicines prescribed during hospitalization, clinical signs and symptoms, laboratory findings at admission and during hospital treatment; imaging results, and the clinical course of the disease. The study data was analyzed using SPSS version 23 software; and we used logistic regression analysis for identifying the related risk factors.

We included 361 patients, of which 104 (28.8%) were in the case group, and 257 (71.2%) were in the control group. The frequent complication was parapneumonic effusion (81.7%) following necrotizing pneumonia (27.9%), empyema (20.2%), and lung abscess (6.7%). Risk factors for pulmonary complications in children with CAP were weight (OR = 1.129), height (OR = 1.112), Body Mass Index (BMI) (OR = 1.112), administration of oral and intravenous acetaminophen during hospitalization (OR = 1.112, 1.209), Tachypnea (OR = 5.178), duration of Fever (OR = 1.290), ESR (OR = 1.312) and HRAD (OR = 3.473).

We found that high weight and BMI, receiving acetaminophen during hospitalization, Tachypnea, and Fever duration until hospitalization, as well as high WBC and ESR, were predictive factors of pulmonary complications in children with CAP.

Nosocomial sepsis is a leading cause of morbidity and mortality worldwide. Understanding the antibiotic susceptibility patterns of pathogens specific to each geographic region is essential for effective patient management.

This cross-sectional study aimed to investigate the microorganisms causing nosocomial sepsis and their antibiotic sensitivity in patients admitted to three referral hospitals in Isfahan, Iran. Clinical information and blood culture results were obtained from hospital records. Results from patients without signs of sepsis, as well as contaminants and community-acquired isolates, were excluded. Stratification was conducted based on sex and age (< 20 and > 20 years) categories.

In this study, 267 patients with hospital-acquired sepsis were identified, with gram-negative bacteria accounting for 77.2% of infections. The most common pathogens included Klebsiella spp. (35.2%), Acinetobacter spp. (21.7%), Enterococcus spp. (13.5%), Escherichia coli (8.6%), Pseudomonas aeruginosa (8.6%), and Staphylococcus aureus (8.2%). The highest resistance among gram-negative bacteria was observed with cefepime (80.3%), ceftazidime (76.5%), cefotaxime/ceftriaxone (70.0%), trimethoprim-sulfamethoxazole (68.6%), ciprofloxacin (68.2%), meropenem (60.0%), and amikacin (50.3%). All gram-negative isolates were sensitive to colistin. Among gram-positive bacteria, the highest resistance was to ciprofloxacin (77.3%), ampicillin (75.7%), clindamycin (74.4%), vancomycin (64.9%), and gentamicin (30.0%). All gram-positive isolates in this study were sensitive to linezolid.

The study indicates a high level of resistance among bacterial agents causing nosocomial sepsis in the studied area. Consequently, treatment may necessitate the use of last-line antibiotics, such as linezolid and colistin.

Endometriosis is a common disorder that affects 20 - 50% of infertile women. The disease correlates with the presence of lactobacilli and changes in the number of Gram-negative and Gram-positive bacteria.

This article aims to investigate the interaction between endometriosis and certain bacteria.

One hundred women between 18 and 40 years of age referred to the IVF department of Arash Women's Hospital in Tehran were studied. Fifty of them were diagnosed with endometriosis, while the rest were referred for investigation or freezing of their gametes or embryos. Specimens were collected from endometrial tissue and the cervix using swabs. These specimens were used for cultures and real-time PCR to quantify Lactobacillus .

Seventeen different Gram-positive and Gram-negative bacteria, as well as three yeasts, were isolated from women with and without endometriosis. The highest prevalence was related to Enterococcus faecalis , followed by Escherichia coli , Klebsiella pneumonia e, Staphylococcus aureus , E. faecium , Proteus mirabilis , Edwardsiella tarda , and Citrobacter spp. In cases with endometriosis, the relationship between the increase of Enterococcus spp., members of the Enterobacteriaceae family, and the decrease of lactobacilli was significant (P < 0.05). Staphylococcus aureus was isolated from the cervix of three women with endometriosis. The bacterial profiles of the cervix and endometrium were very similar.

Considering the decrease of lactobacilli and the increase of other bacteria in people with endometriosis, it is recommended to use Lactobacillus and other probiotics for the prevention and even treatment of this disease.

The lack of understanding of how pollutant removal occurs in biofilter reactors and bacterial community dynamics makes this worthy of study. This review explores biofiltration processes, commonly used biofilter types, bacterial community dynamics, and pollutant removal mechanisms in biofilters.

This review used data from previous studies published on Scopus, EBSCO, and ProQuest, categorized into parameters such as the biofiltration process, types of biofilters, bacterial community dynamics, and pollutant removal mechanisms. The data were narrated, analyzed in a table, and presented in a review.

In the biofilter reactor, microorganisms cover the medium, allowing pollutants to flow through gaps and contact the biofilm layer. As the biofilm thickens, adhesion weakens, leading to new colonies. Submerged-bed biofilters, trickling filters, and packed column aeration and gasification systems effectively remove nutrients from aquatic environments. Biofilter bacterial communities are categorized by filter layer depth, with fast-growing, less specialized communities in the upper layer and more specialized communities in the bottom layer. Pollutant biodegradation depends on various factors such as nutrient availability, oxygen concentration, pH, bioavailability of contaminants, and physical and chemical characteristics of the biomass.

A biofilter reactor uses microorganisms to cover a medium, allowing pollutants to flow through gaps and contact a biofilm layer that degrades organic compounds. Submerged-bed biofilters, trickling filters, and packed column aeration systems can effectively remove pollutants. Biofilter bacterial communities are categorized by filter layer depth, with fast-growing, less specialized communities in the upper layer, and more specialized communities in the bottom layer.

Every year around the world, hospital infections and resistance to antibiotics lead to many complications in hospitalized patients. This study aimed to determine and compare the antibacterial effect of hydroalcoholic extract of Rosa canina plant (Rosa canina L) on Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus bacteria isolated from surgical wounds in Yasuj hospitals.

In this cross-sectional study, the effect of Rosa canina L hydroalcoholic extract on 20 samples of Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus was investigated. The Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and zone of inhibition (ZOI) of each clinical sample were investigated and compared with the standard sample. The results were statistically analyzed by SPSS 16 software.

Rosa canina L hydroalcoholic extract had no antibacterial effect on Pseudomonas aeruginosa. The lowest inhibitory concentration was related to Staphylococcus aureus 125 µg/ml, Escherichia coli 325 µg/ml and Klebsiella pneumoniae 350 µg/ml, respectively. The difference in minimum MIC, MBC and ZOI between clinical and standard samples was not statistically significant. The ZOI diameter of Klebsiella pneumoniae and Escherichia coli clinical samples were equal (9.8 mm).

The hydroalcoholic extract of Rosa canina L has a better antimicrobial effect on Staphylococcus aureus than the other 3 investigated bacteria and has no effect on Pseudomonas aeruginosa. There is no difference between the effect of the examined extract on clinical and standard samples, and the effect of this extract on different bacteria is different.

Treatment of municipal wastewater is essential to remove bacteria. This study is designed to evaluate the efficacy of a wastewater treatment plant (WWTP) for the removal of bacteria and using for irrigation or discharge in the Caspian Sea according to the World Health Organization (WHO) regulations.

A total of 105 samples were collected from 7 stations, including the inlet and the outlet of the WWTP in Bandargaz City (Iran), the intersection point of wastewater effluent with Caspian Sea (Gorgan Bay), and a radius of 200 meters in three directions east, west, and north of the intersection point of wastewater in Gorgan Bay. The multiple-tube fermentation technique was used to enumerate bacteria, and results were expressed as the Most Probable Number (MPN) per 100 ml.

Bacteriological analysis exhibited that the concentration of total coliform, fecal coliform, fecal streptococci, and Clostridium perfringens were 1.38 ×1010, 5.57 × 107, 5.53 × 109, 1.26 × 109 in inlet, and 1.38 × 1010 , 5.57 × 107, 5.53 × 109 , 1.26 × 109 in outlet of WWTP, respectively.

The aeration lagoon has a low performance in bacteria population removal, which may be due to the climate condition of this region (few sunny days and many cloudy and rainy days). This effluent was not generally acceptable for discharge in the environment and reuse. Therefore, it is essential to modify the disinfection process to keep the concentration of bacteria under control. Additionally, continuous monitoring is necessary to control the quality of wastewater  before discharge into the environment or reuse.