Iranian Journal of Microbiology最新文献

Background and objectives: Candida parapsilosis is the second most common species causing infectious diseases and can lead to biofilm resistance. This study aims to adjust and synthesize a liposomal compound of Nigella sativa and evaluate its antifungal properties against C. parapsilosis isolates.

Materials and methods: The liposomal formulation of N. sativa was optimized through the utilization of transmission electron microscopy (TEM), particle size analysis, zeta potential measurement, and UV-visible spectrophotometry. Furthermore, an MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay was conducted on peripheral blood mononuclear cells (PBMCs). The antifungal efficacy was evaluated in accordance with the M27-A3 guideline.

Results: The minimum inhibitory concentrations (MICs) of N. sativa oil and the liposomal formulation on C. parapsilosis isolates ranged from 128 to 8 µg/mL and from 250 to 31.25 µg/mL, respectively. The MIC₅₀ and MIC₉₀ values of N. sativa oil and the liposomal formulation were 125, 187, and 32, 96 µg/mL, respectively. The viability percentage of cells treated with the liposomal formulation and free N. sativa oil was 91% and 85%, respectively.

Conclusion: The cytotoxicity of free N. sativa was significantly reduced when using nanoliposomes. The liposomal form of N. sativa showed greater antifungal properties compared to the free N. sativa extract against C. parapsilosis isolates.

Background and objectives: Helicobacters are gastric and enterohepatic and live in the gut. The role of enterohepatic Helicobacters as intestinal pathogens is uncertain, while stomach Helicobacters are well-known. The prevalence of Helicobacter species in cat feces helps us understand their impact on cat health and human disease transmission. This study used PCR to identify Helicobacter spp. in feces samples from healthy and diarrhoeic cats, independent of the reason. The study also compared intestinal and stomach Helicobacter species.

Materials and methods: PCR analysis was performed on fecal samples from 40 cats, with 20 cats having diarrhea and 20 cats showing no symptoms. The PCR analysis aimed to detect Helicobacter's presence using a method that identifies the bacteria through the 16S rRNA gene.

Results: The diarrhoeic group had a greater prevalence of infection (17:9 ratio), with an overall 65% infection rate detected. Cats that were older than 2 years showed a higher incidence of disease. H. canis had the highest occurrence rate (69.2%), followed by H. bilis, H. bizzozeronii, and H. salomonis. Significantly, H. pylori, H. felis, and H. heilmannii were not reported.

Conclusion: H. canis was the predominant species found in both healthy and diarrheic cats, indicating the need for more investigation. The detection of the gastric species H. salomonis and H. bizzozeronii further complicates the classification. This highlights the complex nature of Helicobacter infections in cats, emphasizing the need for further investigation to guide the development of preventative measures and treatment techniques for both veterinary and public health purposes.

Background and objectives: Staphylococcal infections are one of the major infectious diseases affecting globally in spite of advances in development of antimicrobial agents. Knowledge and awareness about the local pattern and prevalence of MRSA infections plays a key role in treatment. The aim of this study was to identify MRSA strains by phenotypic and genotypic methods and to analyze the antibiotic susceptibility pattern of MRSA strains from patients attending a tertiary care hospital.

Materials and methods: This study was conducted over a period of 1 year, where 296 isolates of Staphylococcus aureus were isolated from various clinical specimens. The isolated strains were examined for antibiotic susceptibility by the modified Kirby Bauer disc diffusion method. Methicillin resistance was detected by cefoxitin disk diffusion test.

Results: A total of 104 isolates were found to be MRSA and 192 were found to be MSSA. Among the 104 MRSA isolates, 10 strains that were multidrug resistant were subjected to 16S rRNA gene sequencing analysis. All the 10 strains had a 99% match with S. aureus strains that were responsible for causing some serious biofilm mediated clinical manifestations like cystic fibrosis and device mediated infections. The biofilms were quantified using crystal violet staining and their ability to produce biofilms was analyzed using scanning electron microscopy and matched with the Genbank.

Conclusion: Hence these phylogenetic analysis aid in treating the patients and combating resistance to antibiotics.

Background and objectives: Microbial biofilm is characterized by the irreversible attachment of planktonic cells to a surface and is usually associated with high antimicrobial resistance with worsening the wound healing. The objective of the study was to determine the prevalence of Staphylococcus aureus in diabetic foot ulcers (DFUs) of diabetic patients and to investigate antibiotic susceptibility patterns of these isolates. In addition to screen biofilm forming ability of isolated S. aureus.

Materials and methods: A total of 112 non-healing wound swabs of diabetic foot patients were collected and cultured on different culture media to identify and characterize 98 isolates. The S. aureus isolates were examined for their antibiotic susceptibility to different antimicrobial agents. Furthermore, S. aureus isolates were evaluated for their biofilm production capability using the Tissue Culture Plate Method (TPC). The level of icaA gene expression was determined by RT-PCR.

Results: The results of this study showed that these non-healing wounds yield positive cultures, with an average of 1.67 organisms per sample. The isolates showed highest resistance against oxacillin (95.2%) and lowest resistance against linezolid (3.7%). All isolates were biofilm producers and a significant association with the icaA gene expression level was recorded.

Conclusion: This study showed that S. aureus isolates have a great ability to produce biofilms that are associated with the chronicity of wounds in diabetic patients. Routine screening for biofilm formers in chronic wounds and their antibiotic susceptibility testing will help in early treatment and prevent any other complications.

Background and objectives: The consumption of contaminated poultry meat is considered as a significant route of campylobacteriosis transmission. Lactic acid is a disinfectant agent with bactericidal effects on Campylobacter spp. The purpose of this study was to assess the low concentrations of lactic acid effect and different temperatures on the transcriptomic responses of Campylobacter jejuni (C. jejuni) adhesion and virulence-associated genes including peb4, ciaB, cdtA, cdtB, and cdtC.

Materials and methods: The samples were incubated at 10°C and 22°C for 48 h upon exposure to 30% and 60% lactic acid. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of lactic acid was also determined. Then, gene expression was assessed using real-time polymerase chain reaction (RT-PCR).

Results: Lactic acid had lower MIC and MBC levels at lower temperature. The utilization of both levels of lactic acid significantly reduced the expression of peb4, ciaB, cdtB, and cdtC genes over 48 h of incubation at 22°C. However, no significant difference was found in the expression of the cdtA gene between 10 and 22°C at 30% lactic acid.

Conclusion: These results highlight the potential of low-concentration lactic acid in the downregulation of adhesion and virulence-associated genes as well as reduction of C. jejuni pathogenicity.

Background and objectives: Fungal burn wound infections (FBWIs) are one of the most disastrous complications in burn patients. The present study investigated the incidence and the species distribution of fungal agents isolated from burn lesions and reviewed the feautures, underlying conditions, and outcomes of patients.

Materials and methods: The wounds were swabbed and cultured on Sabouraud Dextrose Agar with chloramphenicol medium. Fungal identification was performed using internal transcribed spacer (ITS) and beta-tubulin sequencing.

Results: A total of 380 swab specimens were obtained. Of these, 101 patients (26.75 %) were positive in culture. Among the 101 positive cases, most isolates were from males (n= 68, 67.33%) and most of them were over 30 years old. Flame (n=38, 37.63%) was the predominant cause of burns, and previous history of ICU admission (n=35, 34.66%), presence of central venous catheter (n=25, 24.75%), and diabetes mellitus (n=17, 16.83%) were the main underlying conditions. Candida parapsilosis complex (n=36, 35.64%), and Pichia kudriavzevii (C. krusei) (n=8, 7.92%) represent the most commonly isolated species Also, 2 out of 101 patients (2%) died.

Conclusion: In the present study, non-albicans Candida species were much higher frequent than C. albicans with most cases associated with Candida parapsilosis complex.

Background and objectives: Cervical cancer global burden is highly skewed towards poor countries primarily due to lack of awareness, poor screening, and low uptake of prophylactic vaccines. The purpose of our study is to educate and raise awareness among young girls and women about the importance of cervical screening and HPV vaccination.

Materials and methods: The present study, conducted from January 2023 to December 2023, focused on students, teachers, housewives, and healthcare professionals in the Jammu region to assess their awareness of cervical cancer and the HPV vaccine. HPV DNA testing was carried out using the Truenat Real-Time PCR method at Swastik Diagnostic Laboratory, Jammu.

Results: Knowledge of cervical cancer, awareness of the HPV virus, and the vaccination status of women were assessed in survey. In the HPV screening test, out of 2,400 women, 106 tested positive for HPV. Among these 106 women, 19% had a high viral load (Ct < 20), 11% had a low viral load (25 ≤ Ct < 30), indicating a low relative concentration of HPV viruses, 40% had a medium viral load (20 ≤ Ct < 25), and 30% had very low viral loads (Ct ≥ 30).

Conclusion: These findings highlight the importance of routine cervical screenings, such as Pap smears and HPV tests, for the early detection of cervical cancer. There is an urgent need to implement cervical cancer screening and vaccination programs in the Jammu region.

Background and objectives: The ocular surface is perpetually exposed to the external environment, rendering it susceptible to microbial contamination. The ocular surface microbiota consists of non-pathogenic microorganisms that inhabit the conjunctiva and cornea. This study's objective was to extensively review the prevalence of bacterial and fungal organisms in the conjunctiva of healthy and diseased cats. (Herpes- and Calici-infected groups).

Materials and methods: The current study was performed on 240 cats that had visited veterinary health centers (Tehran, Iran) for examination. Sterile swabs from each cat's eyes were investigated for microbiological assessment. After sample collection, viral pathogens (Herpes and Calici viruses) were isolated and identified using the PCR method. The ages of the investigated group were 3.76, 3.93, and 4.15 months.

Results: The highest frequency of bacteria in the normal, Herpes-infected/Calici-infected, and Herpes/Calici-infected groups were associated with Staphylococcus intermedius and Streptococcus agalactiae, Staphylococcus epidermidis, and Staphylococcus intermedius, respectively. In addition, it was found that the high prevalence of fungal microorganisms in the isolated samples was related to yeasts, Aspergillus (Aspergillus fumigatus, Aspergillus niger), and Penicillium species.

Conclusion: Bacterial prevalence was significantly higher in all groups than the prevalence of fungi in the eyes of cats. The statistical comparison between the study groups regarding microbial and fungal frequency showed that significant differences were found between them, such that the frequency was higher in all disease groups, against the control group. In addition, a significant relation was observed between the Herpes-infected and Calici-infected groups regarding microbial and fungal prevalence.

Background and objectives: Today, medicinal plants and their derivatives are considered to reduce the prevalence of antibiotic resistance. The aim of this study was to investigate the effect of Mentha longifolia essential oil on oqxA efflux pump gene expression and biofilm formation in ciprofloxacin-resistant Klebsiella pneumoniae strains.

Materials and methods: A total of 50 clinical strains of K. pneumoniae resistant to ciprofloxacin were studied. The minimum inhibitory concentration (MIC) of M. longifolia essential oil and its synergistic effect with ciprofloxacin were determined using the microbroth dilution method and the fractional inhibitory concentration (FIC) method. Minimum biofilm inhibition concentration (MBIC) of M. longifolia essential oil was detected. The effect of essential oils on the expression level of the oqxA gene was detected by Real-time PCR.

Results: M. longifolia essential oil showed inhibitory activity against ciprofloxacin-resistant strains of K. pneumoniae. When M. longifolia essential oil was combined with ciprofloxacin, the MIC was reduced 2-4 times. In 28% of the strains, M. longifolia with ciprofloxacin showed a synergistic effect. M. longifolia essential oil reduces the strength of biofilm formation and alters the biofilm phenotype. A significant decrease in oqxA gene expression was observed in all isolates after treatment with M. longifolia essential oil.

Conclusion: Based on the results of this study, it was observed that supplementing M. longifolia essential oil can help reduce ciprofloxacin resistance and inhibit biofilm formation in fluoroquinolone-resistant K. pneumoniae strains.

Background and objectives: This study evaluated the efficacy of the TrueLab™ Real Time mini-PCR system in providing rapid and accurate diagnostic results for tuberculosis (TB) detection in India. The goal is to improve case detection and accelerate treatment in settings with limited resources.

Materials and methods: This prospective study was conducted by the Department of Microbiology on 120 patients, age ranging from >=15 years with at least two clinical symptoms of pulmonary TB. Molbio and Universal Cartridge Based Sample Prep were the 2 methods used for processing sputum samples. The diagnosis was based on the MTB Real Time PCR test, which has a detection limit of 100 CFU/mL. Patients under 15 years, samples lacking clinical background, saliva specimens or extra-pulmonary TB cases were excluded from the study.

Results: A total of 44.17% samples were positive for TB with maximum positivity in the age group 31-45 years. Positivity rate was found to be higher in females. In 4.17% of cases there was rifampicin resistance, which was significantly high in previously treated cases. Comparison of Truenat with Ziehl-Neelsen and fluorescent method revealed that it was more sensitive and less time consuming.

Conclusion: Truenat MTB/RIF is a sensitive detection system for TB with rapid results, which serves as an important tool in the early management of tuberculosis patients and drug-resistant-TB cases.