فهرست مطالب nakisa sohrabi haghdoost

The ocular surface is perpetually exposed to the external environment, rendering it suscep- tible 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).

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.

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 Staphylo- coccus 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.

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.

Contamination of food products, especially dairy products, with aflatoxins, is one of the main problems in the food industry. This research aimed to remove aflatoxin M1 using two probiotics, Bifidobacterium lactis and Streptococcus thermophilus, either alone or in combination, in skimmed milk containing this toxin. The study investigated the effects of storage time, microbial strain, bacterial concentration, toxin concentration, and temperature on the removal of aflatoxin M1. Two probiotic bacteria, Bifidobacterium lactis and Streptococcus thermophilus, at dilutions of 108 and 1010 CFU/ml, were inoculated alone and in combination into skimmed milk contaminated with different concentrations of aflatoxin M1 (0.1, 0.25, and 0.5 μg/ml). The samples were then incubated at 4°C and 37°C for 0.5, 1, 2, and 24 hours. The detoxification percentage of aflatoxin M1 was measured using high-performance liquid chromatography (HPLC). The results showed an increase in the removal of aflatoxin M1 with time. The removal of aflatoxin M1 by these strains varied from 12% to 87% depending on the concentration of bacteria, storage time, toxin concentration, and bacterial strain, whether alone or in combination. The results of this study suggest that using probiotics can be an effective method for reducing or eliminating the concentration of aflatoxin M1 in the dairy industry.

Mucormycosis is a severe and potentially fatal fungal infection caused by opportunistic fungi belonging to the class Zygomycetes. Coronavirus 2019 (COVID-19) is a severe worldwide disease. One of the problems faced by Covid-19 patients is concurrent infection with microbial agents such as life-threatening fungal infections. Studies show that people with diabetes who have recovered from COVID-19 are more likely to develop mucormycosis. In addition, patients with COVID-19 are at increased risk of acute heart damage, arrhythmias, thromboembolic complication, and secondary infection. However, the exact reasons and mechanisms of increasing this deadly infection need to be investigated to understand the pathogenicity and discover reasonable ways of prevention and treatment. Studies show that increasing overuse of steroids, antibiotics, and zinc as an act of self-medication during the Covid-19 epidemy may increase intestinal microbiota dysbiosis, thereby suppressing the system—immunity in the group at risk of this fungus. Ocular and cerebral mucormycosis is the most common form of the disease, with a mortality rate of over 49%, especially in patients with pulmonary or diffuse or cerebral mucormycosis. In addition, a significant proportion of survivors of the disease showed symptoms such as 46% vision loss. This article addresses potential mechanisms, host-related factors, pathogenicity, and innate and acquired immune system responses that may help understand the mystery of the sudden, severe, and fatal increase in mucormycosis infections due to Covid-19. Early detection of such conditions with the above-mentioned consequences is vital for optimal treatment and better results.

Dermatophytosis is one of the most prevalent zoonotic diseases. Increased resistance of dermatophytosis causing pathogens against antidermatophytic agents highlights the need for alternative medicine with higher efficiency and lower side effects. In the present study, the in vitro antifungal activities of different concentrations of Gracilaria corticata methanol extract against Trichophyton mentagrophytes, Microsporum canis, and Microsporum gypseum were assessed and their efficacy was evaluated in rat dermatophytosis models.

The broth microdilution and well diffusion methods were used to determine the in vitro antidermatophytic activity. The in vivo study was carried out using 40 dermatophytosis-infected adults male Wistar rats. The animals were divided into 4 groups (5% and 10% G. corticata ointment, terbinafine, and Vaseline) and treated with ointment until complete recovery. The percentage of wound closure was calculated for each group.

The results revealed that G. corticata methanol extract was effective to varying extents against the tested dermatophytes. The highest inhibitory activity of G. corticata was found against T. mentagrophytes with minimum inhibitory concentration and minimum fungicidal concentration values of 4 and 9 µg mL-1, respectively. The in vivo experiment revealed that 10% G. corticata ointment significantly accelerated skin lesions reduction and completely cured M. gypseum, T. mentagrophytes, and M. canis infections after 19, 25, and 38 days, respectively.

The methanol extract of G. corticata exhibited significant antifungal activity in vitro and in vivo, suggesting that it could be used as an alternative to antidermatophytic therapy in a dose-dependent manner.

Food contamination with aflatoxin is identified as a challenge for health and economics; therefore, global organizations have determined the minimum contamination of different foods. Aflatoxin M1 (AFM1) is a carcinogenic mycotoxin mostly found in dairy products and its removal has remained a challenge. This study aimed to evaluate the effect of anti-aflatoxin of Bifidobacterium bifidum and Saccharomyces cerevisiae in contaminated skim milk.

In order to carry out this project, skim milk was spiked with three concentrations of AFM1 and treated with two levels of bacteria and fungi concentration, alone or mixed, and incubated at 4 and 37 ˚C for different time points (30, 60, 120 min, and 24h). High-performance liquid chromatography (HPLC) was used to detect the AFM1 in milk.

The results showed that the incubation time is a key factor in the removal process of AFM1. Also, the removal of AFM1 was dependent on other factors such as the concentration of microorganisms, incubation temperature, toxin concentration and type of treatment (alone or combination). The ability of these strains to remove AFM1 after 24 hours was shown to be 20-90%. The removal of AFM1 by Saccharomyces cerevisiae (66.8%) as compared to Bifidobacterium bifidum (51.3%), and the combination of probiotics increased their ability to remove the toxins (90%).

The results of this study showed that probiotics alone or in combination with each other play an essential role in removing AFM1 from milk.

Candida albicans is an aggressive pathogen and the main etiologic agent in the genus Candida, accounting for 42.5% of infections. The existence of hyphal form along with adherence is critical to colonize mucosal surfaces and cause infection. Adherence of C. albicans to host tissue is crucial to colonize cells; therefore, these microorganisms use proteins named adhesins. HWP1, a protein associated with adhesins, serves as a substrate for mammalian transglutaminases and plays an important role in adherence to epithelial cells. Due to the emergence of antifungal drug resistance, the present study aimed at determining the effect of propolis ethanolic extract (a natural product with antifungal properties) on the HWP1 gene expression in clinically isolated C. albicans strains. The HWP1 gene expression was analyzed using real-time PCR, and HWP1 expression was normalized against the ACT1 housekeeping gene. After the treatment of clinical samples with propolis ethanolic extract, the relative level of HWP1 gene expression was 0.88, 0.53, 0.21, and 0.66% for the standard strain, and those isolated from the oral cavity, nail, and vaginal cavity, respectively. The decrease in HWP1 expression might affect C. albicans virulence, and propolis ethanolic extract might be used as an alternative remedy for antifungal drugs