Host and Pathogen-Directed Therapies against Microbial Infections Using Exosome- and Antimicrobial Peptide-derived Stem Cells with a Special look at Pulmonary Infections and Sepsis.

Microbial diseases are a great threat to global health and cause considerable mortality and extensive economic losses each year. The medications for treating this group of diseases (antibiotics, antiviral, antifungal drugs, etc.) directly attack the pathogenic agents by recognizing the target molecules. However, it is necessary to note that excessive use of any of these drugs can lead to an increase in microbial resistance and infectious diseases. New therapeutic methods have been studied recently using emerging drugs such as mesenchymal stem cell-derived exosomes (MSC-Exos) and antimicrobial peptides (AMPs), which act based on two completely different strategies against pathogens including Host-Directed Therapy (HDT) and Pathogen-Directed Therapy (PDT), respectively. In the PDT approach, AMPs interact directly with pathogens to interrupt their intrusion, survival, and proliferation. These drugs interact directly with the cell membrane or intracellular components of pathogens and cause the death of pathogens or inhibit their replication. The mechanism of action of MSC-Exos in HDT is based on immunomodulation and regulation, promotion of tissue regeneration, and reduced host toxicity. This review studies the potential of mesenchymal stem cell-derived exosomes/ATPs therapeutic properties against microbial infectious diseases especially pulmonary infections and sepsis.

Interaction Between SARS-CoV-2 and Pathogenic Bacteria.

The novel human coronavirus, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), which results in the coronavirus disease 2019 (COVID-19), has caused a serious threat to global public health. Therefore, many studies are performed on the causes and prevalence of this disease and the possible co-occurrence of the infection with other viral and bacterial pathogens is investigated. Respiratory infections predispose patients to co-infections and these lead to increased disease severity and mortality. Numerous types of antibiotics have been employed for the prevention and treatment of bacterial co-infection and secondary bacterial infections in patients with a SARS-CoV-2 infection. Although antibiotics do not directly affect SARS-CoV-2, viral respiratory infections often result in bacterial pneumonia. It is possible that some patients die from bacterial co-infection rather than virus itself. Therefore, bacterial co-infection and secondary bacterial infection are considered critical risk factors for the severity and mortality rates of COVID-19. In this review, we will summarize the bacterial co-infection and secondary bacterial infection in some featured respiratory viral infections, especially COVID-19.

In vitro antifungal susceptibility profile of Iranian Fusarium isolates: Emphasising on the potent inhibitory effect of efinaconazole compared to other drugs.

BACKGROUND: Fusarium species are opportunistic human pathogens that remarkably cause fungal infections ranging from superficial to fatal invasive disseminated infections. Fusarium species are notoriously resistant to the majority of antifungal agents. OBJECTIVES: Therefore, detailed studies regarding in vitro susceptibility are required and may lead to a better prognosis of severe infections. METHODS: We evaluated 25 antifungal drugs in vitro against 282 clinical and environmental Fusarium isolates. RESULTS: Fusarium species demonstrated high MICs/MECs values to the most commonly used antifungal drugs in clinical practice. The geometric mean (GM) MICs for luliconazole (0.004 µg/ml) and lanoconazole (0.012 µg/ml) were the lowest, followed by efinaconazole (0.98 µg/ml) and amphotericin B (1.04 µg/ml). CONCLUSIONS: Efinaconazole, a novel triazole, may be a promising candidate for the treatment of superficial Fusarium infections. Furthermore, the development of systemic formulations of these drugs as well as further in vitro and in vivo investigations could aid in the treatment of systemic fusariosis.

The role of serum circulating microbial toxins in severity and cytokine storm of COVID positive patients.

The emergence of Coronavirus disease 2019 (Covid-19) is a global problem nowadays, causing health difficulty with increasing mortality rates, which doesn't have a verified treatment. SARS-CoV-2 infection has various pathological and epidemiological characteristics, one of them is increased amounts of cytokine production, which in order activate an abnormal unrestricted response called "cytokine storm". This event contributes to severe acute respiratory distress syndrome (ARDS), which results in respiratory failure and pneumonia and is the great cause of death associated with Covid-19. Endotoxemia and the release of bacterial lipopolysaccharides (endotoxins) from the lumen into the bloodstream enhance proinflammatory cytokines. SARS-CoV-2 can straightly interplay with endotoxins via its S protein, leading to the extremely elevating release of cytokines and consequently increase the harshness of Covid-19. In this review, we will discuss the possible role of viral-bacterial interaction that occurs through the transfer of bacterial products such as lipopolysaccharide (LPS) from the intestine into the bloodstream, exacerbating the severity of Covid-19 and cytokine storms.

Effects of aflatoxin B1 exposure on sperm in rodents: a systematic review and meta-analysis.

Exposure to aflatoxin B1 can be associated with reproductive toxicity, accompanied by decreased sperm concentration in animal models. The aim of this meta-analysis was to determine the correlation between aflatoxin B1 exposure and sperm concentrations of male rodents (both mice and rats). According to inclusion and exclusion criteria, 8 articles were selected to assess in the current meta-analysis. The random effects and pooled analysis indicated that sperm concentration was decreased in mice [MD sperm = -20.79×106/sperm/g testis (95%CI =-1.3 to -50.5)] and in rats [-24.34×106/sperm/g testis (95%CI: -7.60 to -44.35)] after exposure to aflatoxin B1 compared with control groups. A significant heterogeneity was found among studies (for mice I2=99.7%, %, P<0.000 and rats =I2=98.8, P<0.000). The findings of present meta-analysis showed the association between aflatoxin B1 exposure and a decrease in sperm concentration in rodents.

In Vitro Antifungal Susceptibility Profile of Miltefosine against a Collection of Azole and Echinocandins Resistant Fusarium Strains.

Fusarium species are filamentous fungi that cause a variety of infections in humans. Because they are commonly resistant to many antifungal drugs currently available in clinical settings, research into alternative targets in fungal cells and therapeutic approaches is required. The antifungal activity of miltefosine and four comparators, amphotericin B, voriconazole, itraconazole, and caspofungin, were tested in vitro against a collection of susceptible and resistant clinical (n = 68) and environmental (n = 42) Fusarium isolates. Amphotericin B (0.8 µg/mL) had the lowest geometric mean (GM) MICs/MECs values followed by miltefosine (1.44 µg/mL), voriconazole (2.15 µg/mL), caspofungin (7.23 µg/mL), and itraconazole (14.19 µg/mL). Miltefosine was the most effective agent against Fusarium isolates after amphotericin B indicating that miltefosine has the potential to be studied as a novel treatment for Fusarium infections.

Fatal necrotising cutaneous mucormycosis due to novel Saksenaea species: a case study.

This case report describes the progressive wound infection in the left thigh of a 34-year-old man due to an old landmine explosion. The infection developed into rapidly spreading skin and soft tissue necrotising Saksenaea infection, despite antifungal therapy and surgical debridement. The report provides evidence that Saksenaea spp. should be added to the list of mucoralean fungi that can cause severe necrotising infection. It also highlights the need for improved early diagnostic procedures and enhanced understanding of Saksenaea virulence factors that contribute to necrotising infection.

Prevalence and concentration of fumonisins in cereal-based foods: a global systematic review and meta-analysis study.

Cereal-based foods are utilized as an essential food segment worldwide. Nevertheless, their contamination by mycotoxins, also fumonisins, could pose a critical health risk. The present research provides the first systematic review regarding the prevalence and concentration of fumonisins in cereal-based food with the aid of a meta-analysis. In this regard, some international databases PubMed, Web of Science, Google Scholar, and Scopus were explored during the last 30 years. Among 9729 screened articles, 73 articles (which meet the proposed inclusion criteria), including 11,132 data, were incorporated in the performed meta-analysis. The overall rank order regarding the concentration of fumonisins in cereal-based foods was corn-based foods > wheat-based foods > other cereal foods > barley-based foods > rice-based foods > oat-based foods. Based on the prevalence of fumonisins, the overall rank order was other cereal foods > corn-based foods > rice-based foods > wheat-based foods > oat-based foods > barley-based food. The present meta-analysis results can be a beneficial database for risk assessment model progress, which can help industries and organizations decrease the presence of fumonisins in cereal-based food.

Targeting novel genes for simultaneous detection of five fungal and bacterial agents from BAL samples using multiplex PCR assay.

The main purpose of our study was to evaluate multiplex PCR assay targeting novel genes for detection of five fungal and bacterial agents in BAL samples; because many fungi and bacteria that cause respiratory infections have similar clinical symptoms, diagnosing and differentiating them are therefore essential to controlling and treating them. A total of 100 BAL specimens from a mycobacterium and mycology laboratory were collected from patients suspected of having TB or other respiratory diseases. Novel DNA targets for Aspergillus, Nocardia, Cryptococcus, and Streptomyces were found using modified comparative genomic analysis. Afterward, the primers were designed based on novel targets, and the sensitivity and specificity of the newly designed primers were evaluated. These primers, along with specific primers for M. tuberculosis (SDR), were used in a multiplex PCR assay. The results showed the culture test to be more sensitive than the PCR assay in detecting M. tuberculosis. However, in the detection of Aspergillus, the PCR assay was more sensitive than the culture test. We also found one positive culture and two positive PCR assays for Nocardiosis. Cryptococcal infections and Streptomyces associated with lung diseases were not identified by the culture test nor by the PCR assay. The multiplex PCR is one of the cheapest molecular diagnostic tests readily available for BAL samples in clinical laboratories. This assay can be used for early reports of the causative agents and for treating patients with appropriate drugs at an early stage.

Potent Activities of Luliconazole, Lanoconazole, and Eight Comparators against Molecularly Characterized Fusarium Species.

A collection of clinical (n = 47) and environmental (n = 79) Fusarium isolates were tested against 10 antifungal drugs, including 2 novel imidazoles. Luliconazole and lanoconazole demonstrated very low geometric mean MIC values of 0.005 and 0.013 µg/ml, respectively, compared with 0.51 µg/ml for micafungin, 0.85 µg/ml for efinaconazole, 1.12 µg/ml for natamycin, 1.18 µg/ml for anidulafungin, 1.31 µg/ml for voriconazole, 1.35 µg/ml for caspofungin, 1.9 µg/ml for amphotericin B, and 4.08 µg/ml for itraconazole. Results show that these drugs are potential candidates for (topical) treatment of skin and nail infections due to Fusarium species.

Beta-tubulin gene in the differentiation of Fusarium species by PCR-RFLP analysis.

Fusarium species belong to one of the most important fungal groups in the medical, agricultural, and veterinary fields. This study aimed to evaluate the efficiency of PCR-RFLP analysis of the beta (ß)-tubulin region for differentiating Fusarium species. A total of 107 strains of Fusarium spp. were studied, including isolates from environmental, clinical, and reference sources. The ß-tubulin genes of all isolates were successfully amplified with primer pairs (T1 and T22). A PCR product of approximately 1400 base pairs was generated for each Fusarium sp. After evaluation of various enzymes, three restriction enzymes, namely Ban II, BsaWI, and HincII, were selected. Based on the selected enzymes, the isolated Fusarium spp. were categorized into 24 groups. In this study we were able to identify F. graminearum, F. culmorum, and F. cerealis through the proposed analyses as well as other pathogenically important species such as F. oxysporum and F. solani. Unlike all other similar previous studies, this study was able to differentiate among F. graminearum, F. culmorum, and F. cerealis. However, we were unable to differentiate F. armeniacum and F. acuminatum or F. sportrichioides from F. langsethiae. Hence, it is recommended that other genes must be evaluated to overcome the limitations of the ?-tubulin gene in differentiating the above species.

Identification of Aspergillus sections Flavi, Nigri, and Fumigati and their differentiation using specific primers.

Aspergillus species are important in medicine, agriculture and various industries. The sections Fumigati, Flavi, and Nigri are the most important members of the Aspergillus genus. This study intended to identify and separate these three Aspergillus sections and to differentiate among them using specific primers. A bioinformatics study was initially performed to analyse the sequences of five genes, namely, beta-tubulin, calmodulin, the pre-rRNA processing protein Tsr1, the DNA-replication licensing factor Mcm7, and RNA polymerase II second largest subunit (RPB2) in the three Aspergillus sections using MEGA6 software and the NCBI database. Primers were designed to select genes for each of the Aspergillus sections being analysed. A total of 134 environmental and clinical Aspergillus species were isolated, purified and initially identified by colony morphology.. Subsequently, DNA was extracted using the phenol-chloroform method, specific primers were synthesized, PCR was performed for DNA from all isolates, and the results were compared to morphological characteristics. Of the 134 isolates tested, 56 were Nigri, 32 were Fumigati, 32 were Flavi, and the rest (14 isolates) belonged to other sections. The beta-tubulin and calmodulin genes were found to be the most suitable for differentiating among these three groups; the beta-tubulin gene was used for molecular identification of Aspergillus section Fumigati, and the calmodulin gene for identifying sections Flavi and Nigri.

Giberella fujikuroi species complex isolated from maize and wheat in Iran: distribution, molecular identification and fumonisin B1 in vitro biosynthesis.

BACKGROUND: Contamination of food and agricultural crops by Fusarium species is a major concern of food spoilage and a potential public health hazard. In the present study, natural contamination of maize and wheat samples from main cultivation areas of Iran by Fusarium species belonging to the Giberella fujikuroi species complex was evaluated, with special attention to the ability of the isolates to produce fumonisin B1 (FB1 ). RESULTS: A total of 55 Fusarium isolates were obtained from 27/32 maize samples (84.4%) and 11/15 wheat samples (73.3%). They were identified as F. verticillioides (47.3%), F. proliferatum (47.3%), F. fujikuroi (1.8%), F. nygamai (1.8%) and F. redolens (1.8%) by sequence analysis of translation elongation factor 1-α (TEF1-α). Twenty-two of 55 Fusarium isolates belonging to F. proliferatum (23.6%), F. verticillioides (14.5%) and F. fujikuroi (1.8%) produced FB1 in the concentration range 230.4-9565.0 µg mL(-1) . The dendrogram resulting from the TEF1-α profile showed that the genotypes were divided into clusters I, II and III, of which cluster III contained only F. redolens, its first report from Iran. CONCLUSION: On the basis of in vitro FB1 biosynthesis of the analyzed strains, the high degree of contamination of maize and wheat with Fusarium strains reported here should be considered as a potential public health threat, because a meaningful number of the isolates were found to produce hazardous levels of carcinogenic FB1 .

A qualitative and quantitative study monitoring airborne fungal flora in the kidney transplant unit.

BACKGROUND: Solid organ transplantation patients are at high risk for opportunistic air-borne fungal infections due to using the potent immunosuppressive agents. OBJECTIVES: The current study aimed to qualitatively and quantitatively evaluate the fungal flora present in the air of Kidney transplant unit of Baqiyatallah hospital. MATERIALS AND METHODS: In this prospective study, air samples from patient room, baths site, ICU and isolated room, corridor site and outside the ward were obtained by settled plate technique using plates containing Sabouraud's dextrose agar medium. In the current study, 36 agar plates containing Sabouraud dextrose agar medium were used. The plates were exposed for 20 min at height of 100-150 cm above the ground in units of hospital. Immediately after collection, samples were incubated at 27 ± 2ºC for four weeks. The slide culture method and Lacto-phenol cotton blue were used for definitive identification and staining fungal cultures, respectively. RESULTS: The mean of colony forming units (CFUs) on indoor and outdoor plates was 6.6 ± 1.3 and 6 ± 1.9 / plate respectively. Statistical analysis showed that the observed difference is not significant. Also, the results showed that the mean of CFUs in the air of patient's rooms (6.8 ± 1.7), halls (4.5 ± 1.7), bathrooms (6.8 ± 1.5), and ICU rooms (3.2 ± 1.8) were not significantly different. The mean of different fungal genera isolated from indoor and outdoor plates were 1.9 ± 0.2 and 4 ± 0.5 genera/plate respectively, that indicates significant difference between indoor and outdoor air quality (P < 0.001). CONCLUSIONS: Lack of difference between quantity of outdoor and indoor air fungi indicates inefficiency of air control measures, and indoor lower genus diversity compared to outdoor air shows that there may be conditions that facilitate fungal growth in the environment of kidney transplantation unit.

A duplex PCR for rapid and simultaneous detection of Brucella spp. in human blood samples.

OBJECTIVE: To design a duplex PCR for rapid and simultaneous detection of Brucella species. in human blood samples. METHODS: Fifty-two peripheral bloods samples were collected from suspicious patients with brucellosis. Following DNA extraction, PCR assay were performed, using three primers that could simultaneously identify and differentiate three major species of pathogenic Brucella in humans and animals. RESULTS: Of the 52 peripheral bloods samples tested, 25 sample (48%) showed positive reactions in PCR. Twelve samples were positive for Brucella abortus 39 (B. abortus 39) (23%), 13 for Brucella melitensis 39 (B. melitensis 39) (25%) and 0 for Brucella ovis 39 (B. ovis 39) (0%). CONCLUSIONS: This work demonstrates that in case where specific primers were utilized, duplex PCR has proved to be a simple, fast, and relatively inexpensive method for simultaneous detection of important species of Brucella in clinical samples.

Simultaneous detection and differentiates of Brucella abortus and Brucella melitensis by combinatorial PCR.

OBJECTIVE: To evaluate simultaneous detection and differentiates of Brucella abortus (B. abortus) and Brucella melitensis (B. melitensis) through the combinatorial PCR method. METHODS: This study was designed using three primers that could simultaneously identify and differentiate two major species of pathogenic Brucella in humans and animals. Identification and differentiation of each species using the size of the PCR product were determined. To determine the specificity of the method, bacteria close to the genus Brucella were used. Finally, to confirm PCR products, In addition to the products sequence, RFLP was performed on PCR products using restriction enzymes. RESULTS: The method of optimized combinatorial PCR in this study could simultaneously detect and differentiate B. abortus and B. melitensis with high specificity and sensitivity in clinical samples. Differentiation of species is based on the resulting bands; therefore, the band 494 bp for B. abortus and 733 bp for B. melitensis were obtained. RFLP and sequencing results confirmed PCR results. CONCLUSIONS: The results of this study shows that without routine diagnostic methods such as culture and serology tests, using the molecular method of combinatorial PCR, important species of Brucella can be simultaneously identified and differentiated in clinical samples.