International Journal of Molecular and Clinical Microbiology
Volume:10 Issue: 2, Summer and Autumn 2020

Stress has been suggested to play an important role in the pathogenesis of gastric damage by either acting as a predisposing factor or a primary factor. Arcobacter species have frequently been isolated from stomach ulcer cases of pigs, but the role of these agents in the pathogenesis of the disease remains unclear.The primary aim of the present study was, to reveal the role of Arcobacter butzleri and stress in the etiology of gastric damage by establishing an experimental mouse design. Infection was induced by intra-gastric gavage of A. butzleri in two experimental groups comprising five weeks old specific pathogen-free (SPF) Balb/c mice. At 1, 2, 3, 4, and 7th weeks of the experiment, the animals were euthanized and examined for lesions occurring in the stomach. Histopathology, culture, and Polymerase Chain Reaction (PCR) were employed to detect development and severity of lesions and pathogens. In addition, serum corticosterone levels indicating the presence of stress in the mice were investigated by an ELISA method. Microscopic examination showed that the stomach of the experimental group had inflammatory reactions to varying degrees, but ulcers were not observed in the gastric mucosa of the animals exposed to A. butzleri and stress groups. The results suggested that A. butzleri and stress were predisposing factors in the formation of gastric ulcer, but failed to provide evidence for their causative role.

Fire blight, caused by Erwinia amylovora, is one of the most important diseases of fruit trees worldwide. The aim of this study was to isolate and identify rhizospheric and endophytic bacteria with antagonistic activity against Erwinia amylovora in apple and pear orchards around Gorgan, Golestan province. Root, leaf and rhizospheric soil samples were cultured on nutrient agar medium and after incubation morphological features of the appeared colonies were examined. The antagonistic activity of the isolates was determined by well diffusion agar. Chloroform test was used to evaluate the production of antimicrobial agent by antagonist isolates and catalase and protease sensitivity tests were used to determine its nature. The thermal stability of the antimicrobial agent and the effect of pH on its inhibitory activity were also evaluated. Isolates with more antagonistic activity were identified based on 16S rRNA sequencing. Fourteen isolates produced antimicrobial substance with antagonistic activity, which had a nature other than hydrogen peroxide. The antimicrobial agents from 8 isolates were proteinaceous in nature. The inhibitory activity of cell-free supernatant of these isolates was inactivated at 100 °C and had the best effect at neutral pH. The isolates identified by molecular method had a more than 90% similarity to Bacillus subtilis strain B-12, Bacillus subtilis strain YL-3, Paenibacillus polymyxa strain DST34, Pantua aglomrans strain ACBP1 strain. In the present study, bacteria with antagonistic activity against E. amylovora were isolated from rhizosphere and endophyte, but to better judge their performance, more tests are needed in different conditions.

Leeches have been used to complement medical therapies for many years, however there is little data on the microorganisms they may harbor as part of their flora. The study aims were to (1) identify the presence of bacteria and (2) the presence of Hepatitis B and C viruses (HBV and HCV) in medicinal leeches using traditional bacteriological assays, Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) and quantitative PCR (qPCR). Samples obtained from the body surface, intestine, and jaws from 10 Hirudo verbana leeches were aseptically cultured using traditional microbiological assays. Bacterial isolates were identified using the MALDI-TOF technique and the presence of HBV and HCV was analyzed using qPCR. The primary bacterium isolated from the sampled leeches were Aeromonas veronii (A. veronii) which was isolated from the jaws, gut and body surface of all leeches. Other bacteria isolated at a lower frequency from various parts were Chryseobacterium gleum, Ochrobactrum anthropi, Moraxella osloensis, Microbacterium oxydans, Kytococcus sedentarius, Rhizobium radiobacter, Staphylococcus hominis, Citrobacter and Bacillus. No anaerobic bacteria or hepatitis viruses were detected. Interestingly, some of the bacterial species identified in this study have been implicated in hospital acquired infections and are of particular risk to immunocompromised patients. The recovery of potential human pathogens from within medicinal leeches is a public health concern and consequently their use should be restricted and avoided in susceptible individuals or a prophylactic treatment should be applied.

Lactose indigestion is a common issue since long around the globe. This study involves determination of lactic acid bacteria role during pathogenic infection. The lactic acid bacteria from dairy products are isolated using MRS media to determine their beneficial and harmful effects on growth of pathogenic microorganisms. The lactic acid bacteria include lactose fermenters specifically lactobacillus spp. Eight isolates were tested to determine their antimicrobial activity against pathogens. The zone of inhibition ranges from 11-18mm by lactobacillus spp. (Lactobacillus casei, Lactobacillus salivarious, Lactobacillus brevis, Lactobacillus acidophilus, Lactobacillus bulgaris and Lactobacillus plantarum).This gives the susceptibility pattern against the pathogens(Salmonella typhi, Helicobacter pylori, Staphylococcus aureus, and Pseudomonas aesuginosa).84% of the isolates show the susceptibility pattern against pathogens.The lactic acid bacteria boost the immunity by secreting extracellular antimicrobial products in competitive hostile environment.Thetreatment through antibiotics can be alternated by probiotics intake. This will also avoid pathogenic microorganism to become resistant that is enigma in pharma industries.

Aspergillus fumigatus is an opportunistic fungal pathogen causes invasive aspergillosis in immunocompromised patients. Raphanus sativus L. var. niger and Trachyspermum ammi are two medical herbs which seemed to have an antifungal activity that can be integrated alternative medicine into conventional medicine. The aim of study was to evaluate the effect of R. sativus and T. ammi on the resistant and susceptible A. fumigatus isolates.In present study, 185 environmental samples from 11 cities of Iran were processed and screened in terms of azole resistance using selective plates. The isolates were confirmed by partial sequencing of the b-tubulin gene. Afterwards, in vitro antifungal susceptibility tests against triazole agents and R. niger and T. ammi extract were performed based on the CLSI, M38-A2 document. The ingredients in the extract by gas chromatography method were isolated and identified by mass spectrometry. Overall, 51 A. fumigatus isolates were detected. According to in vitro antifungal susceptibility tests, 45 A. fumigatus isolates had high MICs of itraconazole (≥8 mg/L) and voriconazole (>2 mg/L) and 6 A. fumigatus isolates were susceptible. The MIC 50 and MIC 90 for R. sativus was 1.95 mg/ml and 3.9 mg/ml respectively. Also, The MIC 50 and MIC 90 for trachyspermum ammi was recorded as 2.30 mg/ml and 4.85 mg/ml respectively. The main identified compounds were Tramadol (58.37%), Butanol (23.42%), Benzofuran (18.21%). Our results indicated that R. sativus and T. ammi extracts significantly inhibited the growth of A. fumigatus isolates and have an appropriate antifungal activity.

Saline water wetland ecosystems such as Alagol, Almagol and Ajigol are located in the vast Turkmen-Sahra plains (Golestan prov.) in east of Caspian Sea are one of the most sensitive ecosystems. Samples were isolated for 4 months from different areas with different EC and pH of the mentioned wetlands, seals and geysers. A total of 70 different water samples were collected from aquatic ecosystems that were purified by culturing on selected media. According to biochemical tests, 41 isolates were able to grow in saline environments, of which 63.4% were halophiles, which were observed only in wetlands and geysers. The other 36.6% were halotolerant and were excluded from the results. Alagol wetland had the highest abundance in halophilic species. . The enzymatic activity of halophiles for amylase, protease and lipase hydrolase showed that 34.6% of the isolates contained all three enzymes, which include all three groups of gram-positive cocci, gram-positive and gram-negative cocci. Comparison of enzymatic activity also showed that with the exception of two extreme species of Halophilus bacillus subtilis which were relatively slower in growth and had a longer period at the beginning and end of substrate application in culture medium, the rest of the isolates had almost the same range during growth. They have the time of enzyme production and the time of completion of the substrate.

Making cheese is simply a process of turning a liquid (milk) in-to a solid. Rennet has an important role in this process which is a complex set of enzymes where chymosin is the key component. The aim of this study was identifying the Bacillus genus with the ability of producing the enzyme. 50/75 isolates from soil of Gandom Beryan area of Kerman, Iran, determined as bacillus spp via classical and PCR methods. The presence and over production of the cltA gene (encoding chymosin) were investigated by performing cloning in Escherichia coli (E. coli) origami and functional cloning confirmed by using real-time reverse transcription –polymerase reaction (Real- time PCR) and clonal selection. The results showed functional cloning of the gene in Escherichia coli origami. Among 50 isolates of Bacillus spp, 4 isolates (8%) showed the capacity to produce the gene. Phylogenetic characterization analysis of 16S rRNA gene of the Bacillus spp determined the strains as Bacillus cereus. According to the results of this study, expression of the gene via Real-time PCR showed their ability to produce clt A gene and rennet. Although to further confirmation, a larger samples needs to be performed and additional tests are required. Due to animal rennet deficiency, determining such accessible and cheaper sources in producing rennet is important.

L-asparaginase is an enzyme that catalyzes the hydrolysis of l- asparagine to aspartic acid and ammonia. It is currently used for the treatment of leukemia and some tumors. L-asparaginase decomposes L-asparagine and deprives cancer cells from this amino acid. This study aimed to isolate and identify the native L-asparaginase producing bacteria. To isolate l-asparginase-producing bacteria, 30 soil samples were collected from forests in west of Mazandaran. The soil samples were cultured in the M9 culture medium and then screened. Bacteria with the highest enzymatic activity were identified through 16S rRNA gene sequencing. The enzymatic activity was measured by the nesslerization method. Two isolated bacteria, namely Enterobacter cloacae and Citrobacter spp. Showed the highest enzymatic activity of 10.156 and 74.843 U/mL, respectively. The optimal conditions for enzymatic activity of the identified bacteria are similar to the physiological conditions of the human body indicating the need for complementary studies on asparaginase to achieve an effective enzyme.

Rabies is zoonotic acute encephalitis that continuously kills thousands of people annually with almost 100 percent fatality. In the present study, apoptosis was investigated in BHK- 21 cell lines infected by rabies virus. Apoptotic cells are identified by fragmented and dense chromatin masses and evaluated by microscopic and statistical methods. In vitro apoptosis was time and dose-dependent in 24 to 72 hours of incubation in BHK-21cell lines; however, a marked reduction in the number of apoptotic cells was observed, especially at the lowest concentrations of F4 and F5 fractions, obtained by FPLC of crude Naja naja oxiana venom. The number of infected apoptotic cells in the presence of different concentrations of two fractions F4 (40, 30 and 20μg/ml) and F5 (40, 25 and 15μg/ml) of Caspian cobra venom are obtained by Hoechst staining. According to the obtained results, by decreasing the concentrations of F4 and F5 fractions, the apoptotic indices were decreased in each incubation time. The F5 fraction in comparison with F4 at the same incubation times (24, 48 and 72h) showed more effective on apoptosis of infected cells. The highest percentages (66.57% and 65.43%) of apoptotic cells which were recorded after 48 and 72 hours belong to 40μg/ml of F5 fraction respectively. Our observations have shown that the use of a specific fraction (F5) of cobra venom, in an efficient concentration and time can cause apoptosis of rabies-infected cells, so it can be hoped that this toxic fraction will be a candidate in treatment of Rabies virus proliferation.

Candidiasis is one of the serious opportunistic fungal infections caused by different species of Candida, especially Candida albicans. The extracellular enzymatic activities are determined as principal factors for pathogenesis of Candida spp. involved in the degradation of proteins and adhesion during biofilm formation. The study was performed on 100 Candida isolates prepared from patients with various forms of Candidiasis, referred to the Laboratory. All isolates were confirmed by phenotypic methods. The evaluation of enzyme activity of (including to proteinase, hemolysin , phospholipase and esterase) different of Candida spp. was done in chromogenic media. In addition, the biofilm formation of all isolates was done by MTT method. Our results indicated the proteinase activity was positive (mean 0.015), hemolysin activity was positive (mean= 0.027), phospholipase activity was positive (mean=0.52) and esteraseactivity waspositive (mean=0.003). The highest and lowest biofilm formation were seen in in C. glabrata with (OD=0.62) and C. tropicalis with (OD=0.46), respectively. The secretion of several enzymes by Candida isolates has been identified for their virulence factors in candidiasis. Our data recommend that biofilm formation is probably to key a role in the pathogenicity of candidiasis, and in patients with immunocompromised, this might be due to the capability of C. albicans to adapt to the changed physiological environment.