JOURNAL OF MICROBIOLOGY KNOWLEDGE
Year:2010 | Volume:2 | Issue:5|Papers Count:11

Many Bacteria cause contamination in food products. Salmonella is the most common of them, because of different serotypes and variety of hosts and carriers. A total of 60 Salmonella strains were isolated from food products suspected to contamination by Salmonella and were analysed to determine their drug resistance pattern and transfer of resistance factor, via conjugation. Antimicrobial resistance determining was performed by Kirby - Bauer disk diffusion method according to the NCCLS criteria. MIC was done using Macrodilution Method. To consider the transfer of antibiotic resistance factor, conjugation by mixed culture method was carried out. The highest resistance was found against tetracycline, trimethoprim sulfamethoxazole and nalidixic acid. Multiple drug resistance was showed in 91.66% of strains. The rate of MIC was between 0.5-512 microgram per millilitre. After adjoining recipient bacteria and Salmonella strains as donor bacteria, the transfer of antibiotic resistance factor was carried out from Salmonella to E. coli for six antibiotics. By using E. coli DH5 a F- Lac+ Nalr as recipient strain, the highest percent of resistance transfer was related to tetracycline (44.44%), followed by trimethoprim sulfamethoxazole, choloramphenicol, ampicilin, cefalexin and cefotaxim. By using E. coli C1180 as recipient strain, the highest percent of resistance transfer was related to trimethopnim sulfamethoxazole (50%), followed by tetracycline, chloramphenicol, cefotaxim and cefalexin. In this study, Salmonella sp. isolates showed high percentage of resistance to drugs used. Multiple drug resistance which is plasmid - born in most cases and is transmitted via conjugation, has produced problems. To limit using antibiotics in human and animals, performing antimicrobial susceptibility tests to select a suitable antimicrobial agent, application of recommended dosage regimens and duration of therapy may decline the extent of resistant bacteria.

Many of Bacteria and Fungi are identified to common factor as nosocomial infections by using utensils such as venous catheter and urinary catheter, but investigation on other hospital biofilm of utensils have not been done. The aim of this study was identification of bacteria and fungi in hospital biofilms of utensils. In 1387-1388, utensils of Shahid Fahmide children hospital of Tehran such as Nasal sond, Oxygen hood, Ambo bag, Catheter and so on were shaved by strilized surgical blades. A sample was isolated for identification of bacteria and another sample was isolated for fungi. The resistance bacteria against antibiotic were determined with disk diffusion method. 192 samples were collected from biofilms of hospital utensils and Staphylococci epidermidis (%54.6), Staphylococci saprophiticuc (%23.4), Staphylococci aureus (%4.1), E. coli (%14.5), Pseudomonas aeruginosa (%14.5), Klebsiella pneumoniae (%7.2), Entrobacter sp. (%4.1) and Proteus mirabilis (%3.1) bacteria and A. niger (%56.7), A. flavus (%19.7), Paecilomayces sp. (%7.2), Penicillium sp. (%6.2), Fusarium sp. (%4.1), Alternaria sp. (%4.6), Aerobasidium sp. (%2.6), C. albicans yeast (%2), Hendersonella sp. (%1.5) and Celadospurium sp. (%0.5) fungi were isolated and identified. Maximum resistance of gram positive bacteria was to Penicillin and Amoxicillin (%100), but maximum resistance of gram negative bacteria was to cephalexin and tetracycline. According to increasing problems of bacteria which are resistant to drugs on necessary hospital utensils that are used commonly, antibiogram test must do for each patient. Actions that are taken to control infection and careful hygienic consideration and restriction of using antibiotic can prevent the spread of bacteria resistant. There was a relation between fungal and bacterial contamination utensils and seasons (P<0.001).

Asteraceae family due to compounds such as flavonoids, Saponyn, steroids, alkaloids and glycosides are a lot of attention. Effective compounds in this family are sesquiterpen major metabolites which are considered responsible for the antimicrobial activity. In this study of antibacterial extracts ethanol, methanol and aquatic extracts are produced from the aerial organs (stem, leaf), flowers and roots of the two species of Aster tartaricus L. and Rhudbeckia hirta L. Some microorganisms such as, Kelebsiella  pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, E. coli, Bacillus anthracis and Streptococcus pyogenes were evaluated. The methods are used in this survey include measuring the growth inhibition zone diameter and MIC. The results showed that methanol and ethanol extracts have more inhibition effect than extract aquatic on microorganism. The ethanol extract prepared from various parts of plants and it showed that has more effect than methanol extracts on the growth of microorganisms. Between the two species in three parts plant, Aster tartaricus flowers, shoots and roots has been with more inhibition effect on microorganisms.

Fungal infections are considered a major problem in the developing countries and common drugs for treatment are also toxic and expensive or have side effects. The purpose of this study is introduction of a new antifungal plant drug for treatment of fungi diseases, which have not yet an ideal treatment, such as dermatophytosis. For invitro study, First, Myrtus Communis leaves were gathered, then dried and powdered. Extracting was done by percolation with solvents, Ethanol, Chloroform, N-Hexane and Petroleum Benzine. Then, various dilutions 30-600 mg/ml and 0.5-4 mg/ml extract were used on those fungi by Broth Dilution method and fungi growth was studied and MIC and MFC of those fungi were determined. The drug clotrimazole was used as a control for lack of growth in order to comparing it as a chemical drug with the mentioned extract. The dilution of 30-600mg/ml whole extract did not allow fungi trichophyton menagrophytes and Microsporum canis and Epidermophyton Fluccosume to grow, but it was not effective on fungi candida Albicans and Aspergillus Niger. Other fractions Chloroform, N-Hexane and etherdipetrolic also had not effect on any of the fungi. But at lower dilution for whole extract of Myrtus Communis, MIC for fungus Tricophyton Mentagrophytes was 1.5 mg/ml and for Microsporum Canis was 1mg/ml and for Epidermophyton Floccosume was 1mg/ml. With respect to effectiveness of hydroalcoholic whole extract of Myrtus Communis on fungi Tricophyton Mentagrophytes and Epidermophyton Floccosume and Microsporum Canis, it is recommended to use this extract for treatment and eradication of these fungi.

Background: Primary infection of herpes simplex virus’ especially in first and second trimester of pregnancy causes severe tissue injury and congenital abnormalities. Infection in third trimester of pregnancy has a higher chance of transmission but less tissue injury. Elisa method is simple test for detection of serum antibody. In this research, Elisa method used for detection of anti Herpes simplex antibody in maternal blood was investigated. In this study, 5 ml of blood obtained from mothers that aborted her fetus then serum antibody titrated with Elisa method. In this study, 118 cases of abortion included, 34 cases (29%) had recurrent spontaneous abortion but in 84 cases (71%) abortion was occurred for the first time. Five cases in Elisa test, showed IgM anti herpes simplex virus antibody. Results of this study showed that active infection of herpes simplex virus may relate to abortion.

Cryptococcus neoformans is encapsulated opportunistic yeast which usually affects the individuals with immune deficiency but can also cause disease in healthy individuals with a worldwide distribution. Infection emerges following inhalation of fungi and meningitis is the common clinical form of the disease. There are several common methods for the diagnosis of this factor, but none of these methods have acceptable sensitivity, specificity and speed. Molecular methods like PCR have appropriate sensitivity, specificity and speed that can be relied on as a suitable method in the diagnosis of Cryptococcus neoformans. Cerebrospinal fluid samples of 140 suspicious patients to meningitidis which were collected from a total of 5 hospitals were cultivated, stained and PCR was performed. A sensitive PCR using primers ITS1 and CN4 and 16S rRNA as target gene was designed and used on cerebrospinal fluid samples collected from patients. Culture and staining (Indian ink) of all samples were negative. In one sample (related to HIV-positive patient who was suffering from meningitis), PCR result was positive. Current molecular detection limit was assessed as 10 organisms per ml Cryptococcus neoformans. Specificity test was performed with different species of Candida and Aspergillus, as well as common bacteria causing meningitis and no product was proliferated. This study indicates that PCR is a sensitive and reliable method for rapid diagnosis of Cryptococcus neoformans in cerebrospinal fluid samples.

The type of anoxygenic phototrophic bacteria recognized. Owing to the presence of photosynthetic pigments, cell suspensions appear in various colors according to the use of this bacteria, the productions of biotechnology and different industrial, so the isolation of them are important. But they have grown slowly, however there is difficult situation to produce of anaerobic – condition a long time whenever has no reports according to isolation of these bacteria in Iran. In the study, use of the Water, in from 15 Khordad dam’s residue in Qom province, displayed colorful - layers in Winogradsky column. In order, to separate and purity these bacteria, an appropriate ready made liquid and solid (Pfennig) setting were used and put against the direct sun light and fit temperature and anaerobic - condition, so the isolations grew after 1-2 months. Firstly (light and electronic) microscopic and macroscopic isolation were analyzed. We found colonies purple-colorful without special smell, purl smooth and buttery of these bacteria in plate, and then isolations were colored with gram and sodan. The out come of the microscopic colorful-layers can be considered as the confirmation of the existence of gram-negative bacillus and PHB granules. More ever the result of the electronic-microscope (TEM) brings out the presence gas vacuole, Mesosomes wrinkle and stored granules. The 16SrRNA tests did for wistful of recognization the species of these bacteria. As a result of mentioned two levels, show in which they are 4 species purple nonsulfur bacteria that is in α-proteobacteria. Finally the species of Rhodobacter, Rhodomicrobium and Rhodopseudomonas, recognized.

Air containing a large number of microbes that inclined to several factors such as smoke, particulate organic and inorganic, precipitation area, moisture and dust .Smoke attract a numbers of microbes to its. Microbes are rarely found in areas covered with snow and ice. Also, microbes enter from different soils and animals into air. Bacteria, Actinomycets and fungi often are in the air. Air contamination in the hospital is several times more important to other places, because sometimes lead to death of patients admitted in hospitals. Hence should try to avoid of contamination of hospital air to be using of air ventilation and sanitation.