robab baharvand

Fine dust includes dust and particles suspended in the air, which reduce visibility and have different origins. The present study aimed to investigate the abundance of air bacteria during micro dust storms in Lorestan province using classical methods.

In this study, sampling was performed in three cities of Lorestan province. Air bacteria were isolated by classical methods, and data analysis was carried out using the Chi-square test. The relationship between the abundance of bacteria and meteorological parameters was investigated and analyzed by Spearman's correlation coefficient test.

The results of the present study demonstrated that 96 colonies grew on the TSA medium. Moreover, %55.2 of these colonies were bacteria, and %44.8 were yeast. Poldakhtar and Khorramabad stations showed the highest (%25) and lowest (%8.33) frequencies. On the R2A medium, 184 colonies grew. In addition, %69 of these colonies were bacteria, and %31 were yeast. Kohdasht and Khorramabad stations had the highest (%34.8) and lowest (%4.3) frequencies. In TSA and R2A environments, the most and least frequently observed isolates were Bacillus and Actinomycetes, and the highest microbial frequency was related to Kohdasht and Poldakhter. According to Spearman's correlation test, there was a direct relationship between the amount of fine dust and the abundance of bacteria (P=0.637, r=0.026), and a significance inverse linear relationship was observed between wind speed and the number of colonies (P=0.048, r = -0.569).

Bacterial abundance was higher in the R2A medium. The dominant bacteria in the TSA environment were Bacillus and Micrococcus, and in the R2A environment, Bacillus and Corynebacterium. The results pointed out that the amount of fine dust and wind speed have an effect on the abundance and diversity of air bacteria.

Backgrounds and Listeria is a gram positive bacterium، facultive intracellular pathogene. prf A gene has an important role in virulence. The purpose of this study was to determine of the presence of Listeria monocytogenes in various meat products and presence of prf A gene in bacteria isolated from food samples and compare them with clinical samples and standard samples. During 6 months of 60 samples of beef، chicken، ham، cocktail، sausage، from a butchery’s Khoramabad and shops in Khoramabad and Tehran were collected. L. monocytogenes was isolated according to cold enrichment method and prf A gene were analyzed by PCR (Polymerase chain reaction) method. Statistical analysis was performed with the software SPSS (Statistical package for social science). From 60 samples of meat and meat products، 8 (%13. 3) were positive for Listeria spp. Among in these samples، 4 cases of L. monocytogenes (% 6. 6)، 3 cases (%5)، L. innocua and 1 case (%1. 6) L. welshimri، were isolated which L. innocua was isolated from meat and poultry samples and L. monocytogens from meat، chicken، ham and L. welshimeri from meat were isolated. Prf A gene was detected in isolated L. monocytogenes and donated bacteria from dairy products، clinical and standard samples، 2 cases of donated samples of vegetable contained prf A genes. The prf A gene (activator of transcription and regulators the expression of other virulence genes)، in the studied samples were observed. This gene plays a role in pathogenesis. Because these bacteria are transmitted through food and is a serious threat to public health. Thus identification of bacteria especially its genes could be possible to find some ways to prevent the bacteria and avoid disease from it.