حمید کاظمیان

Profitability of sheep in terms of meat production largely depends on growth traits and carcass characteristics. Despite the importance of the quality of sheep meat, few researches have been conducted in this field in the native sheep of the country. Therefore, the importance of examining the characteristics of animal carcasses, especially when they are still alive, is evident. The aim of the present study was to investigate the genetic and phenotypic relationship between biometric traits, body weights and carcass traits measured by ultrasound in Kurdi sheep of North Khorasan. Since the measurement of carcass traits is difficult and expensive, and in order to better design breeding programs to improve carcass traits, if there is a strong genetic relationship, it is possible to replace traits that are easier to measure with carcass traits that are difficult to measure.

The data of 658 Kurdi sheep in the Shirvan Kurdish sheep breeding and breeding station located in North Khorasan province in the northern area of eastern Iran between 57 degrees east longitude and 37.4 degrees north latitude in the spring, summer and autumn seasons of 2021 were used. The information related to pedigree and birth weights (658 records), three months (652 records), six months (638 records) and nine months (419 records) were extracted from the records recorded in the said station. General linear models (GLM) procedure of SAS software was used to investigate fixed effects on traits. To estimate the parameters and the genetic relationship between the mentioned traits, the restricted maximum likelihood (REML) method was used based on single and two traits animal models in WOMBAT software. Multivariate regression was used to obtain the prediction equation of carcass traits based on other studied traits.

Heritability of subcutaneous fat thickness, area, width and depth of ultrasound longissimus muscle were estimated as 0.1±0.06, 0.06±0.06, 0.10±0.03 and 0.08±0.03 respectively. A high positive genetic correlation was observed between subcutaneous fat thickness and longissimus muscle area (0.71±0.31). Ultrasound carcass traits had a high positive genetic correlation with tail traits. A high positive genetic genetic correlation was found between ultrasound carcass traits and height of the withers, height at rump, heart girth, belly circumference, body diagonal length, thigh circumference and rump depth. The model related to longissimus muscle area with the highest coefficient of determination (0.82) is more reliable than other models for prediction.

The low heritability of traits measured by ultrasound technology in Kurdi sheep of Shirvan Kurdi sheep breeding station showed that improving these traits through individual selection is not very effective and other selection methods (family selection or marker-assisted selection) should be used for improvement of these traits. Generally, due to relatively high coefficient of determination, regression models can be used to predict carcass traits in the flock of Shirvan Kurdi sheep station.

The genome of the bacteria has considerable diversity in terms of sequence of nucleotide bases and change over the time. With the advancement of bioinformatics science possibility of the vast comparison to living organisms has risen. During the last two decades many information about genome sequencing of pathogenic and non-pathogenic bacteria have been published. Using this information and to find connections between them and many phenotypic characteristics and behavior of bacteria could be used in many studies. In this study we compared some of the genetic, phenotypic and behavioral properties of archaebacteria and eubacteria.
In this analytical study, genomic Information of 286 species of archaebacteria and 122 species of eubacteria were collected from the NCBI (National Center for Biotechnology Information) site which was conducted in April to June 2015. Mean of gene size, gene number, protein number and C content compared in the two groups of archaebacteria and eubacteria. Association of genomic characterization of bacteria with several other characteristics were analyzed using SPSS statistical software version 19 (Chicago, IL, USA). For this purpose, the Pearson correlation coefficient (Pearson), Student’s t-test and ANOVA test (One-way analysis of variance) was used. The P values less than 0.05 was considered as significant level.
There was significant association between means discrepancy in two group (P= 0.01). The genome size of eubacteria and archaebacteria have significant association with some of the characteristics of bacteria, such as the C content, the number of proteins, genes and habitats of the bacteria (P= 0.01). As well as there was significant association between genome size and features such as number of pseudogene, mobility and type of breathing in eubacteria (P= 0.01) but not in archaebacterial (P˃ 0.05).
Many characteristics of eubacteria and archaebacteria are significantly associated with genomic properties. Comparison genomics of bacteria will help in identification of evolutionary origins as well as differences between different categories of bacterial.

Increasing frequency of Staphylococcus aureus infections and changes in antimicrobial resistance pattern have led to renewed interest in the use of lincosamide– streptogramin B (MLSB) antibiotics for treatment of infections. Since no study has focused on the molecular epidemiology of community -acquired staphylococcus aureus isolates in Iran، the aim of this study was to determine the molecular typing and prevalence of the macrolides-lincosamides-streptogramins B (MLSB) resistance in community associated s. aureus isolated from healthy students at Arak university of Medical sciences. 568 healthy students from Arak university of Medical sciences were subjected to this study. All samples were subjected to S. aureus–specific isolation procedures. D test was performed to determine various phenotypes as well as spa typing done for molecular typing of these strains. Of 568 the 84 community acquired Staphylococcus aureus، six (7%) were Methiclicin resistant Staphylococcus aureus (CA-MRSA) and 78 (93%) were Methicillin sensitive Staphylococcus aureus (CA-MSSA) of the 84 s. aureus strains، eight (9. 5%) showed constitutive resistance with spa type t660، t701، t304، t5598، t012، t3204، t084 and t1944. Two strains (2. 5%) demonstrated inducible resistance with spa type t9024، t077، two strains (2. 5%) were D test negative with spa type t084 and t1149. 72 (85. 5%) strains. Illustrated susceptible Phenotype. Among CA-MRSA isolates، two strains had constitutive resistance and four remaining CA-MRSA had susceptible phenotype The result of this study indicates that in community associated s. aureus strains، constitutive MLSB resistance rate is higher than the rate of inducible resistance. Presence of inducible resistance to clindamycin in CA-MRSA strains، warrants that D test should be performed to detect this type of resistance. All isolates with inducible and constitutive resistance and D zone negative strains had different molecular typings.

ß-lactamase enzymes are the most important factor for antimicrobial resistance in Gram-negative rods. This study aimed to determine the antimicrobial susceptibility pattern and the occurrence of AmpC ß-lactamase genes in clinical isolates of Klebsiella pneumoniae (K. pneumonia). A total of 100 K. pneumonia isolates was collected from clinical specimens obtained in the Vali-Asr hospital، Arak، Iran. The isolates were identified on the basis of standard biochemical tests. Antimicrobial susceptibility pattern was defined by the standard disk diffusion method according to CLSI (Clinical and Laboratory Standards Institute) guidelines. Plasmid-mediated AmpC β-lactamases genes were detected by using polymerase chain reaction (PCR) method. Of the 100 isolates tested، 19 (19%) were demonstrated to harbor AmpC β-lactamases by multiplex PCR; eight isolates carried β-lactamases genes of the CIT group، seven isolates carried genes belonging to the MOX group، three and one isolates carried genes belonging to the EBC and DHA groups، respectively. ACC and FOX groups were not found in our isolates. This study is the first report of MOX group of AmpC β-lactamases in K. pneumoniae in Iran. High prevalence of plasmid-mediated AmpC in the central hospital of Arak، indicating the antibiotic resistant، is a major concern; hence، antibiotic prescription policy should be revised and infection control measure is necessary to be improved.

Vibrio cholera is an important agent causing cholera in human. The expression of Flagellum and the movement of the bacterium are critical in the colonization and virulence of Vibrio cholera. FlaA gene is one the five genes encoding Flagellin which plays an important role in the activity and movement of the bacterium and its colonization which has a significant role in its immunogenicity. The aim of this study was to express and produce the recombinant FlaA protein in E.coli using Western blot method.

In this experimental study, FlaA gene was proliferated by PCR method using the specific primers and cloned with BamHI and Xhol in pTz57R/T. Then it was proliferated and sequenced in DH5a vector of E.coli. The cloned FlaA gene was inserted into pGEX-4T-1 vector. The cloned vector was transformed to BL21-DE3 of E. coli and successfully expressed by induction of IPTG. The expressed protein was purified by GST affinity resin. For preparation of the primary antibody, the purified recombinant protein was injected to rats. Western blot assay method was used for determining the antigenicity of the recombinant FlaA.

Determination of gene sequencing showed that this gene has been proliferated properly and the antibody used in Western blot verified the production of the recombinant protein.

The results of this study demonstrate that FlaA protein is immunogenic and can be evaluated in vaccine designing and as a diagnostic tool for detection of cholera infection.