Aeromonas is recognized as a human pathogen following ingestion of contaminated food and water. One major problem in Aeromonas identification is that certain species are phenotypically very similar. The antimicrobial resistance is another significant challenge worldwide. We therefore aimed to use mass spectrometry technology for identification and discrimination of Aeromonas species and to screen the antimicrobial resistance of Aeromonas hydrophila (A. hydrophila). A total of 150 chicken meat and water samples were cultured, and then, the isolates were identified biochemically by the Vitek® 2 Compact system. Proteomic identification was performed by MALDI‐TOF MS and confirmed by a microchannel fluidics electrophoresis assay. Principal component analysis (PCA) and single‐peak analysis created by MALDI were also used to discriminate the Aeromonas species. The antimicrobial resistance of the A. hydrophila isolates was determined by Vitek® 2 AST cards. In total, 43 samples were positive for Aeromonas and comprised 22 A. hydrophila, 12 Aeromonas caviae (A. caviae), and 9 Aeromonas sobria (A. sobria) isolates. Thirty‐nine out of 43 (90.69%) Aeromonas isolates were identified by the Vitek® 2 Compact system, whereas 100% of the Aeromonas isolates were correctly identified by MALDI‐TOF MS with a score value ≥2.00. PCA successfully separated A. hydrophila, A. caviae and A. sobria isolates into two groups. Single‐peak analysis revealed four discriminating peaks that separated A. hydrophila from A. caviae and A. sobria isolates. The resistance of A. hydrophila to antibiotics was 95.46% for ampicillin, 50% for cefotaxime, 45.45% for norfloxacin and pefloxacin, 36.36% for ceftazidime and ciprofloxacin, 31.81% for ofloxacin and 27.27% for nalidixic acid and tobramycin. In conclusion, chicken meat and water were tainted with Aeromonas spp., with a high occurrence of A. hydrophila. MALDI‐TOF MS is a powerful technique for characterizing aeromonads at the genus and species levels. Future studies should investigate the resistance of A. hydrophila to various antimicrobial agents.

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Psychrotrophic Pseudomonas is one of the significant microbes that lead to putrefaction in chilled meat. One of the biggest problems in the detection of Pseudomonas is that several species are seemingly identical. Currently, antibiotic resistance is one of the most significant challenges facing the world's health and food security. Therefore, this study was designed to apply an accurate technique for eliminating the identification discrepancy of Pseudomonas species and to study their resistance against various antimicrobials. A total of 320 chicken meat specimens were cultivated, and the isolated bacteria’ were phenotypically recognized. Protein analysis was carried out for cultured isolates via Microflex LT. The resistance of Pseudomonas isolates was recorded through Vitek® 2 AST-GN83 cards. Overall, 69 samples were identified as Pseudomonas spp. and included 18 Pseudomonas lundensis (P. lundensis), 16 Pseudomonas fragi (P. fragi), 13 Pseudomonas oryzihabitans (P. oryzihabitans), 10 Pseudomonas stutzeri (P. stutzeri), 5 Pseudomonas fluorescens (P. fluorescens), 4 Pseudomonas putida (P. putida), and 3 Pseudomonas aeruginosa (P. aeruginosa) isolates. Microflex LT identified all Pseudomonas isolates (100%) correctly with a score value ≥ 2.00. PCA positively discriminated the identified isolates into various groups. The antimicrobial resistance levels against Pseudomonas isolates were 81.16% for nitrofurantoin, 71% for ampicillin and ampicillin/sulbactam, 65.22% for cefuroxime and ceftriaxone, 55% for aztreonam, and 49.28% for ciprofloxacin. The susceptibilities were 100% for cefotaxime, 98.55% for ceftazidime, 94.20% for each piperacillin/tazobactam and cefepime, 91.3% for cefazolin. In conclusion, chicken meat was found to be contaminated with different Pseudomonas spp., with high incidence rates of P. lundensis. Microflex LT is a potent tool for distinguishing Pseudomonads at the species level.

Beef and dairy cows differ in the way in which they utilise nutrients and in accretion or mobilisation of body reserves during lactation. Thus far, little is known about the impact of lactation performance on body composition, meat quality, and the related muscle structure of cows with a defined, combined beef and dairy genetic background. In the described experiment, 50 F 2 cows, originating from mating Charolais bulls to German Holstein cows and a following intercross of F 1 individuals, were slaughtered during the second lactation, 30 days after calving. Cows were assigned to 3 groups, each containing representatives of 3 families, according to lactation performance. Standard carcass and meat quality traits were determined. Additionally, samples from longissimus muscle were investigated by histology and computer image analysis for muscle fibre profile, intramuscular fat cell size, and marbling traits. Subcutaneous fat cell size was measured to estimate the impact of lactation on body fat reserves. The results suggest no influence of the duration of the first lactation on body composition, meat quality or muscle structure. However, the amount of milk per day influenced body weight, body composition, and marbling traits. Relationships between traits were low, but showed consistently that increasing milk yield was negatively correlated with tissue accretion. Changes of muscle fibre and fat cell profile, indicating protein or fat mobilisation by lactation, could not be detected. In the presented study, lactation had only minor consequences for meat quality.

Although () is a highly significant pathogen, its source remains unclear. Many people consume chicken daily as a source of animal protein worldwide; thus, hygienic methods of supplying chickens for consumption are critical for public health. Therefore, our study examined the distribution of the (), , and virulence genes in strains in chicken meat and giblets (gizzards and livers) and the resistance of the strains to various antibiotics. Ninety chicken meat, gizzard and liver samples were obtained from a semi-automatic abattoir in Sadat City, Egypt, and were cultured and preliminarily analyzed using biochemical tests. The presence of the ,, and genotypes was tested for in samples positive for by multiplex polymerase chain reaction (Multiplex-PCR). The resistance of to various antimicrobial drugs was tested using the disc diffusion method. In total, 7 of the 90 chicken samples were positive for (7.78%); in 3/7 (42.85%) samples, the bacteria were found in the chicken liver, while the bacteria were found in the meat in 2/7 (28.57%) and in the gizzard in 2/7 (28.57%) samples. The total prevalence of both the and genes in the isolated strains was 100%, while the prevalence of the and genes was 57.1% and 42.9%, respectively. The resistance of to the antibiotics utilized in our study was 100% for streptomycin; 85.7% for amoxicillin and penicillin; 71.4% for oxytetracycline, nalidixic acid and ampicillin; 57.1% for sulfamethoxazole and erythromycin; and 42.9% for neomycin, chloramphenicol and norfloxacin. In conclusion, the chicken meat and giblets were tainted by, with a higher occurrence of the ,, and genotypes. Future investigations should investigate the resistance of to various antimicrobial agents in Egypt.

We have isolated phage clones from Drosophila melanogaster genomic and cDNA libraries containing a sequence homologous to the murine Int-i protooncogene. The Drosophila gene is represented by a single locus at position 28A1-2 on chromosome 2. The gene is expressed as a 2.9-kilobase-long polyadenylylated mRNA in embryo, larval, and pupal stages. It is hardly detectable in adult flies. The longest open reading frame of the cDNA clone corresponds to a protein 469 amino acids long. Alignment of the predicted amino acid sequences shows that the Drosophila protein is 86 amino acids longer than its murine counterpart. In spite of the difference in length, the two proteins are highly conserved with an overall sequence homology of 54%. Both Drosophila and murine Int-i proteins begin with a hydrophobic leader sequence and contain cysteine residues and sites for glycosylation (four in the murine protein and one in the Drosophila protein) in conserved positions, suggesting that they play important functional roles. Cellular protooncogenes have been highly conserved by evolution, suggesting that they may serve important household functions (1). Although their precise function is not known or is only incompletely known, it is already clear that they fall into several groups, such as growth factor or growth factor receptor genes, signal transducers, and DNA-binding nuclear proteins (1). They are believed to participate in the regulation of cell division, although at different levels. Some oncogenes have been shown to hybridize with highly homologous sequences in such genetically well-known organisms as yeast or Drosophila. This is of great interest because the knowledge and the possibility of genetic manipulations provide unparalleled possibilities to obtain important functional clues. The pioneering studies of Shilo have identified 4 oncogene homologs in Drosophila DNA (2). The total number has now increased to 11 and includes three major families, the tyrosine kinases, the ras-group, and the nuclear oncogenes (3). In a search for previously unidentified oncogene homologs, we have screened Drosophila genomic libraries with cDNA probes of mammalian c-myc, N-myc, c-fos and c-int-i. We report the isolation and preliminary characterization of a Drosophila int-i homolog. § The cellular homolog of the viral v-int-i has been discovered and implicated in mouse mammary tumorigenesis on the basis of its frequent insertional activation in murine mammary tumor virus (MMTV)-associated tumors (4); the murine homolog is called lnt-i. It is expressed in the fetal central nervous system (5, 6) and during the late stages of spermatogenesis (6) but not in most normal adult tissues. The murine Int-1 protein contains 370 amino acids and is rich in cysteine residues (7). The active product of the gene and its biochemical features in normal and malignant cells are not known. MATERIALS AND METHODSMolecular Cloning. A recombinant Drosophila genomic library cloned into Charon 4A (8) was screened with a 32P-labeled murine Int-1 cDNA probe (9) b...

Key words:Oreochromis niloticus, Mercury, lead, cadmium, Nile River Subjection to Heavy metals is an imperative normal issue coming to fruition because of various human exercises. The aim of this study was the assessment of some heavy metals and its possible hazards on fish and consumers. Eighty Nile tilapia fillet samples were collected from Nile canals and markets in Menoufia, Egypt for analysis of Mercury (Hg), lead (Pb), and cadmium (Cd), using atomic absorption flame. In general, wild tilapia samples contained higher mercury, lead and cadmium than those of farm tilapia samples. A positive correlation between heavy metals concentration and the fish size was observed, as the large sized tilapia samples had higher heavy metal residues than those of the small sized tilapia samples. Heavy metal levels in some fish samples in our investigations exceeded the maximum permissible limits of Egyptian standards.

Leptin may act as the critical link between adipose tissue and reproduction. Although considerable progress has been achieved in understanding the reproductive actions of leptin, much work is needed for understanding its physiological role. Till now, no data has been published about the distribution and expression levels of leptin in the rabbit maternal adipose tissue, placenta, and various fetal rabbit tissues during pregnancy and postpartum. Our results indicated that circulating leptin levels in rabbit serum during pregnancy were significantly higher than in postpartum and non pregnant rabbits. Furthermore, leptin showed positive correlations with body weight and estrogen and negative correlation with progesterone in pregnant and postpartum rabbits. RT-PCR verified the presence of RNAs encoding leptin in the rabbit maternal perirenal adipose tissue, placenta, and several fetal tissues; including brain, liver, adipose tissue, and bone. The relative abundance of leptin RNA in rabbit maternal adipose was significantly higher at 20 th day of pregnancy than that of non pregnant rabbits, while it was significantly decreased at 2 nd day after parturition. No significant changes in the placental leptin RNA levels were noticed in pregnant rabbits at 10 th , 20 th , and 30 th day of pregnancy. The relative abundance of fetal leptin transcripts at day 30 th of pregnancy was in the order of liver> bone ≥ adipose tissue > brain. The present study provides new evidence for the distribution and expression levels of leptin in the rabbit maternal and fetal tissues during pregnancy and supports the importance of leptin in reproductive physiology and fetal development.