Iranian Journal of Veterinary Science and Technology
Volume:14 Issue: 1, Winter 2022

Frequent and unlimited use of antibiotics caused the development of antibiotic resistance by microorganisms. Therefore, there is an argent need to discover novel antibacterial agents or a combination of agents as a safe treatment strategy for various infections. In the present study the synergistic effects of cLFchimera, an antimicrobial peptides, and Vancomycin antibiotic were evaluated using checkerboard method against Methicillin Resistant Staphylococcus aureus (MRSA) bacteria strain. cLFchimera had antimicrobial activity against MRSA and Methicillin Sensitive Staphylococcus aureus (MSSA) (MIC: 256 and 512 µg/mL, respectively). A synergistic effect was observed in the combination of cLFchimera with Vancomycin (FIC: 0.375). The results showed that at FIC concentrations, release cytoplasmic materials from bacterial cells and the number of surviving cells were significantly (P≤0.05) higher and lower, respectively, than when peptides or antibiotic were used alone. SEM electron microscopic analysis at FIC concentration showed severe membrane damage of bacterial cells. In conclusion, the use of cLFchimera and Vancomycin at FIC concentration reduces the consumption of both substances.

Serotonin (5-HT) plays an underpinning role in appetite regulation and the opioid system has a role in the modulation of the ingestion behavior in birds. The current survey was aimed to evaluate the effect of opioid receptors on serotonin-induced hypophagia in neonatal broilers. During experiments, food-deprived chickens received intracerebroventricular (ICV) injection and thereafter, the cumulative food intake was measured after 30, 60, and 120 minutes. In experiment 1, to determine the effective dose of serotonin, the control solution and the various doses of serotonin (2.5, 5, and 10 μg) were administered to birds. In the second experiment, groups received not only the control solution, but also an effective dose of serotonin (10 µg), µ-opioid receptor antagonist (β_FNA, 5 µg), and a co-injection of β_FNA (5 µg) and serotonin (10 µg), respectively. The next experiments were similar to the second experiment, however, in place of β_FNA, the antagonist of κ- opioid receptor (nor_BNI, 5 µg), the δ- opioid receptor antagonist (NTI, 5 µg), and the agonist of µ opioid receptor (DAMGO, 62.25 pmol) were used in experiments 3, 4, and 5, respectively. The results showed a dose-dependent hypophagic impact of serotonin. This effect was attenuated by β_FNA; however, nor_BNI and NTI had no effect. Furthermore, the diminishing effect of serotonin on food consumption in chickens was strengthened following DAMGO administration (p < 0.05). According to the results, the hypophagic effect of serotonin is possibly mediated through µ opioid receptors in neonatal broilers.

The present study was performed to assess the resistance profile to fluoroquinolone and to determine mutations in gyrA and parC genes of Escherichia coli in bovine coliform mastitis. Fluoroquinolones (norfloxacin (NOR), ciprofloxacin (CIP), enrofloxacin (NFX), levofloxacin (LEV), and ofloxacin (OFL) were tested against E. coli isolates, isolated from bovine mastitis (100 milk samples) by disk diffusion method. To determine the extent of gyrA and parC mutations associated with fluoroquinolone resistance in E. coli, two isolates with the highest resistance to each fluoroquinolone were submitted for the amplification and sequencing of the quinolone resistance-determining regions (QRDRs) of gyrA and parC genes. The disk diffusion method indicated that E. coli isolates had the highest intermediate resistance to OFL (16.7%), followed by NFX and NOR (15%), while they had low resistance to CIP and LEV (3.33%). A few silent mutations in gyrA (in codons 91, 100, 111, 131, 132) and in parC (in codons 91, 157, 159) were detected in QRDRs, and mutations in nucleotides 65, 80, and 83 in gyrA, and 195, 209, 212 in parC were detected in the other isolate. These results showed an intermediate rate of resistance to fluoroquinolones in E. coli isolates from raw milk of cows with coliform mastitis

Fish farming is increasing globally, with an increase in bacterial infections known to cause morbidity and varying mortality, affecting the productivity and profitability of aquaculture. The objective of this study was to determine the antibiotics susceptibility and multiple antibiotic resistance index of bacteria isolated from fish in some selected fish farms in Kaduna State to ten commonly used antibiotics using the Kirby-Bauer disc diffusion method. In total, 84 bacteria were isolated from 75 Clarias gariepinus in this study, belonging to 12 genera. The antibiotic profile of the bacteria isolated displayed different sensitivity and resistance to the antibiotics used. The highest numbers of the Gram-positive (59.5%) and Gram-negative (69%) bacteria, respectively, were sensitive to ciprofloxacin compared to the other antibiotics. All the bacterial isolates displayed varying diversity of multidrug-resistant patterns. A total of 38 and 41 different resistance patterns for Gram-positive and Gram-negative respectively were observed. The multiple antibiotic resistance (MAR) index analysis reveals that 97.3% of the bacteria had a high MAR index value (> 0.2). In conclusion, there is a diversity of bacteria organisms within the fish farms that are pathogenic to both fish and humans. Therefore, there is a need to implement optimal preventive management measures and control the use of antibiotics.

The present study aimed to evaluate the effect of short-time progesterone injection subcutaneously (SC) on estrus synchronization of Baluchi ewes. All ewes received one dose of PGF2α (15 mg) and then were divided into two groups. In the P4 group, a combination of progesterone and propylene glycol was subcutaneously injected twice at the three-day interval, and a vaginal sponge was used in the control group for 6 days.  On day 6, all ewes received 400 IU of eCG. 48h after eCG injection, two rams were introduced into the flock. Blood samples were taken daily from Day 0 to Day 13 to measure serum progesterone concentration. Ultrasonography was used to observe ovaries and monitor their changes at three-day intervals. In P4 and control groups, the estrus rate was 88.9% and 100% for P4 and control groups, respectively; the duration of estrus for the P4 and control groups was 8 and 8.5 days, respectively (p >0.05). No significant difference was observed in the size of the largest follicle and the number of follicles more than 2 mm in diameter between the treatment and control groups. Further studies with some changes and modifications are required for gaining acceptable fertility and prolificacy rates.

The developmental error of the first pair of pharyngeal arch processes would result in a group of malformations related to the oral cavity. These malformations can be listed as agnathia, micrognathia, brachygnathia, syngnathia, cleft palate, campylognathia, parrot beak, and strophocephalia. Campylognathia is an anomaly in which the lower or upper jaw deviated from the midline. Clinical examination of a newborn female Holstein Friesian calf showed mandibular deviation, inferior and superior cheek teeth deformation, and some other facial malformations. No similar case was detected in the history of the herd. Precise consideration of malformed animals and the extent of involvement of different structures indicates the pattern of malformation, the time of teratogenic effect, and the motive embryonic structures. In the present case, the involvement of derivatives of both maxillary and mandibular processes shows the responsibility of the first pharyngeal arch for mentioned abnormalities. In humans, different types of abnormal development of the first pharyngeal arch have been reported and so, have been classified under the “first visceral arch syndrome”. But according to the infrequency of reports, this classification has not been done in domestic animals.

In ruminant, the kidneys are a major excretory organ that eliminate metabolic byproducts and regulate water-electrolyte homeostasis and maintain acid-base balance in the body. Therefore, kidney abnormalities cause a life-threatening effect on ruminants’ health. Renal torsion has not been reported in any animal species. In the present report, a case of a two-month-old male lamb that has unilateral renal torsion has been described. In necropsy, the twisted left kidney was severely congested and was enlarged in size. Histopathological studies revealed renal tubular and glomeruli necrosis. Vascular changes consisted of congestion and thrombi in the blood vessels. Abnormalities in the embryonic developmental period and increased mobility of the renal structure due to ligaments associated with a twisted kidney are suspected causes of the occurrence of renal torsion.