Iranian Journal of Veterinary Science and Technology
Volume:12 Issue: 1, Winter and Spring 2020

Staphylococcal infections and contaminations have elicited a growing and perennial concern in the medical and food industries. Meanwhile, the manifestation of antibiotic-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA) beside the production of disinfectant-resistant biofilms makes the confrontation with the bacteria more cumbersome and challenging. Pomegranate peel as a waste product of juicing factories is a natural antibacterial agent. The pomegranate peel hydro-extract (PPHE), as a bio-friendly material, was prepared from an Iranian pomegranate cultivar, Rabab, and its phenolic compounds and antioxidant (via DPPH and FRAP assays) and anti-staphylococcal (anti-planktonic and anti-biofilm) properties were assessed. The Rabab PPHE inhibited planktonic cells and biofilm formation of three S. aureus. The Rabab PPHE produced large and obvious staphylococcal inhibition zones in which their diameters were significantly dose-dependent for the milk isolated S. aureus (p < 0.05). Despite the resistance of MRSA (ATCC 33591) to beta-lactam antibiotics, the minimum inhibitory concentration (MIC) of PPHE against its planktonic cells was only 3.75mg mL-1. Furthermore, Rabab PPHE inhibited bacterial biofilms formation in a dose-dependent manner. The MIC of Rabab PPHE against planktonic milk-isolated S. aureus, S. aureus (ATCC 29737), and MRSA prevented 47, 36, and 26% of their biofilm formation, respectively. This addresses the differences between the anti-planktonic and anti-biofilm activity of Rabab PPHE. The anti-planktonic and to a lesser extent the anti-biofilm forming activity of this water-based extract supports the notion of its effectiveness and salubrious application in food and pharmaceutical industries.

This study aimed to isolate bacteriophages specific to Shiga toxin-producing Escherichia coli (E. coli) strains, particularly EHEC O157:H7, in order to develop a collection of phages against different E. coli pathotypes isolated from northeast of Iran. Eighteen samples were screened without any preliminary enrichment and also with small scale enrichment using E. coli 12900, which did not result in the phage recovery. Seven samples were prepared with an extensive enrichment. Of them, 5 samples produced plaques. Eventually, seven phages out of thirteen isolated phages were selected for phage host range investigation. Results of the spotting host range assay demonstrated that 22 pathogenic E. coli strains and isolates (54%) were susceptible to at least one of the phages. Phage Ecol-MHD1 was polyvalent against E. coli and Salmonella isolates. The other phages were specific to E. coli pathotypes. In conclusion, the phages isolated in this study can be suggested as preventive or therapeutic candidates against foodborne E. coli infections in humans.

This research was performed on uropathogenic Escherichia coli (E. coli) isolates and established the genes of resistance to ciprofloxacin between the isolates. A total of one hundred and three urine samples were tested for uropathogenic E. coli which were obtained from dogs with urinary tract infections (UTIs) using cultural isolation, antimicrobial susceptibility test, and polymerase chain reaction (PCR). The results revealed that genes associated with ciprofloxacin resistance are 24.3% positive for E. coli. The E. coli isolates were resistant to both ciprofloxacin and ampicillin (100%), highly susceptible to chloramphenicol (84.0%), and less susceptible to gentamycin (44.0%) and amikacin (40.0%). The PCR tests showed the presence of the ParC (in 25 samples; 100%), GyrA (in 25 samples; 100%), and GyrB (in 4 samples; 16.0%) genes. The findings of the present study showed an upsetting rate of ciprofloxacin and ampicillin resistance among the E. coli isolates from dogs with UTIs.

Many diseases, including renal disorders in ruminants, appear in subclinical form and lead to reduced production without causing clinical signs. In this research, blood and tissue samples of kidney were taken from 102 buffaloes from Ahvaz industrial abattoir and sent to the laboratory for biochemical and histopathological analysis. After preparing the pathological sections from kidney specimens, conventional and specific staining and microscopic examination, 41 samples had no kidney lesion was considered as control and 61 specimens as the lesion group. The samples with renal lesions were divided into 4 subgroups including acute tubulointerstitial nephritis, chronic tubulointerstitial nephritis, Urinary tubular inflammation, and Congestion. The samples were also divided and compared to males and females. In blood samples, serum biochemical tests including parathyroid hormone, erythropoietin, and vitamin D3 were measured by using ELISA-specific commercial kits. After statistical analysis, the results of vitamin D3 in the studied groups did not show any significant difference. However, erythropoietin and parathormone values in buffaloes with renal lesions were significantly lower and higher than those in control animals respectively. The results of this study showed that most of the kidney lesions in the studied buffaloes including the mentioned above have led to a decrease in the production of erythropoietin hormone following the occurrence of these lesions and its functional effects on the kidneys. Naturally, the effects of this hormone deficiency are expected to be reflected in the hemogram and eventually, anemia resulting from it may affect overall body health.

The present study examined the effects of overripe banana (Musa cavendish) pulp and green banana peel extract and powder on oxidants/antioxidants parameters and some minerals in Holstein dairy calves. Forty newborn calves were randomly divided into four groups of 10 (control, group one, group two and group three). The groups were homogenous for the parity of the dams and the time of birth. Within 12-48 hours of birth, calves were assigned to their treatment groups. In the control group, animals received no banana meal. In group one, calves were supplemented with 2 g (dry matter)/kg body weight/day of overripe banana pulp extract for five days. The calves in group two were supplemented with 1 g (dry matter) of overripe banana pulp extract /kg body weight/day and 1 g (dry matter) of green banana peel extract/kg body weight/day for five days. The animals in group three were supplemented with 2 g/kg body weight/day of green banana peel powder for five days. Blood samples were taken on day 0 (at birth) and on days 7, 15 and 30 through the jugular vein. Age (the time of sampling) had a significant effect on the values of phosphorous, potassium, iron, copper, FRAP and activity of GPx enzyme (p < 0.05). Significant group and sampling time interaction was seen for the FRAP concentrations (p < 0.05). In conclusion, banana supplementation in the Holstein dairy calf ’s diet at the concentration and duration that was reported in the present study had beneficial effect on the values of FRAP.

The type of device used, the type of local anesthetic agents, and the animal species may affect the intraocular pressure (IOP). Therefore, in order to determine these issues, the effects of four local anesthetics were investigated in 10 adult rabbits by ICare TA01i and Tono-Pen Vet tonometers. In the right eye of half of the rabbits and in the left eye of the other half of the rabbits, one drop of tetracaine was instilled. The IOP in each rabbit was measured using two tonometers, ICare and Tono-Pen Vet, before and each 5 minutes until 40 minutes later. The effects of other drugs were also studied at least with one-week interval. Based on the results of ICare tonometer, tetracaine significantly reduced the IOP immediately and 25 minutes after instillation. IOP changes after instillation of bupivacaine, lidocaine and proparacaine were not significant at any time compared to baseline values (p > 0.05). Based on the results of Tono-Pen Vet tonometer, all drugs reduced the IOP immediately after use; however, the effects of bupivacaine and lidocaine on IOP were much lower than that of tetracaine and proparacaine. The average duration of corneal anesthesia were 20, 15.5, 7.5 and 21 minutes for tetracaine, bupivacaine, lidocaine, and proparacaine, respectively. It is concluded that IOP reduction by local anesthetics when Tono-Pen Vet is used is much greater than the ICare tonometer measurements. Also, the reduction of IOP with each of the devices when tetracaine or proparacaine is used is greater than when bupivacaine or lidocaine is used.

The present study was designed to investigate the effect of different available bedding materials on learning and memory performance, bedding texture preference as well as intra-cage ammonia concentration in rats. The animals were housed on different bedding types for two weeks. Bedding materials were produced in the same sizes from poplar, walnut, pistachio, apricot, almond woods and alfalfa steam and live. Spatial and passive avoidance learning and memory were assessed by Morris water maze (MWM) and shuttle box tasks. A modifying six-arm radial maze was used to assess bedding texture preference by rats. For each bedding groups, average ammonia level (ppm) over a week was calculated. The data indicated that the rats that had walnut and almond chips show better learning and memory performance in both MWM and shuttle box tests than other groups. The weakest learning and memory performances were observed in rats exposed to alfalfa bedding. In texture preference test, the rats spent more time in walnut and almond arms, and less time in alfalfa. Besides, the total water and food intake as well as the number of visit to alfalfa arm were decreased as compared to other arms. Moreover, in alfalfa bedding cage, average intra-cage ammonia level was utmost. Overall, current bedding materials may contain diverse biochemically effective compounds or individual micro edges which alter learning and memory performances of rats.

Pseudomonas infections are an important cause of morbidity and mortality and saprophytic fungi are now increasingly being recognized as serious pathogens in immunocompromised patients. To investigate the effect of using bio-materials on mammalian tissues, two experiments were designed; the first one was feeding of Balb/c mice with irrigated lettuce with bio-fungicide (mutant and wild) and bio-fertilizers prepared with Pseudomonas (p) fluorescens, p. putida, p. aeruginosa, and the second was the usage of drinking water containing (Trichoderma (T) spores (mutant and wild) or P. fluorescens, P. putida, P. aeruginosa suspensions). Then, blood factors and inflammation of tissues (liver, kidney, spleen and large intestine) in all mice were analyzed after two months. Blood samples were taken from the mice to examine some of the hematological (RBC, MCV, MCH, MCHC) (data not shown) and biochemical (AST, ALT, ALP) factors, and also observed under a microscope. The study of tumor marker carcinoembryonic antigen (CEA) in all treatments showed that the strains in these bio-fertilizers did not stimulate carcinogenic indices. The results from the other blood factors were normal for all strains (data not shown). Only P. putida showed no adverse effect on the increase in alkaline phosphatase (ALP). The results also showed that the effect of bio-fungicide on mammalian tissues (spleen and large intestine) was normal. But a small number of mild liver necrosis was seen in the treatment groups with wild Trichoderma, and moderate necrosis in the the liver tissue after treatment with mutant Trichoderma isolates. More investigation should be made to determine the impact of these biotic factors on the mammalian tissues before commercialization.

Quorum sensing (QS) is a cell density dependent mechanism used by many pathogenic bacteria for regulating virulence gene expression. Inhibition or interruption of QS by herbal remedies has been suggested as a new strategy for fighting against antibiotic resistant bacteria. The aim of this study was to evaluate the antibacterial activity of Satureja sahendica hydroalcoholic extract (SSHE) against Salmonella Typhimurium (S. Typhimurium) isolates, and to assess the impact of sub-inhibitory concentrations of this extract on the QS-associated gene (sdiA) expression. Using the Soxhlet method, hydroalcoholic extract of S. sahendica leaves was prepared and antimicrobial effects of the SSHE were determined by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methodS. The reverse transcription quantitative PCR (RT-qPCR) assay was used to analyze the expression of sdiA in 20 S. Typhimurium isolates from poultry flocks in response to the treatment of sub-inhibitory concentrations of SSHE at 60-min time point. The MIC values of SSHE against S. Typhimurium isolates were ranged from 0.29-4.68 mg/ml-1 and MBC values were ranging from 75-150 mg/ml-1. The results also indicated that the expression of sdiA gene was reduced in S. Typhimurium isolates triggered by the treatment of SSHE comparatively with those from the control cultureS. Findings suggest that SSHE possess the antibacterial and anti-QS activity and can be used to control the expression of virulence genes in pathogenic bacteria, such as S. Typhimurium.