Occurrence of Escherichia coli carrying Shiga toxin-producing genes in buffaloes on smallholdings in Bangladesh

Research (Published online: 19-10-2018)

15. Occurrence of Escherichia coli carrying Shiga toxin-producing genes in buffaloes on smallholdings in Bangladesh

Mukta Das Gupta, Arup Sen and Ashutosh Das

Veterinary World, 11(10): 1454-1458

ABSTRACT

Background and Aim: Shiga toxin-producing Escherichia coli (STEC) has emerged as significant foodborne pathogens. Ruminants are the primary reservoir of the zoonotic STEC. In Bangladesh, previous studies reported the presence of STEC in cattle, goat, and sheep; however, there is little information about STEC carriage by buffaloes. This study aimed to determine the occurrence of STEC in healthy (absence of clinical signs and symptoms) buffaloes on smallholdings in Bangladesh and to assess the antimicrobial resistance pattern of identified STEC isolates.

Materials and Methods: A total of 100 rectal swab samples were obtained from randomly selected buffaloes on 40 smallholdings in Chittagong Division, Bangladesh. Samples were subjected to bacteriological screening to identify E. coli. All E. coli isolates were examined for the presence of the Shiga toxin-producing genes - Shiga toxin 1 (stx1) and Shiga toxin 2 (stx2) using polymerase chain reaction. The antimicrobial susceptibility of identified STEC isolates was tested using the disk diffusion method.

Results: Results show that 71 fecal samples were positive for E. coli in bacteriological screening. The proportion of buffaloes harboring STEC isolates was 11% (11/100) (95% confidence interval [CI] 6.1-18.8], of which 7% (7/100) (95% CI 3.2- 13.9) and 4% (4/100) (95% CI 1.2-10.2) carried stx1 and stx2 genes, respectively. Antibiogram revealed that 91% (10/11), 73% (8/11), 55% (6/11), and 55% (6/11) STEC isolates were resistant to tetracycline, sulfamethoxazole-trimethoprim, erythromycin, and ampicillin, respectively. In contrast, 91% (10/11) STEC isolates were sensitive to ciprofloxacin, chloramphenicol, and gentamicin, whereas 73% (8/11) isolates were sensitive to ceftriaxone.

Conclusion: This study highlights, for the first time, a significant proportion of fecal samples from healthy buffaloes on smallholdings in Bangladesh harboring antimicrobial-resistant STEC. Transmission of antimicrobial-resistant STEC from buffaloes to humans could pose an added risk to public health in rural Bangladesh.

Keywords: antimicrobial resistance, buffalo, Shiga toxin-producing Escherichia coli.

Antibacterial effect of ozonated water against methicillin-resistant Staphylococcus aureuscontaminating chicken meat in Wasit Province, Iraq

Research (Published online: 18-10-2018)

14. Antibacterial effect of ozonated water against methicillin-resistant Staphylococcus aureuscontaminating chicken meat in Wasit Province, Iraq

Manal H. G. Kanaan

Veterinary World, 11(10): 1445-1453

ABSTRACT

Background and Aim: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most recognized "superbugs" and a common cause of community-associated and nosocomial infections; furthermore, when chicken meat is considered a good growth medium for S. aureus to make a plausible vehicle to propagate MRSA, then this study was conducted to evaluate the efficiency of ozonated water (0.5 ppm) in the elimination or reduction of MRSA contaminating fresh and frozen chicken meat sold in local markets in the Wasit Province.

Materials and Methods: A total of 72 samples of fresh and frozen chicken meat were randomly collected from dissimilar native markets: Fresh chicken meat (n=32) and frozen chicken meat (n=40). Isolation and identification of MRSA isolates were conducted using standard bacteriological, biochemical, RapID™ Staph Plus System (Remel, R8311009), and latex agglutination tests such as Dry SPOT Staphytect Plus (Oxoid, DR0100M) and PBP2' Test Kit (Oxoid, DR0900A). The generation of ozone (O3) was carried out using O3 generator (A2Z/AQUA-6, USA), and its concentration (ppm) in water was determined using CHE-Mets®-Kit, USA.

Results: A total of 39 (54.2%) of 72 fresh and frozen chicken meat were positive for S. aureus; of those 39 positive samples, 13 (33.3%) were identified as MRSA. The antibiotic sensitivity test results revealed that all MRSA isolates had multiple resistance to at least four antimicrobial agents for which these isolates had 12 antibiotic resistance patterns. Results of O3 treatment in MRSA isolate contaminating 13 of both fresh and frozen chicken meat samples showed that, after treatment with ozonated water (0.5 ppm/4°C), the overall negative samples were 23.1% and 69.2% for 30 and 45 min, respectively. The decrease in the percentage of positive samples was very significant from a public health perspective. Furthermore, the antimicrobial efficacy of ozonated water (0.5 ppm) on the reduction of the MRSA count (log10 colony-forming units [CFU]/ml) was assessed in four positive samples of fresh and frozen chicken meat, and the results revealed that, after treatments, the overall reduction was 2-4 log10 (CFU/ml) after 45 min. This reduction is highly significant from a public health perspective.

Conclusion: From the data obtained from this study, it can be concluded that fresh and frozen chicken meat sold in the different markets of Wasit Province was highly contaminated by S. aureus during the study period with a total prevalence of 54.2%; among those, 33.3% were recognized as MRSA. Under the conditions described in the present study, O3 at the concentration of 0.5 ppm is highly effective in reducing the number of MRSA-positive samples and the number decreased with increased exposure time to ozonated water at the same concentration. These findings indicated that O3 treatment might constitute the basis for an alternative method to reduce meat contamination with foodborne pathogens such as MRSA.

Keywords: antibacterial effect, chicken meat, methicillin-resistant Staphylococcus aureus, ozonated water, Wasit Province.

Antagonistic effect of ursolic acid on Staphylococcal biofilms

Research (Published online: 17-10-2018)

13. Antagonistic effect of ursolic acid on Staphylococcal biofilms

J. Shiva Jyothi, Kalyani Putty, Y. Narasimha Reddy, K. Dhanalakshmi and M. A. Hannan Umair

Veterinary World, 11(10): 1440-1444

ABSTRACT

Aim: The present study was carried out to study the effect of ursolic acid (UA) as a potential anti-biofilm agent in dispersing the biofilm generated by Staphylococcus aureus isolated from milk samples of crossbred dairy cows on the day of drying. Further, in the S. aureus isolates, the presence of intracellular adherence gene locus involved in biofilm production (icaD) was investigated.

Materials and Methods: A total of 50 S. aureus strains were isolated over a period of 3 months from 200 milk samples collected from crossbred dairy cows on the day of drying. These isolates were subjected for biofilm detection by Congo red agar (CRA), microtiter plate assay (MTP), and polymerase chain reaction specific for icaD gene. The antagonistic effect of biofilm formation by UA was studied using different concentrations (30 μg/ml and 60 μg/ml) of UA and compared with the control group.

Results: Among the 50 S. aureus subjected for biofilm detection, 34 and 40 isolates were detected as biofilm agents by CRA and MTP methods, respectively. The in vitro studies on the effect of UA in inhibiting biofilm formation by S. aureus using MTP assay showed 71.5% and 48.6% inhibition at UA concentrations of 60 μg/ml and 30 μg/ml, respectively, with a significant difference (p<0.05) between the treated and untreated isolates, which was further evident by scanning electron microscopy. Interestingly, the isolates that were tested to be resistant through Antibiotic Sensitivity Test to commonly used antibiotics were found to be sensitive to all the tested antibiotics following UA treatment at both the tested concentrations. Furthermore, molecular detection of icaD gene for biofilm detection revealed that all the isolates that were positive by MTP had icaD gene.

Conclusion: Increased incidence of biofilm agents in dairy infections must be considered as an alarming situation. UA treatment significantly enhanced the sensitivity of the microbial pathogens to commonly used antibiotics. Hence, attention must be paid toward implementation of new strategies such as therapeutic regimes with a combination of antibiotic and anti-biofilm agents for effective treatment of infections in dairy farms.

Keywords: biofilms, icaD, Staphylococcus aureus, ursolic acid.

Supplementation of whole grain flaxseeds (Linum usitatissimum) along with high cholesterol diet and its effect on hyperlipidemia and initiated atherosclerosis in Wistar albino male rats

Research (Published online: 17-10-2018)

12. Supplementation of whole grain flaxseeds (Linum usitatissimum) along with high cholesterol diet and its effect on hyperlipidemia and initiated atherosclerosis in Wistar albino male rats

H. Srinivasa Naik, Ch. Srilatha, K. Sujatha, B. Sreedevi and T. N. V. K. V. Prasad

Veterinary World, 11(10): 1433-1439

ABSTRACT

Background and Aim: Flaxseeds are known to have varying antihypercholesterolemic and antiatherogenic activity due to its lignan secoisolariciresinol diglucoside, alpha-linolenic acid, and omega-3 fatty acids. The beneficial effect of whole grain dietary flaxseed was evaluated experimentally in high cholesterol diet (HCD)-fed Wistar albino rats.

Materials and Methods: Male Wistar albino rats (200 g) were divided into four groups of 12 rats each. Group I rats kept as control and given basal rat chew diet, Group II as positive control for induction of hypercholesterolemia and atherosclerosis by addition of 1% cholesterol and 15% saturated edible oil to the 1000 g of standard rat chew diet (HCD), Group III rats fed with whole grain flaxseed powder at 7.5 g/kg of rat/day in the standard rat chew diet and kept as flaxseed control, and Group IV rats supplemented with flaxseed at 7.5 g/kg of rat/day along with HCD and maintained for 90 days.

Results: Group II rats revealed significantly (p<0.05) higher total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and very LDL-C and significantly (p<0.05) reduced levels of high-density lipoprotein cholesterol (HDL-C), whereas tissue antioxidants such as catalase, superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S transferase (GST) were significantly (p<0.05) reduced, and lipid peroxidation products of thiobarbituric acid reactive substances (TBARS) level were nonsignificantly (p<0.05) increased in the heart and liver tissues. Flaxseeds supplementation along with HCD significantly ameliorated the serum levels of TC, TG, LDL-C, and HDL-C along with cellular antioxidant enzymes such as catalase, SOD, GPx, GR, GST, and non-significant amelioration of TBARS in the heart and liver tissues compared to Group II rats. Majority of the histopathologically initiated atherosclerotic changes in the aorta and fatty change in the liver of Group II were not observed in the flaxseed supplemented Group IV; however, interestingly proliferation of endothelial cells with new vascular channel formation in the liver and in between cardiac muscle fibers was observed in Group I and Group IV rats.

Conclusion: The present study established the hypercholesterolemia with initiated atherosclerotic lesion in the aorta but unable to establish the atheromatous plaque in the aorta. Flaxseed supplementation along with HCD showed significant antihypercholesterolemic effect and ameliorated the changes of initiated atherosclerosis in the aorta. It needs further studies to explore all the possible beneficial effects and angiogenic properties of flaxseeds in the laboratory animals and human trials.

Keywords: atherosclerosis, flaxseeds, hepatic steatosis, hyperlipidemia, tissue antioxidants.

In vitro antibacterial effects of zinc oxide nanoparticles on multiple drug-resistant strains of Staphylococcus aureus and Escherichia coli: An alternative approach for antibacterial therapy of mastitis in sheep

Research (Published online: 16-10-2018)

11. In vitro antibacterial effects of zinc oxide nanoparticles on multiple drug-resistant strains of Staphylococcus aureus and Escherichia coli: An alternative approach for antibacterial therapy of mastitis in sheep

Myassar Alekish, Zuhair Bani Ismail, Borhan Albiss and Sara Nawasrah

Veterinary World, 11(10): 1428-1432

ABSTRACT

Aim: The aim of the study was to evaluate the antibacterial effects of zinc oxide nanoparticles (ZnO-NPs) and its possible alternative use for the treatment for mastitis in sheep and to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ZnO-NPs against multidrug-resistant Staphylococcus aureus and Escherichia coli strains isolated from subclinical mastitis cases in sheep.

Materials and Methods: A total of 50 pooled milk samples were collected from ewes with subclinical mastitis. Milk samples were cultured using standard laboratory techniques, and multidrug-resistant bacterial strains were determined using the Kirby-Bauer disk diffusion method. The MIC and MBC of ZnO-NPs were determined against isolated multidrug-resistant S. aureus and E. coli strains using microwell dilution method.

Results: A total of 43 different bacterial isolates were recovered from milk samples of ewes affected with subclinical mastitis. Isolated strains of S. aureus and E. coli were found resistant to three or more common antibacterial agents and were used to determine the MIC and MBC of ZnO-NPs. The MIC and MBC values of ZnO-NPs were significantly lower for S. aureus than that for E. coli. The MIC and MBC of ZnO-NPs against S. aureus were 3.9 μg/ml and 7.81 μg/ml, respectively, while for E. coli, the MIC and MBC of ZnO-NPs were 31.25 μg/ml and 62.5 μg/ml, respectively.

Conclusion: Results of this study indicate the potential antibacterial effects of ZnO-NPs against multidrug-resistant S. aureus and E. coli isolated from ovine subclinical mastitis at concentrations of 3.9 μg/ml and 31.25 μg/ml, respectively.

Keywords: alternative therapy, antibiotics, mastitis, nanotechnology, sheep, zinc oxide.

Detection, characterization, and antibiogram of extended-spectrum beta-lactamase Escherichia coliisolated from bovine milk samples in West Bengal, India

Research (Published online: 16-10-2018)

10. Detection, characterization, and antibiogram of extended-spectrum beta-lactamase Escherichia coliisolated from bovine milk samples in West Bengal, India

Kunal Batabyal, Abhiroop Banerjee, Susmita Pal, Samir Dey, Siddhartha Narayan Joardar, Indranil Samanta, Devi Prasad Isore and Abhishek Dharm Singh

Veterinary World, 11(10): 1423-1427

ABSTRACT

Background: Milk is considered as complete food and an important part of human diet throughout the world including India. Bacterial contamination of milk such as Escherichia coli due to unhygienic condition and poor udder health can cause infections, especially in infants and elders or in immunocompromised persons. Possession of antimicrobial resistance genes by commensal bacteria present in milk makes the issue more serious.

Aim: The study was aimed to isolate and characterize extended-spectrum beta-lactamase (ESBL)-producing E. coli from milk samples collected from different parts of West Bengal, India, to assess the potential risk associated with the food.

Materials and Methods: Around 182 milk samples were collected from apparently healthy cows reared by organized dairy farms in West Bengal. E. coli was isolated from collected samples as per standard methods followed by serotyping. The detection of ESBL-producing E. coli was done both phenotypically and genotypically by detecting the presence of blaCTX-M gene. Antibiogram of the ESBL-positive isolates was done using common 12 antibiotics by disc diffusion method.

Results: A total of 22 (12.1%) samples were found to be positive for E. coli in this study. Different serotypes such as O11, O20, O22, O34, O35, O128, O149, and UT were isolated from the collected samples. 12 (54.5%) E. coli strains showed the capability of producing ESBL, both phenotypically and genotypically with the presence of blaCTX-M gene. Antibiogram of these ESBL-positive isolates revealed the drugs such as colistin (100%), levofloxacin (83.33%), and imipenem (66.67%) to be highly sensitive against this pathogen but drugs such as cefotaxime (100%), ceftazidime (91.67%), amoxicillin/clavulanic acid (83.33%), tetracycline (75.00%), and gentamicin (58.33%) to be very much resistant.

Conclusion: More than 50% of the E. coli strains prevalent in the bovine milk samples were positive for ESBL production and are resistant to most of the common antimicrobials which may be alarming for human health.

Keywords: antibiogram, blaCTX-M, bovine milk, extended-spectrum beta-lactamase, Escherichia coli.

Effect of the combined action of Quercus cortex extract and probiotic substances on the immunity and productivity of broiler chickens

Research (Published online: 13-10-2018)

9. Effect of the combined action of Quercus cortex extract and probiotic substances on the immunity and productivity of broiler chickens

G. K. Duskaev, S. G. Rakhmatullin, N. M. Kazachkova, Y. V. Sheida, I. N. Mikolaychik, L. A. Morozova and B. H. Galiev

Veterinary World, 11(10): 1416-1422

ABSTRACT

Aim: This study was designed to investigate the synergistic effect of the combined action of probiotic bacterial strains (Bifidobacterium adolescentis and Lactobacillus acidophilus) and Quercus cortex extract as biologically active substances in the feed on the immunity and productivity of Gallus gallus domesticus.

Materials and Methods: For the experiment, 120 7-day-old broiler chickens were selected (4 groups, n=30, 3 replicates with 10 birds in each group). The groups were as follows: The reference group - basic diet (BD); experimental Group I - BD + Q. cortex extract (Q. cortex), 2.5 ml/kg of body weight; experimental Group II - BD + probiotic preparation based on B. adolescentis, 80.0 million colony-forming units (CFU), and L. acidophilus, 1.0 million CFU (dosage in accordance with the recommendations of the manufacturer); and experimental Group III - BD + probiotic + extract of Q. cortex. The following methods of study were used: Chemiluminescence and biochemical and hematological analysis.

Results: The results of the experiment showed a slight decrease in the level of leukocytes in Groups II (p≤0.05) and III, and of hemoglobin in Group III (p≤0.05), compared to the reference group. The level of alanine aminotransferase and aspartate aminotransferase in Group II was higher than both the reference group (p≤0.05) and the other groups. Introduction of Q. cortex extract into the diet increased the level of triglycerides (p≤0.05) and urea in the blood serum. The combined use of probiotic preparations and the extract resulted in an increase in the level of iron in the blood serum by 78.1% (p≤0.05) in Group III. An increase in indicators of the antioxidant system (catalase increased in Group I by 27.2% (p≤0.05) and by 3.0-12.7% in other groups; superoxide dismutase increased by 3.0-13.2%) and nonspecific immunity (β-lysine increased by 8.8-16.0%) was noted. Introduction of the extract and probiotic preparation into the diet contributed to increasing the live weight of chickens at the age of 15 days by 5.9 and 7.4%, respectively (p≤0.05). In experimental Group II, this trend continued, and by the end of the period, the weight of animals exceeded that of their peers in other groups by 0.7-7.0%. Given the high preservation rate of poultry in the II and III Groups, and the low feed consumption per 1 kg of live weight gain (by 3.1-6.7%), the efficiency of growth was higher than in the reference group.

Conclusion: Thus, the combined use of probiotic strains of bacteria and Q. cortex extract helped to increase the antioxidant activity of the organism and antimicrobial components of blood plasma compared with broiler chickens with similar growth rates but without the supplementation of this combination.

Keywords: broiler chickens, growth, plant extract, probiotic.