Screening method for Staphylococcus aureus identification in subclinical bovine mastitis from dairy farms

Research (Published online: 01-07-2017)

1. Screening method for Staphylococcus aureus identification in subclinical bovine mastitis 

from dairy farms

Natapol Pumipuntu, Suphang Kulpeanprasit, Sirijan Santajit, Witawat Tunyong, Thida Kong-ngoen, 

Woranich Hinthong and Nitaya Indrawattana

Veterinary World, 10(7): 721-726

ABSTRACT

Background: Staphylococcus aureus is one of the most important contagious bacteria causing subclinical bovine mastitis. This bacterial infection is commonly identified by determine the pathogen in bovine milk samples through conventional technique including coagulase test. However, this test has several disadvantages as low sensitivity, risk of biohazard, cost expensive, and limited preparation especially in local area.

Aim: Aim of this study was to compare and assess the screening method, Mannitol fermentation test (Mannitol salt agar [MSA]), and deoxyribonuclease (DNase) test, for S. aureus identification in milk samples.

Materials and Methods: A total of 224 subclinical bovine mastitis milk samples were collected from four provinces of Thailand and determined S. aureus using conventional method and also subjected to the screening test, MSA and DNase test. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) among both tests were analyzed and compared to the tube coagulase test (TCT), as reference method. Immunological test by latex agglutination and molecular assay by determined spa gene were also used to identify and differentiate S. aureus.

Results: A total of 130 staphylococci were isolated by selective media, Gram-stain, and catalase test. The number of S. aureus which identified using TCT, MSA and DNase test were 32, 102, and 74 isolates, respectively. All TCT results were correlated to results of latex agglutination and spa gene which were 32 S. aureus. MSA showed 100% sensitivity, 28.57% specificity, 31.37% PPV, and 100% NPV, whereas DNase showed 53.13% sensitivity, 41.84% specificity, 22.97% PPV, and 73.21% NPV. DNase test showed higher specificity value than MSA but the test presented 26.79% false negative results whereas no false-negative result from MSA when comparing to TCT.

Conclusion: MSA had a tendency to be a good preference for screening S. aureus because of its high sensitivity and NPV. The result from this study will improve a choice to use a screening test to diagnose S. aureus of veterinary field for prompt disease controlling and effective treatment.

Keywords: bovine mastitis, deoxyribonuclease test, mannitol fermentation test, screening methods, Staphylococcus aureus.

Virulence gene profiles of Arcobacter species isolated from animals, foods of animal origin, and humans in Andhra Pradesh, India

Research (Published online: 30-06-2017)

23. Virulence gene profiles of Arcobacter species isolated from animals, foods of animal origin, and humans in Andhra Pradesh, India

M. Soma Sekhar, S. R. Tumati, B. K. Chinnam, V. S. Kothapalli and N. Mohammad Sharif

Veterinary World, 10(6): 716-720

ABSTRACT

Aim: This study aimed to detect putative virulence genes in Arcobacter species of animal and human origin.

Materials and Methods: A total of 41 Arcobacter isolates (16 Arcobacter butzleri, 13 Arcobacter cryaerophilus, and 12 Arcobacter skirrowii) isolated from diverse sources such as fecal swabs of livestock (21), raw foods of animal origin (13), and human stool samples (7) were subjected to a set of six uniplex polymerase chain reaction assays targeting Arcobacter putative virulence genes (ciaB, pldA, tlyA, mviN, cadF, and cj1349).

Results: All the six virulence genes were detected among all the 16 A. butzleri isolates. Among the 13 A. cryaerophilus isolates, cadF, ciaB, cj1349, mviN, pldA, and tlyA genes were detected in 61.5, 84.6, 76.9, 76.9, 61.5, and 61.5% of isolates, respectively. Among the 12 A. skirrowii isolates, cadF, ciaB, cj1349, mviN, pldA, and tlyA genes were detected in 50.0, 91.6, 83.3, 66.6, 50, and 50% of isolates, respectively.

Conclusion: Putative virulence genes were detected in majority of the Arcobacter isolates examined. The results signify the potential of Arcobacter species as an emerging foodborne pathogen.

Keywords: Arcobacter, Arcobacter butzleri, Arcobacter cryaerophilus, Arcobacter skirrowii, polymerase chain reaction, virulence genes.

Honey can repairing damage of liver tissue due to protein energy malnutrition through induction of endogenous stem cells

Research (Published online: 29-06-2017)

22. Honey can repairing damage of liver tissue due to protein energy malnutrition through induction 

of endogenous stem cells

R. Heru Prasetyo and Eka Pramyrtha Hestianah

Veterinary World, 10(6): 711-715

ABSTRACT

Aim: This study was to evaluate effect of honey in repairing damage of liver tissue due to energy protein malnutrition and in mobilization of endogenous stem cells.

Materials and Methods: Male mice model of degenerative liver was obtained through food fasting but still have drinking water for 5 days. It caused energy protein malnutrition and damage of liver tissue. The administration of 50% (v/v) honey was performed for 10 consecutive days, while the positive control group was fasted and not given honey and the negative control not fasted and without honey. Observations of regeneration the liver tissue based on histologically examination, observation of Hsp70 expression, and homing signal based on vascular endothelial growth factor-1 (VEGF-1) expression using immunohistochemistry technique. Observation on expression of CD34 and CD45 as the marker of auto mobilization of hematopoietic stem cells using flow cytometry technique.

Results: There is regeneration of the liver tissue due to protein energy malnutrition, decrease of Hsp70 expression, increase of VEGF-1 expression, and high expression of CD34 and CD45.

Conclusion: Honey can improve the liver tissue based on: (1) Mobilization of endogenous stem cells (CD34 and CD45); (2) Hsp70 and VEGF-1 expressions as regeneration marker of improvement, and (3) regeneration histologically of liver tissue.

Keywords: endogenous stem cells, honey, liver tissue, protein energy malnutrition, regeneration.

Tetracycline resistance phenotypes and genotypes of coagulase-negative staphylococcal isolates from bubaline mastitis in Egypt

Research (Published online: 25-06-2017)

21. Tetracycline resistance phenotypes and genotypes of coagulase-negative staphylococcal 

isolates from bubaline mastitis in Egypt

K. A. Abd El-Razik, A. A. Arafa, R. H. Hedia and E. S. Ibrahim

Veterinary World, 10(6): 702-710

ABSTRACT

Aim: This study was devoted to elucidate the tetracycline resistance of coagulase-negative staphylococci (CNS) derived from normal and subclinical mastitic (SCM) buffaloes' milk in Egypt.

Materials and Methods: A total of 81 milk samples from 46 normal buffalo milk samples and 35 SCM buffalo milk samples at private dairy farms of Egypt were used in this study. CNS were identified using phenotypic and molecular methods (polymerase chain reaction [PCR]). CNS isolates were tested for tetracycline resistance using routine methods and multiplex PCR targeting tetracycline (tet) resistance genes followed by sequencing of positive PCR products and phylogenetic analysis.

Results: Isolation and identification of 28 (34.5%) CNS from normal and SCM buffaloes' milk, namely, Staphylococcus intermedius (39.2%), Staphylococcus xylosus (25.0%), Staphylococcus epidermidis (10.7%), Staphylococcus hominis (10.7%), and 3.5% to each of Staphylococcus sciuri, Staphylococcus hyicus, Staphylococcus lugdunensis, and Staphylococcus simulans. Using nested PCR, all the 28 CNS isolates revealed positive for 16srRNA gene specific for genus staphylococci and negative for thermonuclease (nuc) gene specific for Staphylococcus aureus species. The presence of tetracycline resistance-encoding genes (tetK, tetL, tetM, and tetO) was detected by multiplex PCR. All isolates were negative for tetL, M, and O genes while 14 (50%) CNS isolates were positive for tetK gene, namely, S. lugdunensis (100%), S. hominis (100%), S. epidermidis (66.6%), S. intermedius(45.4%), and S. xylosus (42.8%). Nucleotide sequencing of tetK gene followed by phylogenetic analysis showed the high homology between our CNS isolates genes of tetracycline resistance with S. aureus isolates including Egyptian ones. This proves the transfer of the tetracycline resistance encoding genes between coagulase-negative and coagulase-positive Staphylococcus spp.

Conclusion: CNS isolates have distinguishingly high resistance to tetracycline. Abundant tetracycline usage for mastitis treatment leads to the spread of genetic resistance mechanisms inside CNS strains and among all Staphylococcus spp. Consequently, tetracycline is not effective anymore.

Keywords: buffaloes, coagulase-negative staphylococci, mastitis, tetracycline resistance, tetK gene.

Investigation of avian influenza infection in wild birds in Ismailia and Damietta cities, Egypt

Research (Published online: 25-06-2017)

20. Investigation of avian influenza infection in wild birds in Ismailia and Damietta cities, Egypt

Hanaa Mohamed Fadel and Rabab Afifi

Veterinary World, 10(6): 695-701

ABSTRACT

Aim: This study was carried out to monitor avian influenza (AI) infection in wild birds in Egypt.

Materials and Methods: A total of 135 wild birds were examined for the presence of H5, H7, and H9 hemagglutination inhibition antibodies. Organs and swab samples of 75 birds were screened by multiplex real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) to detect AI subtypes H5, H7, and H9 matrix genes.

Results: The highest seropositive result was recorded in cattle egrets (90.9%) followed by crows (88.6%), semi-captive pigeons (44.8%), and moorhens (39.1%). In cattle egrets, semi-captive pigeons and moorhens, H5 antibodies predominated. In crows, H9 antibodies predominated. Multiple infections with two or three virus subtypes were highest in crows (6/39, 15.4%) followed by cattle egrets (3/30, 10%) and moorhens' (1/9, 11.1%) positive samples. Multiplex RRT-PCR results revealed two positive samples in cattle egrets and moorhens.

Conclusion: The results indicated high seropositive rates against AI virus subtypes H5 and H9 in the examined wild birds. Multiple infections with more than one AI virus (AIV) subtypes were detected in some birds. This requires a collaboration of efforts to monitor AIV infection in wild birds and implement suitable early intervention measures.

Keywords: avian influenza, hemagglutination inhibition, real-time reverse transcriptase-polymerase chain reaction, wild birds.

Epidemiological study of tick infestation in buffalo of various regions of district Khairpur, Pakistan

Research (Published online: 24-06-2017)

19. Epidemiological study of tick infestation in buffalo of various regions of district Khairpur, Pakistan

Farzana Abbasi, Imtiaz Hussain Raja Abbasi, Tahmeena Fakhur Nissa, Zohaib Ahmed Bhutto, Muhammed Asif Arain, Rab Nawaz Soomro, Farman Ali Siyal and Sarfraz Ali Fazlani

Veterinary World, 10(6): 688-694

doi: 10.14202/vetworld.2017.688-694

Abstract

Aim: The aim of this study was to determine the epidemiological infestation and identification of Ixodidae and Argasidae ticks species in buffalo of different parts of district Khairpur, Pakistan.

Materials and Methods: A total of 720 Water buffaloes from three tehsils (subdivisions) were selected randomly and examined from organized and unorganized dairy farms for tick infestation in district Khairpur, Pakistan. This epidemiological survey was conducted during April to September 2015.

Results: The overall mean population and preferred site of tick attachment to infested animals, in Gambat, Sobhodero, and Kot Diji tehsils, were observed on different body parts. The primary body area of infestation by ticks (head, thorax, abdomen, udder, and tail) ranged from highest in tail and udder part compared to lowest in the abdomen, head, and thorax. In all study areas, the infestation was higher (p<0.05) in tail and udder than other parts of the body. In all the study areas, the overall highest population was found in the month of July. In addition, we first time identify four new species of ticks (Hyalomma anatolicum, H. anatolicum excavatum, Hyalomma Ixodes excavatum, and Ixodes ricinus) in district Khairpur, Pakistan.

Conclusion: Results of this study provide additional information of epidemiological tick infestation, and will be helpful for evolving effective control policy for the management of tick infestation in study district.

Keywords: Argasidae, buffalo, identification, Ixodidae, population, prevalence, ticks, tick infestation.

Th1/Th2 balance and humoral immune response to potential antigens as early diagnostic method of equine Strongylus nematode infection

Research (Published online: 24-06-2017)

18. Th1/Th2 balance and humoral immune response to potential antigens as early diagnostic method of equine Strongylus nematode infection

Faten A. M. Abo-Aziza, Seham H. M. Hendawy, Amira H. El Namaky and Heba M. Ashry

Veterinary World, 10(6): 679-687

doi: 10.14202/vetworld.2017.679-687

Abstract

Aim: The aim of this study was to investigate the early diagnosis of strongyle infection based on early changes in Th1 and Th2 cytokines beside the diagnostic accuracy values and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting profiles using prepared strongyles antigens.

Materials and Methods: A total of 73 donkeys had a mean age of 4-32 years old were parasitologically examined for strongyle infection. The early changes in Th1 and Th2 cytokines were determined, and the diagnostic accuracy values and SDS-PAGE and western blotting profiles were performed using prepared strongyles antigens; crude somatic Strongylus vulgaris (CSS), excretory-secretory S. vulgaris (ESS), crude somatic Cyathostomins (CSC), and excretory-secretory Cyathostomins (ESC).

Results: The results revealed highest 437.04% and lowest 37.81% immunoglobulin G (IgG) in high and low egg shedder groups when using ESC and CSS antigens, respectively. Antibodies index for ESS and CSC were significantly higher in moderate egg shedder group while that for ESS and CSC, ESC was significantly higher in high egg shedder group. Tumor necrosis factor alpha (TNF-α)/interleukin-4 (IL-4) balance in S. vulgaris infected donkeys was approximately equal in apparently healthy, low and high egg shedder groups while TNF-α < IL-4 in moderate egg shedder. In Cyathostomins infected animals, TNF-α/IL-4 balance was approximately equal in apparently healthy group while it was low in moderate and high egg shedder groups. The diagnostic accuracy showed that the higher specificity (46.6%) and prevalence (95.40%) were recorded by CSS and ESC antigens, respectively. However, SDS-PAGE and western blotting profiling proved that the band at molecular weight 25 kDa is exhibited by CSS antigen.

Conclusion: Combination of detecting level of TNF-α/IL-4 balance, CSS antigen and IgG concentration is good tool for appropriate diagnosis of such infection. More advancement research must be done concerning Th1/Th2 balance and cross-reactivity of S. vulgaris and Cyathostomins spp. at the base of serological and molecular investigation.

Keywords: cytokines, interleukin-4, Strongylus, Th1, Th2, tumor necrosis factor alpha.