scholarly journals Occurrence of Virulence Genes Associated with Diarrheagenic Escherichia coli Isolated from Raw Cow’s Milk from Two Commercial Dairy Farms in the Eastern Cape Province, South Africa

2014 ◽  
Vol 11 (11) ◽  
pp. 11950-11963 ◽  
Author(s):  
Lesley-Anne Caine ◽  
Uchechukwu Nwodo ◽  
Anthony Okoh ◽  
Roland Ndip ◽  
Ezekiel Green
Author(s):  
S. Mekonnen ◽  
N.R. Bryson ◽  
L.J. Fourie ◽  
R.J. Peter ◽  
A.M. Spickett ◽  
...  

The susceptibility of the larval offspring of engorged female Boophilus decoloratus, and of the engorged females, collected from cattle on the dairy farms Brycedale, Sunny Grove and Welgevind in the Eastern Cape Province, South Africa, was tested against the acaricides amitraz, chlorfenvinphos and cypermethrin. Resistance was determined by means of the Shaw Larval Immersion Test (SLIT) for larvae and the Reproductive Estimate Test (RET) and Egg Laying Test (ELT) for adults. At Brycedale the tests all indicated resistance to chlorfenvinphos, and RET and ELT indicated resistance to amitraz and emerging resistance to cypermethrin. At Sunny Grove, B. decoloratus was resistant to cypermethrin using SLIT and exhibited emerging resistance to chlorfenvinphos with SLIT and to cypermethrin with both RET and ELT. At Welgevind, resistance was recorded against chlorfenvinphos (SLIT) and against cypermethrin (ELT), and emerging resistance against permethrin (RET). The results obtained with RET and ELT were generally comparable, but often differed from those obtained with SLIT. Resistance could be detected within 7 days with ELT compared to 42 days with RET and 60 days with SLIT.


2015 ◽  
Vol 78 (1) ◽  
pp. 72-77 ◽  
Author(s):  
ALENA SKOČKOVÁ ◽  
KATEŘINA BOGDANOVIČOVÁ ◽  
IVANA KOLÁČKOVÁ ◽  
RENÁTA KARPÍŠKOVÁ

The occurrence of antimicrobial-resistant bacteria is an important public health issue. The aim of this study was the monitoring of resistant Escherichia coli in raw cow's milk with a focus on the detection of extended-spectrum β-lactamase (ESBL)–producing strains. In total, 263 samples of raw milk from 40 farms were collected and investigated in 2010 to 2013 in the Czech Republic. Detection of E. coli was performed and evaluated according to ISO 16649-2, and antibiotic resistance was screened by the disk diffusion method. The presence of E. coli was detected in 243 (92.4%) samples. In total, 270 isolates were obtained. Resistance to β-lactam (31.8%) and tetracycline (13.0%) antibiotics was detected most often and also multiresistant strains (5.5%) were observed. E. coli isolates found to be resistant to β-lactam, tetracycline, and quinolone antibiotics were assayed by PCR to detect selected genes encoding those resistance mechanisms. In isolates in which any bla genes were detected, a double-disk synergy test was performed. ESBL production was confirmed in 2 (0.7%) isolates. The genetic analysis identified the presence of the blaCTX-M gene and other resistance genes (tet(B) and qnrB). Both ESBL-positive isolates originated from the same farm and had an identical pulsed-field gel electrophoresis profile. The findings of our study indicate that milk can be a reservoir of bacteria carrying resistance genes with a potential for spreading through the food chain.


2019 ◽  
Author(s):  
Mary Ayobami Adewoyin ◽  
Anthony Ifeanyi Okoh

Abstract Background : Several Acinetobacter species live in different ecosystems such as soil, freshwater, wastewater, and solid wastes. In this study, we assessed the occurrence of A. baumannii and A. nosocomialis , which are the major two clinically important species of the genus Acinetobacter , in three freshwater resources (Great Fish, Keiskemma, and Tyhume rivers) in the Eastern Cape Province, South Africa over a one year sampling regime (April 2017 - March 2018). Presumptive Acinetobacter species were subjected to molecular identification by using Acinetobacter genus-specific primers targeting the recA gene. The confirmed Acinetobacter species were further delineated into A. baumannii and A. nosocomialis using species-specific primer sets. Similarly, virulence genes, namely; afa/draBC, epsA, fimH, OmpA, PAI, sfa/focDE , and traT in the two Acinetobacter species were also determined using molecular techniques. Result : A total of 1107 presumptive Acinetobacter isolates were recovered from the freshwater resources of which 844 was confirmed positive for the Acinetobacter genus. Of the 844 Acinetobacter isolates, 285 (77%), 219 (70.9%) and 340 (79%) were recovered from Great Fish, Keiskemma and Tyhume rivers respectively. Our finding revealed that 410 (48.58%) and 23 (2.7%) of the isolates were confirmed to be A. baumannii and A. nosocomalis , respectively. The presence of these clinically-important Acinetobacter species in the freshwater studied suggests possible contamination of the selected rivers and also that A. baumannii and A. nosocomialis can thrive in aquatic environments. Besides, 308 (75.12%) A. baumannii and 3 (13.04%) A. nosocomialis isolates exhibited one or more virulence genes out of the seven tested, whereas 102 (24.88%) and 20 (86.95%) of the A. baumannii and A. nosocomialis isolates did not harbour any virulence gene. Additionally, OmpA was the most prevalent (p<0.05) virulence gene in A. baumannii with 69 (45.10%), 52 (50.98%) and 77 (49.68%) isolates in Great Fish, Keiskamma and Tyhume rivers respectively. Conclusion : The occurrence of these pathogens in rivers which are consumed by humans and livestock, as well as being used for irrigation system constitutes a risk to public health. Keywords: Freshwater resources, Molecular characterisation, Acinetobacter species, virulence gene s.


Author(s):  
Ezekiel Green ◽  
Abongile Pekana

Background: Staphylococcus aureus (S. aureus) occasionally threatens the life of the host as a persistent pathogen even though it is normal flora of humans and animals. We characterized drug resistance in S. aureus isolated from animal carcasses and milk samples from the abattoirs and dairy farms in the Eastern Cape Province. Methods: A 1000 meat swab samples and 200 raw milk samples were collected from selected abattoirs and dairy farms in the Eastern Cape Province, South Africa. S. aureus was isolated and positively identified using biochemical tests and confirmed by molecular methods. Antibiotic susceptibility test against 14 different antibiotics was performed against all isolates. Antibiotic resistance genes were also detected. Results: Of the 1200 samples collected, 134 (11.2%) samples were positive for S. aureus. Resistance ranged from 71.6% for penicillin G to 39.2% for tetracycline. Resistance gene (blaZ) was detected in 13 (14.9%), while msrA was found in 31 (52.5%) of S. aureus isolates. Conclusions: The present result shows the potential dissemination of multidrug-resistant S. aureus strains in the dairy farms and abattoirs in the Eastern Cape. Therefore, this implies that the organism may rapidly spread through food and pose serious public health risk


2019 ◽  
Vol 82 (12) ◽  
pp. 2194-2200 ◽  
Author(s):  
DIANA RIOS-MUÑIZ ◽  
JORGE F. CERNA-CORTES ◽  
CATALINA LOPEZ-SAUCEDO ◽  
ERIKA ANGELES-MORALES ◽  
MIRIAM BOBADILLA-del VALLE ◽  
...  

ABSTRACT In Mexico, the total milk production that family dairy farms (FDF) contribute is ca. 35%, but this milk is not evaluated for microbiological quality. Forty percent of the milk and dairy products consumed by Mexicans is unpasteurized. In total, 24 raw cow's milk samples from three FDF (one sample per each season from each FDF for two sequent years) were characterized for the presence of food quality indicator organisms, Staphylococcus aureus, Salmonella enterica, Listeria monocytogenes, and Mycobacterium spp., by standard procedures. Escherichia coli presence was also evaluated by a direct count method and diarrheagenic E. coli (DEC) by molecular methods. On the basis of Mexican guidelines for raw milk entering production, 42% of samples exceeded the aerobic mesophilic bacteria limits. A total of 83% raw milk samples were positive for total coliforms, 54% for fecal coliforms, and 46% for E. coli. Forty-three E. coli isolates were selected and characterized for the presence of 11 DEC loci; of theses, 40 isolates were negative for all DEC loci, and 3 isolates, all collected from the same sample, were Shiga toxin 2 (stx2) positive and O157 antigen negative, and one stx2 isolate was resistant to 6 of the 16 antibiotics tested. None of the 24 raw milk samples were positive for Salmonella enterica, L. monocytogenes, or staphylococcal enterotoxin. S. aureus was isolated from nine samples, of which only three samples harbored resistant isolates. From three samples, four nontuberculous mycobacterial isolates were recovered (Mycobacteroides chelonae, Mycobacteroides porcinum, and two Mycobacteroides abscessus). All four isolates produced biofilm and had sliding motility, and three isolates (M. porcinum and two M. abscessus) were resistant to the two antibiotics tested (clarithromycin and linezolid). FDF provide raw milk to a large proportion of the Mexican population, but its consumption could be harmful to health, emphasizing the need to implement national microbiological quality guidelines for raw milk intended for direct human consumption. HIGHLIGHTS


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