Surveillance of antimicrobial resistance of maltose negative Staphylococcus aureus in South African dairy herds

Abstract BackgroundThe discovery of antimicrobials in the 1930s was one of the greatest achievements in medicine. However, bacterial resistance to antimicrobials was already observed in the 1940s and has been reported since then in both human and veterinary medicine, including in dairy cows. Many years of monitoring milk samples in South Africa, has led to the identification of a new strain of Staphylococcus aureus (S. aureus), which is maltose negative and appears to be an emerging pathogen. In this study the differences in susceptibility to antimicrobials of this strain were evaluated over time, over different seasons, in different provinces, and according to somatic cell count (SCC) categories.Results A data set of 271 maltose negative S. aureus isolates, cultured from milk samples from 117 herds out of the estimated 2000 commercial dairy herds in South Africa between 2010 and 2017, was studied using the disc diffusion method. This analysis was done using the Clinical Laboratory Standards Institute (CLSI) breakpoints in order to compare using both the previously used system (intermediate category grouped with resistant) and more recent system, (intermediate category grouped with susceptible). The results between the previously used system and the more recent system analysis differed for tylosin, cefalonium, oxy-tetracycline and cloxacillin. Neither the analysis using the previous system nor the more recent system showed an effect of province for the maltose negative S. aureus. This was in contrast to the results for maltose positive S. aureus where differences between provinces were shown in a previous study. For the susceptibility testing of 57 maltose negative S. aureus and 57 maltose positive S. aureus the minimum inhibitory concentration (MIC) results for the maltose negative S. aureus confirmed the results of the disc diffusion method. ConclusionsThe maltose negative strains of S. aureus differed in general, in their antimicrobial resistance patterns over time, in comparison to maltose-positive S. aureus strains. MIC testing also indicated that more multi-resistant isolates were seen with the maltose negative S. aureus than in the maltose positive strains.

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Surveillance of antimicrobial resistance of maltose negative Staphylococcus aureus in South African dairy herds

10.21203/rs.2.18013/v3 ◽

2020 ◽

Author(s):

Joanne Karzis ◽

Inge-Marié Petzer ◽

Edward F. Donkin ◽

Vinny Naidoo ◽

Eric M. C. Etter

Keyword(s):

South Africa ◽

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Disk Diffusion ◽

Diffusion Method ◽

Dairy Herds ◽

Disk Diffusion Method ◽

Milk Samples ◽

Kwazulu Natal ◽

Over Time

Abstract Background The discovery of antimicrobials in the 1930s was one of the greatest achievements in medicine. However, bacterial resistance to antimicrobials was already observed in the 1940s and has been reported since then in both human and veterinary medicine, including in dairy cows. Many years of monitoring milk samples in South Africa, has led to the identification of a new strain of Staphylococcus aureus (S. aureus), which is maltose negative and appears to be an emerging pathogen. In this study the differences in susceptibility to antimicrobials of this strain were evaluated over time, over different seasons, in different provinces, and according to somatic cell count (SCC) categories. Results A data set of 271 maltose negative S. aureus isolates, cultured from milk samples from 117 herds out of the estimated 2000 commercial dairy herds in South Africa between 2010 and 2017, was studied using the disk diffusion method. This analysis was done using the Clinical Laboratory Standards Institute (CLSI) breakpoints in order to compare using both the previous (Intermediate category grouped with Resistant) and current definitions, (Intermediate category grouped with Susceptible). The results of the analysis between the previous and the current definitions differed for tylosin, cefalonium, oxy-tetracycline and cloxacillin. Neither the analysis using the previous nor the current systems showed an effect of province for the maltose negative S. aureus. This was in contrast to the results for maltose positive S. aureus where differences between provinces were shown in a previous study, with the lowest prevalence of resistance shown in KwaZulu-Natal during spring. For the susceptibility testing of 57 maltose negative and 57 maltose positive S. aureus isolates from 38 farms, from KwaZulu Natal, Eastern Cape and Western Cape. The minimum inhibitory concentration (MIC) results for the maltose negative S. aureus isolates confirmed the results of the disk diffusion method. Conclusions The maltose negative strains of S. aureus differed in general, in their antimicrobial resistance patterns over time, in comparison to maltose-positive S. aureus strains. MIC testing also indicated that more multidrug -resistant isolates were seen with the maltose negative S. aureus than in the maltose positive strains.

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Surveillance of antimicrobial resistance of maltose negative Staphylococcus aureus in South African dairy herds

10.21203/rs.2.18013/v2 ◽

2020 ◽

Author(s):

Joanne Karzis ◽

Inge-Marié Petzer ◽

Edward F. Donkin ◽

Vinny Naidoo ◽

Eric M. C. Etter

Keyword(s):

South Africa ◽

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Disk Diffusion ◽

Diffusion Method ◽

Dairy Herds ◽

Disk Diffusion Method ◽

Milk Samples ◽

Kwazulu Natal ◽

Over Time

Abstract Background The discovery of antimicrobials in the 1930s was one of the greatest achievements in medicine. However, bacterial resistance to antimicrobials was already observed in the 1940s and has been reported since then in both human and veterinary medicine, including in dairy cows. Many years of monitoring milk samples in South Africa, has led to the identification of a new strain of Staphylococcus aureus (S. aureus), which is maltose negative and appears to be an emerging pathogen. In this study the differences in susceptibility to antimicrobials of this strain were evaluated over time, over different seasons, in different provinces, and according to somatic cell count (SCC) categories. Results A data set of 271 maltose negative S. aureus isolates, cultured from milk samples from 117 herds out of the estimated 2000 commercial dairy herds in South Africa between 2010 and 2017, was studied using the disk diffusion method. This analysis was done using the Clinical Laboratory Standards Institute (CLSI) breakpoints in order to compare using both the previous (Intermediate category grouped with Resistant) and current definitions, (Intermediate category grouped with Susceptible). The results of the analysis between the previous and the current definitions differed for tylosin, cefalonium, oxy-tetracycline and cloxacillin. Neither the analysis using the previous nor the current systems showed an effect of province for the maltose negative S. aureus. This was in contrast to the results for maltose positive S. aureus where differences between provinces were shown in a previous study, with the lowest prevalence of resistance shown in KwaZulu-Natal during spring. For the susceptibility testing of 57 maltose negative and 57 maltose positive S. aureus isolates from 38 farms, from KwaZulu Natal, Eastern Cape and Western Cape. The minimum inhibitory concentration (MIC) results for the maltose negative S. aureus isolates confirmed the results of the disk diffusion method. Conclusions The maltose negative strains of S. aureus differed in general, in their antimicrobial resistance patterns over time, in comparison to maltose-positive S. aureus strains. MIC testing also indicated that more multidrug -resistant isolates were seen with the maltose negative S. aureus than in the maltose positive strains.

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Surveillance of Antibiotic Resistance of Maltose-Negative Staphylococcus aureus in South African Dairy Herds

Antibiotics ◽

10.3390/antibiotics9090616 ◽

2020 ◽

Vol 9 (9) ◽

pp. 616

Author(s):

Joanne Karzis ◽

Inge-Marié Petzer ◽

Edward F. Donkin ◽

Vinny Naidoo ◽

Eric M.C. Etter

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

South African ◽

Inhibitory Concentration ◽

Aureus Strain ◽

Diffusion Method ◽

Dairy Herds ◽

Disk Diffusion Method ◽

Data Set ◽

Milk Samples

Antibiotic resistance has been reported since the 1940s in both human and veterinary medicine. Many years of monitoring milk samples in South Africa led to identification of a novel maltose-negative Staphylococcus aureus (S. aureus) strain, which appears to be an emerging pathogen. In this study, the susceptibility of this strain to antibiotics was evaluated over time, during diverse seasons in various provinces and according to somatic cell count (SCC) categories. A data set of 271 maltose-negative S. aureus isolates, from milk samples of 117 dairy herds, was examined using the disk diffusion method, between 2010 and 2017. This study also compared the susceptibility testing of 57 maltose-negative and 57 maltose-positive S. aureus isolated from 38 farms, from three provinces using minimum inhibitory concentration (MIC). The MIC results for the maltose-negative S. aureus isolates showed highest resistance to ampicillin (100%) and penicillin (47.4) and lowest resistance (1.8%) to azithromycin, ciprofloxacin and erythromycin. The maltose-negative S. aureus isolates showed overall significantly increased antibiotic resistance compared to the maltose-positive strains, as well as multidrug resistance. Producers and veterinarians should consider probability of cure of such organisms (seemingly non-chronic) when adapting management and treatment, preventing unnecessary culling.

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Prevalence of methicillin-resistant Staphylococcus aureus and pattern of antimicrobial resistance in mastitis milk of cattle in Chitwan, Nepal

BMC Veterinary Research ◽

10.1186/s12917-021-02942-6 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Asmita Shrestha ◽

Rebanta Kumar Bhattarai ◽

Himal Luitel ◽

Surendra Karki ◽

Hom Bahadur Basnet

Keyword(s):

Public Health ◽

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Subclinical Mastitis ◽

World Health ◽

Dairy Herds ◽

Microbiological Analysis ◽

Biochemical Tests ◽

Methicillin Resistant ◽

Milk Samples

Abstract Background The threat of methicillin-resistant Staphylococcus aureus (MRSA) exists globally and has been listed as a priority pathogen by the World Health Organization. One of the sources of MRSA emergence is livestock and its products, often raised in poor husbandry conditions. There are limited studies in Nepal to understand the prevalence of MRSA in dairy animals and its antimicrobial resistance (AMR) profile. A cross-sectional study was conducted in Chitwan, one of the major milk-producing districts of Nepal, from February 2018 to September 2019 to estimate the prevalence of MRSA in milk samples and its AMR profile. The collected milk samples (n = 460) were screened using the California Mastitis Test (CMT) and positive samples were subjected to microbiological analysis to isolate and identify S. aureus. Polymerase Chain Reaction (PCR) was used to identify the presence of the mecA gene and screen for MRSA. Results In total, 41.5% (191/460) of milk samples were positive in the CMT test. Out of 191 CMT positive milk samples, the biochemical tests showed that the prevalence of S. aureus was 15.2% (29/191). Among the 29 S. aureus isolates, 6.9% (2/29) were identified as MRSA based on the detection of a mecA gene. This indicates that that 1.05% (2/191) of mastitis milk samples had MRSA. The antibiotic sensitivity test showed that 75.9% (22/29) and 48.3% (14/29) S. aureus isolates were found to be sensitive to Cefazolin and Tetracycline respectively (48.3%), whereas 100% of the isolates were resistant to Ampicillin. In total 96.6% (28/29) of S. aureus isolates were multidrug-resistant (MDR). Conclusions This study revealed a high prevalence of S. aureus-mediated subclinical mastitis in dairy herds in Chitwan, Nepal, with a small proportion of it being MRSA carrying a mecA gene. This S. aureus, CoNS, and MRSA contaminated milk poses a public health risk due to the presence of a phenotype that is resistant to very commonly used antibiotics. It is suggested that dairy herds be screened for subclinical mastitis and treatments for the animals be based on antibiotic susceptibility tests to reduce the prevalence of AMR. Furthermore, future studies should focus on the Staphylococcus spp. to explore the antibiotic resistance genes in addition to the mecA gene to ensure public health.

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Interpretive criteria to differentiate low- and high-level mupirocin resistance in Staphylococcus aureus

Journal of Medical Microbiology ◽

10.1099/jmm.0.46965-0 ◽

2007 ◽

Vol 56 (7) ◽

pp. 937-939 ◽

Cited By ~ 24

Author(s):

Naira Elane Moreira de Oliveira ◽

Ana Paula Couto Marques Cardozo ◽

Elizabeth de Andrade Marques ◽

Kátia Regina Netto dos Santos ◽

Marcia Giambiagi deMarval

Keyword(s):

Staphylococcus Aureus ◽

High Resistance ◽

The Other ◽

Diffusion Method ◽

Disc Diffusion ◽

Disc Diffusion Method ◽

Zone Diameter ◽

Resistant Strains ◽

Mupirocin Resistance ◽

High Level

Meticillin-resistant Staphylococcus aureus isolates were classified into three mupirocin susceptibility groups by the disc diffusion method using 5 and 200 μg mupirocin discs. The zone diameter observed for a 5 μg disc distinguished MupS from the resistant strains (either MupRL or MupRH). On the other hand, a 200 μg disc distinguished the high-resistance MupRH strains from the other two (MupS or MupRL). Thus, the concomitant use of 5 and 200 μg mupirocin discs allowed the clear distinction among the three mupirocin susceptibility groups, MupS, MupRL or MupRH.

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Screening of the antimicrobial activity of marine sponge extracts from Martinique

10.1101/2021.02.16.431398 ◽

2021 ◽

Author(s):

Julie Piron ◽

Jessica Pastour ◽

Niklas Tysklind ◽

Juliette Smith-Ravin ◽

Fabienne Priam

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Activity ◽

Inhibitory Concentration ◽

Minimum Bactericidal Concentration ◽

Marine Sponges ◽

Diffusion Method ◽

Disc Diffusion ◽

Bacterial Strains ◽

Disc Diffusion Method ◽

Staphylococcus Saprophyticus

AbstractMarine sponges are known for their antimicrobial, antifungal, and cytotoxic activity. In this study, the activity of aqueous and ethanoic extracts of 3 sponges from Martinique were tested on 5 bacterial strains: Bascillus cereus (CIP 783), Echerichia coli (CIP 54127), Pseudomonas aeruginosa (CIP A22), Staphylococcus aureus (CIP 67.8) and Staphylococcus saprophyticus (CIP 76125). The antimicrobial activity of Agelas clathrodes, Desmapsamma anchorata, and Verongula rigida, was demonstrated using the disc diffusion method and by determining the minimum inhibitory concentration and the minimum bactericidal concentration. The ethanoic extract of Agelas clathrodes had an inhibitory activity specifically on Staphylococcus aureus and Staphylococcus saprophyticus. No activity was observed for the other extracts. Further chemical analyses will be carried out in order to identify the active molecules of these sponges.

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Isolation, Characterization and Antibacterial Activity of Ergosta-5, 7, 22-triene-3β, 14α – diol (22Z) from Kenyan Ganoderma lucidum

Asian Journal of Applied Chemistry Research ◽

10.9734/ajacr/2020/v5i130127 ◽

2020 ◽

pp. 48-57

Author(s):

Ebrahim Sande ◽

Danstone Lilechi Baraza ◽

Selline Ooko ◽

Peter Kuloba Nyongesa

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Streptococcus Pyogenes ◽

Ganoderma Lucidum ◽

Methicillin Resistance ◽

Hexane Extract ◽

Diffusion Method ◽

Significant Activity ◽

Disc Diffusion ◽

Disc Diffusion Method

Aims: To determine the chemical composition and antibacterial activity of Kenyan Ganoderma lucidum. Study Design: Structural determination of the isolated compound was done using spectral evidences and in comparison with literature. The antibacterial properties of the compound was done using disc diffusion method. Place and Duration of Study: Department of Pure and Applied Chemistry, Masinde Muliro University of Science and Technology, between January and November, 2019. Methodology: Sequential extraction of dried samples of Kenyan G. lucidum were done using solvents hexane, ethyl acetate and methanol. Chromatographic separation of hexane extract of Ganoderma lucidum was done using spectroscopic data. The compound was assayed against Escherichia coli, Klebsiella pneumoniae, Methicillin–Resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Streptococcus pyogenes. Standard antibiotic namely; ampicillin was used as the control. Disc diffusion method was used and zones of inhibition, after respective incubation periods, were used to quantify antibacterial activity. Results: From hexane extract of Ganoderma lucidum, Ergosta-5, 7, 22-triene-3β, 14α – diol (22Z) was isolated. Ethylacetate and methanol extracts produced a mixture of complex compounds. Ergosta-5,7,22-triene-3β,14α-diol (22Z) exhibited significant activity against Methicillin-Resistance Staphylococcus aureus (MRSA) (p=0.022) and Streptococcus pyogenes (p = 0.05). The most sensitive microbe was Streptococcus pyogenes. Conclusion: One major compound, Ergosta-5, 7, 22-triene-3β, 14α – diol (22Z) was isolated, characterized and antibacterial activity determined.

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Antimicrobial Activity of some Honey Samples against Pathogenic Bacteria

International Letters of Natural Sciences ◽

10.18052/www.scipress.com/ilns.34.15 ◽

2015 ◽

Vol 34 ◽

pp. 15-20 ◽

Cited By ~ 4

Author(s):

S. Mahendran ◽

D. Kumarasamy

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Activity ◽

Antibacterial Activity ◽

Streptococcus Pyogenes ◽

Western Ghats ◽

Pathogenic Bacteria ◽

Research Work ◽

Diffusion Method ◽

Disc Diffusion ◽

Disc Diffusion Method

The aim of the present research work to investigate antimicrobial activity of some honey samples six winter honeys six summer honeys collected from different regions of Western Ghats. The microbes used in this study are Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis. Antibacterial activity of the honeys was assayed using the Disc diffusion method. Noticeable variations in the antibacterial activity of the different honey samples were observed. Among the microbes Staphylococcus aureus is the most sensitive against all honey samples shows the maximum inhibitor zone compare to summer honeys.

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Antimicrobial resistance of non-clinical Escherichia coli strains from chicken in Nsukka, South-east Nigeria.

Nigerian Journal of Animal Production ◽

10.51791/njap.v30i1.1840 ◽

2021 ◽

Vol 30 (1) ◽

pp. 101-106

Author(s):

K. F. Chah ◽

S. C. Okafor ◽

S. I. Oboegbulem

Keyword(s):

Escherichia Coli ◽

Drug Resistance ◽

Antimicrobial Resistance ◽

Antimicrobial Agents ◽

Diffusion Method ◽

Disc Diffusion ◽

Disc Diffusion Method ◽

E Coli ◽

Sensitivity Tests ◽

Resistance Patterns

This study was carried out to determine resistance profiles of Escherichia coli strains isolated from clinically healthy chickens in Nsukka, southeast Nigeria. A total of 324 E. coli strains isolated from cloaca swabs from 390 chickens were tested against 16 antimicrobial agents using the disc diffusion method. The antibiotics used in the study were: ampicillin (25µg), amoxycillin-clavulanic acid (30µg), gentamicin (10µg), Streptomycin (30µg). cefuroxime (20µg), cephalexin (10µg), nalidixic acid (30µg), ciprofloxacin (5µg), norfloxacin (10µg), ofloxacin (5µg), pefloxacin (5µg), tetracycline (30µg), chloramphenicol (10µg), cotrimoxazole (50µg), colistin (25µg) and nitrofurantoin (100µg).The strains demonstrated high rates of resistance (34.6% 66.1%) to ampicillin, tetracycline, nitrofurantoin, cefuroxime and cotrimoxazole. None of the isolates was resistant to colistin, ofloxacin and pefloxacin. For each antimicrobial agent (except cephalexin), strains from the intensively reared chickens (layers and broilers) displayed higher resistance frequencies than those from the local birds. A total of 49 resistant patterns were recorded for the 228 strains resistant to at least one antimicrobial drug, with AmTeCoS and AmTeCfN being the predominant patterns. Because of the great variation in the drug resistance patterns of the Escherichia coli strains, use of antimicrobial agents in the management of E. coli infections in the study area should be based on results of sensitivity tests.

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