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

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 616
Author(s):  
Joanne Karzis ◽  
Inge-Marié Petzer ◽  
Edward F. Donkin ◽  
Vinny Naidoo ◽  
Eric M.C. Etter

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.

Author(s):  
Negin Momtaz Bokharaei ◽  
Zahra Rajabi ◽  
MohammadMehdi Soltan Dallal

Introduction:Staphylococcal food poisoning is one of the most common food-borne diseases. The antibiotic resistance of Staphylococcus aureus has been reported globally. Today, strains of Staphylococcus aureus in food have become a problem in clinical infections and are considerde as a serious public health concern. Methods: A total of 100 samples were tested in the laboratory; including 75 handmade and 25 industrial hamburger samples. The Staphylococcus aureus samples were isolated and identified according to the National Iranian Standard No. 6806-3. Antibiotic resistance was determined by disk diffusion method and minimum inhibitory concentration was performed. In this study, the antibiotics penicillin, ciprofloxacin, erythromycin, clindamycin, chloramphenicol, cefoxitin, trimethoprim-sulfamethoxazole, tetracycline, gentamicin, vancomycin, and oxacillin were used. Results: Of 100 analyzed hamburger samples, 39 samples were infected with Staphylococcus aureus (23 industrial and 16 ­ handmade samples). All isolates of Staphylococcus aureus (100%) were susceptible to gentamicin and vancomycin antibiotics. Conclusions: Due to the importance of Staphylococcus aureus, as the supergene antigen and its role in causing food poisoning, contamination of foodstuffs with Staphylococcus aureus can threaten the consumers' health.


2020 ◽  
Author(s):  
Joanne Karzis ◽  
Inge-Marié Petzer ◽  
Edward F. Donkin ◽  
Vinny Naidoo ◽  
Eric M. C. Etter

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.


2019 ◽  
Author(s):  
Joanne Karzis ◽  
Inge-Marié Petzer ◽  
Edward F. Donkin ◽  
Vinny Naidoo ◽  
Eric M. C. Etter

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.


2020 ◽  
Author(s):  
Joanne Karzis ◽  
Inge-Marié Petzer ◽  
Edward F. Donkin ◽  
Vinny Naidoo ◽  
Eric M. C. Etter

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.


Author(s):  
Abolfazl Jafari-Sales ◽  
Zahra Sadeghi Deylamdeh ◽  
Afsoon Shariat

Introduction: Staphylococcus aureus causes a wide range of infections and as a multivalent pathogen is one of the causative agents of nosocomial and community infections. Therefore, the aim of this study was to identify and determine the pattern of antibiotic resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients in hospitals and medical centers in Marand city and also to evaluate the presence of mecA gene. Materials and Methods: In this cross-sectional descriptive study, 385 samples of S. aureus were collected from different clinical samples of patients in hospitals and medical centers of Marand city. S. aureus was identified using standard biochemical methods.  Methicillin resistance was determined by disk diffusion method in the presence of oxacillin and cefoxitin. The pattern of antibiotic resistance of the strains was determined by disk diffusion method and according to CLSI recommendation and also PCR method was used to evaluate the frequency of MecA gene. Results: In the present study, out of 385 samples of S. aureus, 215 (55.84%) samples were methicillin resistant. PCR results for mecA gene showed that 110 samples had mecA gene.  The highest antibiotic resistance was observed against penicillin (100%) and erythromycin (83.63%). Most MRSA were isolated from urine and wound samples. Conclusion: The results of this study indicate the prevalence of methicillin-resistant species and also the increase in antibiotic resistance of MRSA to various antibiotics.  Therefore, in order to prevent increased resistance to other antibiotics, it is recommended to avoid inappropriate use of antibiotics.


2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Mohammad Hossein Zamanian ◽  
Marya Shirvani ◽  
Alireza Janbakhsh ◽  
Babak Sayad ◽  
Siavash Vaziri ◽  
...  

Background: Staphylococcus aureus is an opportunistic pathogen, which often causes asymptomatic diseases. This bacterium could cause several disorders, ranging from skin infections to life-threatening diseases. S. aureus could also develop resistance to a wide range of antibiotics. Objectives: The present study aimed to investigate the prevalence and pattern of antibiotic resistance in isolated S. aureus in Imam Reza Hospital of Kermanshah, Iran. Methods: This descriptive cross-sectional study was conducted on 2,228 patients with a positive S. aureus culture who were admitted to Imam Reza Hospital during 2016 - 2018. In accordance with the CLSI protocol, bacterial isolates were separated using laboratory tests, and antibiotic susceptibility was assessed using the standard disk-diffusion method. Data analysis was performed in SPSS version 24. Results: Most of the S. aureus-positive cases were isolated from the emergency ward (43.7%), blood samples (40.1%), and urine samples (23.9%). The highest antibiotic resistance was observed against erythromycin, penicillin G, ofloxacin, cefoxitin, clindamycin, and piperacillin. With 93.3% and 81.8% sensitivity, vancomycin and teicoplanin were respectively the most effective antibiotics against S. aureus. Conclusions: According to the results, the prevalence of resistant S. aureus strains could be due to the long-term hospitalization of patients and the overuse of antibiotics in infection treatment. Therefore, proper monitoring and development of effective infection control methods are essential in these healthcare settings.


2021 ◽  
Vol 9 (3) ◽  
pp. 35-45
Author(s):  
Joseph Gbenga Solomon

A major concern in public health is Antibiotic resistance among pathogenic microorganisms. There are several organisms developing resistance to commonly used antibiotics in different locations and time. This study assessed patterns of antibiotic resistance in line with the WHO classification of antibiotics. A cross-sectional study was carried out from September 2020 to January 2021 in 4 randomly selected hospitals. Of all 442 patients recruited for this study, twenty-seven percent (122) were randomly selected for Antimicrobial Susceptibility Testing using the modified Kirby-Bauer disk diffusion method, and SPSS version 23 was used for analysis. The most predominant isolate was Staphylococcus aureus. Resistance by Staphylococcus aureus was noted against Amoxicillin, Trimethoprim-Sulfamethoxazole, Amoxicillin clavulanic acid, Gentamicin, and Cefuroxime. Resistance by E. coli against Chloramphenicol 80%, cefuroxime 100%, Trimethoprim-Sulfamethoxazole 83.3%, Resistance by Klebsiella spp; against Ampicillin Second and third-generation cephalosporin and Gentamicin 100%. Resistance by Streptococcus spp; Ampicillin 100% and Ampicillin cloxacillin 100%, cefuroxime 100%, and Ciprofloxacin 100%. Ciprofloxacin and levofloxacin were active against Salmonella species, Pseudomonas species, klebsiella, and Escherichia coli. Azithromycin, imipenem, and meropenem with high susceptibility to local bacterial isolates sample tested. The access group antibiotics showed a low susceptibility rate to local bacteria isolate with increase resistance to the watch group. Antibiogram was developed to guide empirical treatment type that is predominant in the district. Most bacteria isolated from health facilities in Kwara South were resistant to the access group. The resistance to watch a group of WHO antibiotics classification is building very fast. Keywords: Antibiotic Resistance, Empirical Treatment, Susceptible.


Author(s):  
Joanne Karzis ◽  
Inge-Marie Petzer ◽  
Edward F. Donkin ◽  
Vinny Naidoo

Antibiotic resistance of strains of Staphylococcus aureus isolated from bovine milk is of concern internationally. The objective of this study was to investigate trends of resistance of S. aureus to antibiotics administered to dairy cows in 19 South African and one Zambian dairy herds (participating in the South African proactive udder health management programme) and to identify possible contributing factors. The resistance of S. aureus strains to eight commonly used antibiotics in South Africa from 2001 to 2010 was evaluated. Staphylococcus aureus isolates (n = 2532) were selected from cows with subclinical mastitis in 20 herds routinely sampled as part of the proactive udder health management programme. The isolates were selected from milk samples that had somatic cell counts more than 400 000 cells/mL and were tested for antibiotic resistance using a standard Kirby–Bauer test with published clinical breakpoints. The prevalence of antibiotic resistance was evaluated as a percentage of S. aureus isolates susceptible out of the total numbers for each antibiotic selected per year. Staphylococcus aureus showed a significant increase in percentage of susceptible isolates over time for all antibiotics tested except for ampicillin. The overall prevalence of mastitis did not change during the study period. However, the prevalence of mastitis caused by S. aureus (mostly subclinical cases) in the selected herds decreased numerically but not significantly. Reduction in the incidence of antibiotic resistance shown by S. aureus was presumed to be a result of the application of the proactive udder health management programme. The fact that the overall prevalence of mastitis was kept stable was possibly because of the influence of the management programme in conjunction with the return of infections caused by non-resistant strains.


2021 ◽  
Vol 8 (4) ◽  
pp. 160-166
Author(s):  
Dominic Agbo Oche ◽  
Paul Ifeleke Oyegoke ◽  
Maryloveth Oluchukwu Akpudo ◽  
Busayo Olalekan Olayinka

Background and aims: Staphylococcus aureus, an important pathogen in bone diseases, is a highly multi-drug resistant (MDR) bacterium. This study aimed to investigate the antibiotic resistance among S. aureus isolated from patients on admission in an orthopaedic hospital. Methods: In this cross-sectional research, 140 samples comprising urine samples, wound swabs, and nasal swabs were collected from 49 patients on admission. Samples were cultured and screened for S. aureus following standard procedures. Using the agar-disk diffusion method, the isolates were subjected to antibiotics susceptibility tests. Results: S. aureus were isolated from 26 (18.6%) samples, and wound swabs were found to have the highest number of the S. aureus isolates with 12 (46.2%). Among the 26 S. aureus isolated, 25 (96.2%) isolates were resistant to at least four or more of the tested antibiotics. There were 23 (88.5%) MDR isolates, while there were only 2 (7.6%) extensively drug resistant ones. The number of methicillin-resistant S. aureus were 17 (65.4% of the isolates), while the number of methicillin-susceptible S. aureus were 9 (34.6% of the isolates). A total of 22 (84.6%) isolates had multi-antibiotic resistance (MAR) index greater than 0.2. Inducible clindamycin resistance of 2 (7.6%) was observed. Conclusion: This study showed that the S. aureus isolated from the patients were resistant to multiple antibiotics. Regular surveillance of antibiotic resistance is of utmost importance, since it facilitates the design or development of the treatment regimens that could check the spread of antimicrobial resistance.


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