Molecular characterization and detection of enterotoxins, methicillin resistance genes and antimicrobial resistance of Staphylococcus aureus from fish and ground beef

AbstractA total of 120 samples including 40 freshwaterfish(Oncorhynchus mykiss), 40 seawater fish (Sparus aurata) and 40 ground beef samples were examined for the presence of Staphylococcus aureus. The isolates were identified using biochemical tests and a PCR for the species-specific fragment (Sa442) and thermonuclease gene (nucA). The presence of staphylococcal enterotoxin genes (sea, seb, sec, sed and see), toxin genes (eta, etb, tsst), methicillin resistance gene (mecA) and some phenotypic virulence factors was also tested. Genotypic characterization of the isolates was analyzed by PCR-RFLP of the coa gene. Overall, 36 (30%) meat samples were contaminated with S. aureus. Of the 36 isolates, 3 (8.3%) were found to be positive for enterotoxin genes. Only 1 isolate (5.9%) from ground beef had the sea gene. In addition, 1 (12.5%) of the freshwater fish and 1 (9.1%) of the seawater fish carried both the sea and sed genes. The presence of seb, sec, see, eta, etb and tsst was not detected among the isolates of S. aureus. The amplified coa gene revealed five different clusters. Seven and six distinct RFLP patterns were obtained with AluI and HaeIII digestion, respectively. All isolates were found to be positive for slime, hemolytic and DNase activity while 41.7% of them were beta-lactamase positive. The presence of methicillin resistance was neither detected by PCR nor the disk diffusion method. A total of 94.4% of the isolates were resistant to at least one antimicrobial while 44.4% of them were resistant to at least two or more antimicrobials.

Download Full-text

Prevalence and antimicrobial drug resistance of Staphylococcus aureus isolated from cow milk samples

Veterinary World ◽

10.14202/vetworld.2020.2736-2742 ◽

2020 ◽

Vol 13 (12) ◽

pp. 2736-2742

Author(s):

Matlale Phriskey Mphahlele ◽

James Wabwire Oguttu ◽

Inge-Marie Petzer ◽

Daniel Nenene Qekwana

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Agents ◽

Methicillin Resistance ◽

Multidrug Resistant ◽

Cow Milk ◽

Diffusion Method ◽

Biochemical Tests ◽

Disk Diffusion Method ◽

Antimicrobial Drug Resistance ◽

Milk Samples

Background and Aim: Staphylococcus aureus infections and antimicrobial resistance (AMR) in mastitis cases are both of clinical and economic importance. This study investigated the prevalence and AMR patterns of S. aureus isolated from composite milk samples of dairy cows submitted to the Onderstepoort Milk Laboratory for routine diagnosis. Materials and Methods: A total of 2862 cow milk samples randomly selected from submitted samples were tested for the presence of S. aureus using microbiological and biochemical tests. Confirmation of isolates was done using the analytical profile index. Antimicrobial susceptibility of S. aureus isolates against 12 antimicrobial agents was determined using the disk diffusion method. Results: S. aureus was isolated from 1.7% (50/2862) of the samples tested. All (100%) S. aureus isolates were resistant to at least one antimicrobial, while 62% (31/50) were resistant to three or more categories of antimicrobials (multidrug-resistant [MDR]). Most S. aureus isolates were resistant to erythromycin (62%; 31/50) and ampicillin (62%; 31/50). Almost half of S. aureus isolates were resistant to oxacillin (46%; 23/50) and only 8% (4/50) were resistant to cefoxitin. Conclusion: Although the prevalence of S. aureus among mastitis cases in this study was low, isolates exhibited high resistance to aminoglycosides, macrolides, and penicillins, all of which are important drugs in human medicine. The high prevalence of MDR S. aureus and the presence of methicillin resistance among S. aureus observed in this study are of both clinical and public health concerns.

Download Full-text

Occurrence and characteristics of methicillin resistant Staphylococcus aureus and methicillin resistant coagulase-negative staphylococci in raw milk manufacturing

Czech Journal of Food Sciences ◽

10.17221/4443-cjfs ◽

2012 ◽

Vol 29 (Special Issue) ◽

pp. S11-S16 ◽

Cited By ~ 11

Author(s):

M. Vyletělová ◽

H. Vlková ◽

I. Manga

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Meca Gene ◽

Diffusion Method ◽

Biochemical Tests ◽

Coagulase Negative Staphylococci ◽

Disk Diffusion Method ◽

Methicillin Resistant ◽

Staphylococcal Cassette Chromosome

For monitoring the occurrence of MRSA (methicillin resistant Staphylococcus aureus) and MR-CNS (methicillin resistant coagulase-negative staphylococci), cow’s, goat’s, and sheep’s milks (bulk milks and individual samples) were investigated. Human nasal and throat swabs of the farm staff and nasal swabs of animals were also investigated as well. In total 1729 samples were examined and 634 strains were isolated by means of the cultivation method and used in this study. Generic identification of the staphylococci isolates was done performed by biochemical tests and all S. aureus and CNS isolates were checked by the PCR method for the presence of mecA gene which is responsible for methicillin resistance. The presence of the staphylococcal cassette chromosome mec (SCCmec), Panton-Valentine leukocidin (pvl) and genes encoding toxic shock syndrome toxin (tst) was detected in all strains confirmed as MRSA. The species were also examined for antimicrobial susceptibility by using disk diffusion method with antibiotic disks. S. aureus was the most frequently identified species from the samples tested (n = 557; 32.2%), followed by S. haemolyticus (n = 32; 1.9%), S. chromogenes (n = 24; 1.4%), S. epidermidis (n = 20; 1.2%), and S. caprae (n = 1; 0.16%). Among the resistant staphylococci (n = 49), S. aureus (n = 25; 51%) was found the most frequently, followed by S. epidermidis (n = 17; 34.7%), S. chromogenes (n = 6; 12.2%), and S. haemolyticus (n = 1; 2%). The resistant Staphyloccocus sp. occurred mainly in cow’s milk (MRSA, S. epidermidis, S. chromogenes, S. haemolyticus) and in animal’s swabs (S. epidermidis). One MRSA was also found in goat’s milk and one was isolated from human swab. No resistant strains were found in sheep’s milk. The negative results of the analysed genes presence (pvl, tst) were identical with all MRSA tested. The staphylococcal cassette chromosome mec (SCCmec) was classified as type IV or V.

Download Full-text

Methicillin-resistant Staphylococcus aureus bloodstream infection: risk factors and clinical outcome in non-intensive-care units

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/s0037-86822012000200010 ◽

2012 ◽

Vol 45 (2) ◽

pp. 189-193 ◽

Cited By ~ 4

Author(s):

Karinne Spirandelli Carvalho Naves ◽

Natália Vaz da Trindade ◽

Paulo Pinto Gontijo Filho

Keyword(s):

Risk Factors ◽

Staphylococcus Aureus ◽

Bloodstream Infection ◽

Antimicrobial Agents ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Diffusion Method ◽

Disk Diffusion Method ◽

Methicillin Resistant ◽

Staphylococcus Aureus Bloodstream Infection

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is spread out in hospitals across different regions of the world and is regarded as the major agent of nosocomial infections, causing infections such as skin and soft tissue pneumonia and sepsis. The aim of this study was to identify risk factors for methicillin-resistance in Staphylococcus aureus bloodstream infection (BSI) and the predictive factors for death. METHODS: A retrospective cohort of fifty-one patients presenting bacteraemia due to S. aureus between September 2006 and September 2008 was analysed. Staphylococcu aureus samples were obtained from blood cultures performed by clinical hospital microbiology laboratory from the Uberlândia Federal University. Methicillinresistance was determined by growth on oxacillin screen agar and antimicrobial susceptibility by means of the disk diffusion method. RESULTS: We found similar numbers of MRSA (56.8%) and methicillin-susceptible Staphylococcus aureus (MSSA) (43.2%) infections, and the overall hospital mortality ratio was 47%, predominantly in MRSA group (70.8% vs. 29.2%) (p=0.05). Age (p=0.02) was significantly higher in MRSA patients as also was the use of central venous catheter (p=0.02). The use of two or more antimicrobial agents (p=0.03) and the length of hospital stay prior to bacteraemia superior to seven days (p=0.006) were associated with mortality. High odds ratio value was observed in cardiopathy as comorbidity. CONCLUSIONS: Despite several risk factors associated with MRSA and MSSA infection, the use of two or more antimicrobial agents was the unique independent variable associated with mortality.

Download Full-text

Prevalence and Antibiograms of Salmonella in Commercially Produced Crocodile meat in Zimbabwe

Tanzania Veterinary Journal ◽

10.4314/tvj.v36i1.1 ◽

2021 ◽

Vol 36 (1) ◽

pp. 1-14

Author(s):

A.Z. Nhidza ◽

C. Gufe ◽

J. Marumure ◽

Z. Makuvara ◽

T. Chisango ◽

...

Keyword(s):

Hazard Analysis ◽

Control Point ◽

Penicillin G ◽

Diffusion Method ◽

Biochemical Tests ◽

Disk Diffusion Method ◽

Critical Control Point ◽

Meat Samples ◽

Low Prevalence ◽

Susceptibility Profiles

The presence of Salmonella in food products and emergence of antibiotic resistance are the major challenges facing public health policies. A total of 2749 crocodile meat samples obtained from the Central Veterinary Laboratories in Zimbabwe were screened for Salmonella specieswere collected from three Zimbabwean commercial farms between the year 2012 and 2019 for a retrospective observational study to determine the prevalence and magnitude of antibiotics resistant Salmonella species in crocodile meat. The isolation of Salmonella was in accordance with the ISO 6579:2002 and the antibiotic susceptibility testing was carried out based on Clinical and Laboratory Standard Institute’s recommendations by means of the Kirby-Bauer disk diffusion method. SILAB Database was used to determine the prevalence of Salmonella species. Prevalence was stratified by year and farms. Twenty Salmonella isolates were identified using biochemical tests, and 15 were confirmed by polymerase chain reaction (PCR). Antimicrobial susceptibility profiles of the confirmed Salmonella isolates were examined using 14 antibiotics. The overall prevalence of Salmonella species in crocodile meat samples was 0.5%. The prevalence of Salmonella species ranged from 0.04% to 0.44% in the crocodile meat samples and annual prevalence ranged from 0.01% to 1%. The highest prevalence of Salmonella (4.4%) was recorded in the year 2012. Salmonella isolates from one of the three tested farms were resistant to Erythromycin (73.33%), Ampicillin (80%), and Penicillin G (100%). Generally, Salmonella isolates displayed lower resistance to Cefepime, Ceftriaxone, Amikacin, Tetracycline, Ertapenem, Florfenicol, and Erythromycin (0-53.33%) whereas all Salmonella isolates showed susceptibility to Cefepime, Ceftriaxone, Ertapenem, and Florfenicol. Although the study indicates low prevalence of Salmonella species in crocodile meat, there is a need for strict implementation of Hazard Analysis Critical Control Point (HACCP) to reduce contamination rates in meat and its products

Download Full-text

Bacterial Etiology of Wound Exudates in Tertiary Care Cancer Patients and Antibiogram of the Isolates

Infectious Diseases Research and Treatment ◽

10.1177/1178633720952077 ◽

2020 ◽

Vol 13 ◽

pp. 117863372095207

Author(s):

Kiran Duwadi ◽

Sujan Khadka ◽

Sanjib Adhikari ◽

Sanjeep Sapkota ◽

Pabitra Shrestha

Keyword(s):

Staphylococcus Aureus ◽

Pathogenic Bacteria ◽

Methicillin Resistance ◽

Tertiary Care ◽

Antibiotic Sensitivity ◽

Cross Sectional Study ◽

Diffusion Method ◽

Disc Diffusion ◽

Biochemical Tests ◽

Cross Sectional

Introduction: Patients with malignancies frequently develop infections as a result of surgical procedures and fungating wounds leading to pus formation. This cross-sectional study was conducted to explore the bacteriological spectra of infections of various cancer sites and their antibiotic sensitivity patterns among the patients visiting minor operation theatre (OT) of B.P. Koirala Memorial Cancer Hospital (BPKMCH), Chitwan, Nepal. Methods: Over a period of 3 months from September to November 2018, a total of 183 wound exudates and pus samples were collected and analyzed by standard microbiological procedures. Isolates were identified based on the colony characters, Gram staining and an array of biochemical tests. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion technique according to criteria set by CLSI, 2016. Methicillin resistance in Staphylococcus aureus was tested with the help of cefoxitin using disc diffusion method. Results: Out of the 183 samples, 149 (81.4%) were culture positive. Among 13 different isolates identified, S. aureus (43.0%) was predominant followed by E. coli (14.0%). Higher incidence of bacteria was seen among the males (52.3%), in the age group 51 to 60 years (26.8%) and among the patients undergoing surgical intervention to deal with cancer (34.2%). The prevalence of wound infection was significantly affected by gender, age, and treatment regimen ( P < .01). Out of the total 68 S. aureus isolates, 38 (44.1%) were deemed as Methicillin-resistant Staphylococcus aureus (MRSA). Among the 158 isolates, 85 (53.8%) were multi-drug resistant (MDR). Cefepime was the most effective antibiotic for Gram positive isolates whereas both imipenem and meropenem were found to be equally more effective for Gram negative isolates. Conclusion: This study suggests that patients with malignancies harbor pathogenic bacteria; therefore, prudent use of antibiotics is essential to prevent the emergence of MDR pathogens.

Download Full-text

Characterization of SCCmec, spa types and Multi Drug Resistant of methicillin-resistant Staphylococcus aureus isolates among inpatients and outpatients in a referral hospital in Shiraz, Iran

BMC Research Notes ◽

10.1186/s13104-019-4627-z ◽

2019 ◽

Vol 12 (1) ◽

Cited By ~ 4

Author(s):

Zahra Hashemizadeh ◽

Nahal Hadi ◽

Samane Mohebi ◽

Davood Kalantar-Neyestanaki ◽

Abdollah Bazargani

Keyword(s):

Staphylococcus Aureus ◽

Diffusion Method ◽

Biochemical Tests ◽

Spa Typing ◽

Disk Diffusion Method ◽

Methicillin Resistant ◽

Tertiary Hospitals ◽

Antimicrobial Susceptibility Tests ◽

Susceptibility Tests ◽

Spa Types

Abstract Objectives Molecular typing such as spa typing is used to control and prevent Staphylococcus aureus widespread in hospitals and communities. Hence, the aim of this study was to find the most common types of S. aureus strain circulating in Shiraz via spa and SCCmec typing methods. Results Total of 159 S. aureus isolates were collected from two tertiary hospitals in Shiraz. Isolates were identified by biochemical tests. Antimicrobial susceptibility tests were performed by standard disk diffusion method and then genetic analysis of bacteria was performed using SCCmec and spa typing. In this study 31.4% of the isolates were methicillin-resistant S. aureus. The majority of isolates were SSCmec type III. Spa type t030 was the most prominent type among MRSA strains. For the first time in Iran, spa003, t386, t1877, t314, t186, t1816, t304, t325, t345 were reported in this study. It was shown that there is a possibility that these spa types are native to this region. Our findings showed that SCCmec II, III and IV disseminate from hospital to community and vice versa. Thus, effective monitoring of MRSA in hospital and community is necessary.

Download Full-text

Correlation between mazEF Toxin-Antitoxin System Expression and Methicillin Susceptibility in Staphylococcus aureus and Its Relation to Biofilm-Formation

Microorganisms ◽

10.3390/microorganisms9112274 ◽

2021 ◽

Vol 9 (11) ◽

pp. 2274

Author(s):

Aya Abd El rahman ◽

Yasmine El kholy ◽

Rania Y. Shash

Keyword(s):

Staphylococcus Aureus ◽

Biofilm Formation ◽

Methicillin Resistance ◽

Diffusion Method ◽

P Value ◽

Sequence Motifs ◽

University Hospitals ◽

Specific Sequence ◽

Disk Diffusion Method ◽

Cellular Mrnas

Methicillin resistance in Staphylococcus aureus has become prevalent globally. Moreover, biofilm-formation makes it more difficult to eradicate bacteria by antibiotics. The mazEF toxin-antitoxin system encodes for mazF, which acts as an endoribonuclease that cleaves cellular mRNAs at specific sequence motifs (ACA), and mazE, which opposes the mazF action. Our goal was to detect mazEF expression in methicillin-resistant S. aureus (MRSA) isolates compared with methicillin-sensitive S. aureus (MSSA) isolates and determine its relation to methicillin susceptibility as well as biofilm-formation. According to their susceptibility to cefoxitin disks, 100 S. aureus isolates obtained from patients admitted to Cairo University Hospitals were categorized into 50 MSSA and 50 MRSA according to their susceptibility to cefoxitin disks (30 µg). Antimicrobial susceptibility and biofilm-formation were investigated using the disk diffusion method and tissue culture plate method, respectively. Finally, using real-time PCR, mazEF expression was estimated and correlated to methicillin susceptibility and biofilm formation. Both MRSA and MSSA isolates showed the best sensitivity results with linezolid and gentamicin, where about 88% of MRSA isolates and 96% of MSSA isolates were sensitive to linezolid while 76% of MRSA isolates and 84% of MSSA isolates were sensitive to gentamicin. MRSA isolates were significantly more able to form biofilm than MSSA isolates (p-value = 0.037). The mazEF expression was significantly correlated to methicillin resistance in S. aureus (p-value < 0.001), but not to biofilm-formation.

Download Full-text

Characterization of SCCmec, spa types and Multi Drug Resistant of meticillin-resistant Staphylococcus aureus isolates among inpatients and outpatients in a referral hospital in Shiraz, Iran.

10.21203/rs.2.10702/v2 ◽

2019 ◽

Author(s):

zahra hashemizadeh ◽

nahal hadi ◽

samane mohebi ◽

davood kalantar-Neyestanaki ◽

abdolla bazargani

Keyword(s):

Staphylococcus Aureus ◽

Diffusion Method ◽

Biochemical Tests ◽

Spa Typing ◽

Disk Diffusion Method ◽

Methicillin Resistant ◽

Sccmec Typing ◽

Tertiary Hospitals ◽

Antimicrobial Susceptibility Tests ◽

Spa Types

Abstract Objectives: Molecular typing such as spa typing is used to control and prevent of Staphylococcus. aureus widespread in hospitals and community acquired. Hence, the aim of this study was to find the common types of S. aureus strains circulating in Shiraz via spa and SCCmec typing methods. Results: Total of 159 S. aureus isolates were collected from two tertiary hospitals in Shiraz. Isolates were identified by biochemical tests. Antimicrobial susceptibility tests were performed by standard disk diffusion method and then genetic analysis of bacteria was performed using SCCmec and spa typing. In this study 31.4% of the isolates were methicillin-resistant S. aureus. The majority of isolates were SSC mec type ІІІ. Spa type t030 was the most prominent type among MRSA strains. In this study, for the first time in Iran, spa003, t386, t1877, t314, t186, t1816, t304, t325, t345 were reported. It was shown that there is a possibility that these spa types are natives to this region. Our findings showed that SCCmec ІІ, ІІІ and IV disseminate from hospital to community and vice versa. Thus, effective monitoring of MRSA in hospital and community is desirable. Keyword: Staphylococcus aureus , methicillin-resistant S. aureus (MRSA), SCCmec typing, spa typing

Download Full-text