scholarly journals Molecular typing, phenotypic and genotypic assessment of antibiotic resistance and virulence factors amongst the Staphylococcus aureus bacteria isolated from raw chicken meat

2020 ◽  
Author(s):  
Nazanin Fazel ◽  
Sepideh Karimi ◽  
Hassan Momtaz

Abstract Background: Staphylococcus aureus is an important cause of foodborne diseases due to the consumption of contaminated raw chicken meat. The present research was performed to evaluate the phenotypic and genotypic properties of antibiotic resistance, virulence factor profiles and molecular typing of S. aureus strains isolated from chicken meat. A total of 36 S. aureus strains were isolated from raw chicken meat samples. Phenotypic pattern of antibiotic resistance was assessed by disk diffusion. Distribution of antibiotic resistance and virulence genes was evaluated by PCR. Molecular typing of isolates was perform ed by the ERIC-PCR. Results: Considering the over than 80% similarity, 36 S. aureus isolates were classified in 9 different profiles with 43 to 100% similarities. S. aureus strains showed the highest incidence of resistance against penicillin (100%), tetracycline (91.66%), cephalothin (77.77%), ciprofloxacin (75%), erythromycin (75%), mupirocin (63.88%), clindamycin (61.11%) and trimethoprim/sulfamethoxazole (61.11%). The most commonly detected antibiotic resistance genes amid the S. aureus isolates were mecA (100%), tetK (80.55%), tetM (66.66%), aacA-D (61.11%), msrA (55.55%) and ermA (55.55%). Total distribution of etB, etA, tsst-1, clfA and coa virulence factors amongst the S. aureus strains was 61.11%, 58.33%, 13.88%, 75% and 100%, respectively. Conclusions: Genetic cluster of bacteria affected the antibiotic resistance and virulence characters of S. aureus strains. S. aureus strains with the same ERIC-genetic cluster had similar antibiotic resistance and virulence characters which may show their similar origins. Presence of one or more virulence factors and antibiotic resistance genes amongst the resistant-S. aureus strains signifies an important public health threat rendering the consumption of raw or undercooked chicken meat.

2020 ◽  
Author(s):  
Bahareh Tavakoli-Far ◽  
Bita Mousavi ◽  
Zohreh Mashak ◽  
Mohammad Adel Rezaei ◽  
Fatemeh Doregiraee ◽  
...  

Abstract BackgroundMethicillin-resistant Staphylococcus aureus is an important cause of foodborne diseases. The present research evaluated the antibiotic resistance properties, distribution of virulence factors, and molecular typing of MRSA bacteria isolated from vegetable and salad samples. MethodsThree-hundred and fifty vegetable and salad samples were examined for the presence of S. aureus using the culture. MRSA bacteria were identified using cefoxitin and oxacillin disk diffusion. The phenotypic pattern of antibiotic resistance was assessed by disk diffusion. ResultsThe PCR evaluated the distribution of antibiotic resistance and virulence genes. Forty-five out of 350 (12.85%) vegetable and salad samples were positive for S. aureus. Twenty-six isolates out of 45 (57.77%) S. aureus bacteria were determined as MRSA. MRSA bacteria harbored the uppermost prevalence of resistance against cefoxitin (100%), ceftaroline (100%), penicillin (100%), tetracycline (88.46%), gentamicin (80.76%), trimethoprim-sulfamethoxazole (69.23%), and erythromycin (69.23%). The prevalence of MRSA bacteria resistance recovered from vegetable and salad samples against more than seven antibiotic agents was 12.50% and 27.77%, respectively. BlaCTX-M (100%), blaZ (100%), aacA-D (61.53%), tetK (57.69%), dfrA1 (46.15%), and vanA (42.30%) were the most commonly detected antibiotic resistance genes. PVL (57.69%), coa (53.84%), and hla (38.46%) were the most commonly detected virulence factors amongst the MRSA bacteria. ConclusionMRSA isolates had a similarity lower than 80%, categorized in the same group. The presence of one or more virulence factors and antibiotic resistance genes amongst the resistant-MRSA bacteria signifies an important threat rendering the consumption of contaminated vegetables and salads.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Xuehan Li ◽  
Tao Huang ◽  
Kai Xu ◽  
Chenglin Li ◽  
Yirong Li

Abstract Background There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus (S. aureus) from Hainan, the southernmost province of China. Methods Two hundred twenty-seven S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013–2014 and 2018–2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. Results Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A (spa) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013 to 2014 (5.5%, 5/91) to 2018–2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCCmec) typing. SCCmec-IVa was the predominant SCCmec type, and specifically, ST45-SCCmec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S. aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin (pvl) and eta, were determined, and the frequency of eta and pvl were found to be 57.3 and 47.6%. Such high prevalence has never been seen in mainland China before. Conclusion S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.


2020 ◽  
Author(s):  
Raymond Mudzana ◽  
Rooyen T Mavenyengwa ◽  
Muchaneta Gudza-Mugabe

Abstract Background: Streptococcus agalacticae is one of the most important causative agents of serious infections among neonates. Group B Streptococcus (GBS) virulence factors are important in the development of vaccines, whilst antibiotic resistance genes are necessary in understanding the resistance mechanisms used by these pathogens. This study was carried out to identify the virulence genes and antibiotic resistance genes associated with GBS isolated from pregnant women.Methods: A total of 43 GBS isolates were obtained from vaginal samples that were collected from all HIV positive and HIV negative women who were 13-35 weeks pregnant attending Antenatal Care at both Chitungwiza and Harare Central Hospitals in Zimbabwe. Identification tests of GBS isolates was done using standard bacteriological methods including molecular tests. Antibiotic susceptibility testing using 3 antibiotics was done using the modified Kirby-Bauer method. The boiling method was used to extract DNA and Polymerase Chain Reaction (PCR) was used to screen for 13 genes in the isolates. Data was fed into SPSS 24.0 and the Spearman rank correlation test used to determine any correlation among genes.Results: Nine distinct virulence gene profiles were identified. The profiles hly-scpB-bca-rib 37.2% (16/43) and hly-scpB-bca 18.6% (8/43) were common among GBS isolates. The following virulence gene frequencies were obtained namely hly 97.8% (42/43), scpB 90.1% (39/43), bca 86.0% (37/43), rib 69.8% (30/43) and bac 11.6% (5/43). Antibiotic resistance genes showed high frequencies for tetM 97.6% (41/42) and low frequencies for ermB 34.5% (10/29), ermTR 10.3% (3/29), mefA 3.4% (1/29), tetO 2.4% (1/42) and linB 0% (0/35). The atr housekeeping gene amplification yielded 100% (43/43) positive results, whilst the mobile genetic element IS1548 yielded a low 9.3% (4/43).Conclusion: The study showed a high prevalence of multiple virulence genes hly, scpB, bca and rib in S. agalactiae strains isolated from pregnant women. Tetracycline resistance was found to be predominantly caused by the tetM gene, whilst macrolide resistance was predominantly due to the presence of erm methylase, with the ermB gene being more prevalent. It was also observed that in vitro phenotypic resistance is not always accurately predicted by resistance genotypes.


2019 ◽  
Author(s):  
Xuehan Li ◽  
Tao Huang ◽  
Kai Xu ◽  
Chenglin Li ◽  
Yirong Li

Abstract Background: There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus ( S. aureus ) from Hainan, the southernmost province of China. Methods: 227 S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013-2014 and 2018-2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. Results: Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A ( spa ) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013-2014 (5.5%, 5/91) to 2018-2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCC mec ) typing. SCC mec- IVa was the predominant SCC mec type, and specifically, ST45-SCC mec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S . aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin ( pvl ) and eta , were determined, and the frequency of eta and pvl were found to be 57.3% and 47.6%. Such high prevalence has never been seen in mainland China before. Conclusion: S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.


2019 ◽  
Author(s):  
Xuehan Li ◽  
Tao Huang ◽  
Kai Xu ◽  
Chenglin Li ◽  
Yirong Li

Abstract Background: There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus ( S. aureus ) from Hainan, the southernmost province of China. Methods: 227 S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013-2014 and 2018-2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. Results: Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A ( spa ) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013-2014 (5.5%, 5/91) to 2018-2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCC mec ) typing. SCC mec- IVa was the predominant SCC mec type, and specifically, ST45-SCC mec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S . aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin ( pvl ) and eta , were determined, and the frequency of eta and pvl were found to be 57.3% and 47.6%. Such high prevalence has never been seen in mainland China before. Conclusion: S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S904-S904
Author(s):  
Edward W Adams ◽  
Doyle V Ward ◽  
Bruce A Barton ◽  
Richard T Ellison ◽  
Oladapo Olaitan

Abstract Background Although multiple different virulence factors have been identified for Staphylococcus aureus, there is limited information on genetic variation present between different strains of S. aureus in the clinical setting. To better define whether differing virulence factors could contribute to differing clinical manifestations of S. aureus infections we undertook a comparison of the frequency of virulence and antibiotic resistance genes present in S. aureus isolates from different clinical sites. Methods Whole-genome sequencing was performed on a convenience sample of S. aureus isolates from clinical or surveillance cultures obtained at an academic medical center over a 27-month period. Genomic assemblies were generated and annotated to define protein-coding regions. The prevalence of 28 genes previously defined as being associated with S. aureus virulence or antimicrobial resistance, including MSCRAMM genes, was then analyzed in relation to nine specific culture sources including only a single isolate from each culture source per patient using a likelihood ratio χ 2 analysis. Results There were 1286 S. aureus isolates with draft assemblies and annotations, and there was a statistically significant (P < 0.01) difference in gene frequencies between culture sources for 18 genes that included 13 of 19 virulence factors, 4 of 7 antibiotic resistance genes and 1 of 2 MSCRAMM genes. The most notable variation was seen for the presence of the sec, sep, entB, lukS, lufK, fosB, mecA, and ermA genes (all with P < 0.0001). There were also significant variations in overall gene frequency patterns between isolates from wound, blood, and respiratory isolates (P < 0.0001), as well as significant differences in the frequency of cna and hlY genes between surveillance and clinical isolates (P < 0.0001). Conclusion This study demonstrates a difference in the prevalence of virulence and antibiotic resistance genes in S. aureus isolates based on the culture source. As the culture location can be considered a surrogate for different types of infections (such as bacteremia, pneumonia, urinary tract infections) these differences in gene frequency may contribute to variation in the clinical manifestations of infections by differing S. aureus strains. Disclosures All authors: No reported disclosures.


2020 ◽  
Author(s):  
Raymond Mudzana ◽  
Rooyen T Mavenyengwa ◽  
Muchaneta Gudza-Mugabe

Abstract Background : Streptococcus agalacticae (Group B Streptococcus, GBS) is one of the most important causative agents of serious infections among neonates. GBS virulence factors are important in vaccine development, whilst antibiotic resistance genes are necessary in understanding the resistance mechanisms used by pathogens. This study was carried out to identify virulence genes and antibiotic resistance genes associated with GBS isolated from pregnant women. Methods: A total of 43 GBS isolates were obtained from 420 vaginal samples collected from HIV positive and negative women who were 13-35 weeks pregnant attending Antenatal Care at Chitungwiza and Harare Central Hospitals in Zimbabwe. Identification tests of GBS isolates was done using standard bacteriological methods including molecular tests. Antibiotic susceptibility testing using 3 antibiotics was done using the modified Kirby-Bauer method. The boiling method was used to extract DNA and Polymerase Chain Reaction (PCR) was used to screen for 13 genes. Data was fed into SPSS 24.0 and the Spearman rank correlation test used to determine correlation among genes. Results: Nine distinct virulence gene profiles were identified. The profiles hly-scpB-bca-rib 37.2% (16/43) and hly-scpB-bca 18.6% (8/43) were common. The following virulence gene frequencies were obtained namely hly 97.8% (42/43), scpB 90.1% (39/43), bca 86.0% (37/43), rib 69.8% (30/43) and bac 11.6% (5/43). High resistance to tetracycline 97.7% (42/43) was reported followed by clindamycin 55.8% (24/43) and erythromycin 30.2% (13/43). Antibiotic resistance genes among the resistant and intermediate-resistant isolates showed high frequencies for tetM 97.6% (41/42) and low frequencies for ermB 34.5% (10/29), ermTR 10.3% (3/29), mefA 3.4% (1/29), tetO 2.4% (1/42) and linB 0% (0/35). The atr housekeeping gene yielded 100% (43/43) positive results, whilst the mobile genetic element IS1548 yielded 9.3% (4/43). Conclusion: The study showed high prevalence of multiple virulence genes hly, scpB, bca and rib in S. agalactiae strains isolated from pregnant women. Tetracycline resistance was found to be predominantly caused by the tetM gene, whilst macrolide resistance was predominantly due to the presence of erm methylase, with the ermB gene being more prevalent. It was also observed that in vitro phenotypic resistance is not always accurately predicted by resistance genotypes.


2019 ◽  
Author(s):  
Xuehan Li ◽  
Tao Huang ◽  
Kai Xu ◽  
Chenglin Li ◽  
Yirong Li

Abstract Background: There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus ( S. aureus ) from Hainan, the southernmost province of China. Methods: 227 S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013-2014 and 2018-2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. Results: Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A ( spa ) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013-2014 (5.5%, 5/91) to 2018-2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCC mec ) typing. SCC mec- IVa was the predominant SCC mec type, and specifically, ST45-SCC mec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S . aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin ( pvl ) and eta , were determined, and the frequency of eta and pvl were found to be 57.3% and 47.6%. Such high prevalence has never been seen in mainland China before. Conclusion: S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.


2020 ◽  
Author(s):  
Roya Chabi

Abstract Methicillin-resistant Staphylococcus aureus (MRSA) is considered to be one of the most important causes of food-borne diseases. The present investigation was done to assess the phenotypic and genotypic characterization and distribution of Staphylococcal cassette chromosome mec types and Panton–Valentine leukocidin gene in the MRSA strains isolated from raw meat samples. Six-hundred and eighty meat samples were collected and cultured. MRSA strains were subjected to disk diffusion and Polymerase Chain Reaction. One-hundred and thirty-five out of 680 (18.38%) raw meat samples were positive for S. aureus. Seventy-nine out of 125 (63.20%) S. aureus strains were determined as MRSA. Raw sheep meat samples (75%) had the highest prevalence of MRSA, while raw camel had the lowest (50%). Fifty-eight out of 79 (73.41%) MRSA strains harbored the PVL gene. SCCmec IVa (39.65%), V (22.41%) and III (10.34%) were the most commonly detected types in the MRSA strains. MRSA strains harbored the highest prevalence of resistance against penicillin (100%), tetracycline (100%), gentamicin (65.51%) and erythromycin (56.89%). AadA1 (58.62%), tetK (56.89%), msrA (41.37%) and vatA (36.20%) were the most commonly detected antibiotic resistance genes. Simultaneous presence of PVL and antibiotic resistance genes in multi-drug resistant MRSA strains specifies significant public health problem.


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