scholarly journals Virulence factors and antibiotic resistance properties of the Staphylococcus epidermidis strains isolated from hospital infections in Ahvaz, Iran

2019 ◽  
Vol 47 (1) ◽  
Author(s):  
Roya Chabi ◽  
Hassan Momtaz

Abstract Background Resistant Staphylococcus epidermidis strains are considered to be one of the major causes of human clinical infections in hospitals. The present investigation was done to study the pattern of antibiotic resistance and the prevalence of virulence and antibiotic resistance genes amongst the S. epidermidis strains isolated from human hospital infections. Methods One hundred hospital infectious samples were collected and S. epidermidis strains were identified using culture and biochemical tests. Isolated strains were subjected to disk diffusion and PCR. Results Forty-six out of 100 hospital infectious samples (46%) were positive for S. epidermidis. S. epidermidis strains harbored the highest prevalence of resistance against penicillin (95.65%), tetracycline (91.30%), erythromycin (82.60%), cefazolin (78.26%), and trimethoprim-sulfamethoxazole (73.91%). All S. epidermidis strains had resistance against at least three different types of antibiotics, while the prevalence of resistance against more than seven types of antibiotics was 17.39%. AacA-D (69.56%), tetK (56.52%), mecA (45.65%), msrA (39.13%), and tetM (39.13%) were most commonly detected antibiotic resistance genes. The prevalence of vatC (4.34%), ermA (8.69%), vatA (8.69%), vatB (13.04%), ermC (13.04%), and linA (10.86%) were lower than other detected antibiotic resistance genes. ClfA (32.60%), agrIII (17.39%), and etB (13.04%) were the most commonly detected virulence factors. Conclusions The presence of virulent and multi-drug resistance S. epidermidis strains showed an important public health issue in hospitals.

2020 ◽  
Author(s):  
Mohammad Chehelgerdi ◽  
Reza Ranjbar

Abstract Background The present investigation aimed to assess the antibiotic resistance properties and distribution of virulence factors in the Streptococcus spp. isolated from hospital cockroaches. Methods Six-hundred and sixty cockroach samples were collected. Cockroaches were vigorously washed with normal saline, and the achieved saline was used for bacterial culture. Isolated Streptococcus spp. were subjected to disk diffusion as well as PCR amplification of virulence factors and antibiotic resistance genes. Results Prevalence of S. pyogenes, S. agalactiae and S. pneumonia was 4.82%, 1.66% and 6.96%, respectively. The highest prevalence of S. pyogenes, S. agalactiae and S. pneumonia were found in oriental (5.71%), oriental (2.85%) and American (7.71%) cockroaches, respectively. Cfb (53.93%), cyl (52.8%), scaa (51.68%) and glna (50.56%) were the most commonly detected streptococcal virulence factors. Pbp2b (71.91%), pbp2 × (58.42%), mefA (46.06%), ermB (46.06%) and tetM (46.06%) were the most commonly detected antibiotic resistance genes. Streptococcal spp. exhibited the highest prevalence of resistance against tetracycline (80.89%), trimethoprim (65.16%), and penicillin (56.17%). Conclusion To the best of our knowledge, this is the first prevalence report of virulence factors and antibiotic resistance genes in the Streptococcal spp. isolated from American, German and oriental hospital cockroaches. Findings recommended a certain role for cockroaches in the transmission of nosocomial infections and particularly those caused by virulent and resistant Streptococcus spp. in the hospital environment.


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.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 170
Author(s):  
Angela França ◽  
Vânia Gaio ◽  
Nathalie Lopes ◽  
Luís D. R. Melo

Coagulase-negative staphylococci (CoNS) have emerged as major pathogens in healthcare-associated facilities, being S. epidermidis, S. haemolyticus and, more recently, S. lugdunensis, the most clinically relevant species. Despite being less virulent than the well-studied pathogen S. aureus, the number of CoNS strains sequenced is constantly increasing and, with that, the number of virulence factors identified in those strains. In this regard, biofilm formation is considered the most important. Besides virulence factors, the presence of several antibiotic-resistance genes identified in CoNS is worrisome and makes treatment very challenging. In this review, we analyzed the different aspects involved in CoNS virulence and their impact on health and food.


Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1313
Author(s):  
Ning Zhang ◽  
Xiang Liu ◽  
Bing Li ◽  
Limei Han ◽  
Xuejiao Ma ◽  
...  

Antibiotic resistance is currently a major global public health issue. In particular, the emergence and transfer of antibiotic resistance genes (ARGs) is a matter of primary concern. This study presented a method for ruling out the transfer of naked DNA (plasmid RP4 lysed from donor cells) during the cell-to-cell conjugation, using a modified “U-tube”. A series of gene transfer assays was conducted in both flask and modified U-tube, using Pseudomonas putida KT2440 (P. putida (RP4)) harboring the RP4 plasmid as the donor strain, Escherichia coli (E. coli, ATCC 25922) in pure culture as sole recipient, and bacteria from reclaimed water microcosms as multi-recipients. The verification experiments showed that the U-tube device could prevent direct contact of bacteria without affecting the exchange of free plasmid. In the experiments involving a sole recipient, the transconjugants were obtained in flask samples, but not in modified U-tube. Furthermore, in experiments involving multi-recipients, transfer of naked DNA in the modified U-tube accounted for 5.18% in the transfer frequency of the flask transfer experiment. The modified U-tube proved to be useful for monitoring the interference of naked DNA in the research of conjugative transfer and calculating the exact conjugative transfer rate. This device is identified as a promising candidate for distinguishing different gene transfers in practical application because of its convenient use and easy and simple manufacture.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abdelazeem M. Algammal ◽  
Mahmoud Mabrok ◽  
Elayaraja Sivaramasamy ◽  
Fatma M. Youssef ◽  
Mona H. Atwa ◽  
...  

Abstract This study aimed to investigate the prevalence, antibiogram of Pseudomonasaeruginosa (P.aeruginosa), and the distribution of virulence genes (oprL,exoS, phzM, and toxA) and the antibiotic-resistance genes (blaTEM, tetA, and blaCTX-M). A total of 285 fish (165 Oreochromisniloticus and 120 Clariasgariepinus) were collected randomly from private fish farms in Ismailia Governorate, Egypt. The collected specimens were examined bacteriologically. P. aeruginosa was isolated from 90 examined fish (31.57%), and the liver was the most prominent infected organ. The antibiogram of the isolated strains was determined using a disc diffusion method, where the tested strains exhibited multi-drug resistance (MDR) to amoxicillin, cefotaxime, tetracycline, and gentamicin. The PCR results revealed that all the examined strains harbored (oprL and toxA) virulence genes, while only 22.2% were positive for the phzM gene. On the contrary, none of the tested strains were positive for the exoS gene. Concerning the distribution of the antibiotic resistance genes, the examined strains harbored blaTEM, blaCTX-M, and tetA genes with a total prevalence of 83.3%, 77.7%, and 75.6%, respectively. Experimentally infected fish with P.aeruginosa displayed high mortalities in direct proportion to the encoded virulence genes and showed similar signs of septicemia found in the naturally infected one. In conclusion, P.aeruginosa is a major pathogen of O.niloticus and C.gariepinus.oprL and toxA genes are the most predominant virulence genes associated with P.aeruginosa infection. The blaCTX-M,blaTEM, and tetA genes are the main antibiotic-resistance genes that induce resistance patterns to cefotaxime, amoxicillin, and tetracycline, highlighting MDR P.aeruginosa strains of potential public health concern.


mSystems ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Yu Pan ◽  
Jiaxiong Zeng ◽  
Liguan Li ◽  
Jintao Yang ◽  
Ziyun Tang ◽  
...  

ABSTRACT Widespread use of antibiotics has enhanced the evolution of highly resilient pathogens and poses a severe risk to human health via coselection of antibiotic resistance genes (ARGs) and virulence factors (VFs). In this study, we rigorously evaluate the abundance relationship and physical linkage between ARGs and VFs by performing a comprehensive analysis of 9,070 bacterial genomes isolated from multiple species and hosts. The coexistence of ARGs and VFs was observed in bacteria across distinct phyla, pathogenicities, and habitats, especially among human-associated pathogens. The coexistence patterns of gene elements in different habitats and pathogenicity groups were similar, presumably due to frequent gene transfer. A shorter intergenic distance between mobile genetic elements and ARGs/VFs was detected in human/animal-associated bacteria, indicating a higher transfer potential. Increased accumulation of exogenous ARGs/VFs in human pathogens highlights the importance of gene acquisition in the evolution of human commensal bacteria. Overall, the findings provide insights into the genic features of combinations of ARG-VF and expand our understanding of ARG-VF coexistence in bacteria. IMPORTANCE Antibiotic resistance has become a serious global health concern. Despite numerous case studies, a comprehensive analysis of ARG and VF coexistence in bacteria is lacking. In this study, we explore the coexistence profiles of ARGs and VFs in diverse categories of bacteria by using a high-resolution bioinformatics approach. We also provide compelling evidence of unique ARG-VF gene pairs coexisting in specific bacterial genomes and reveal the potential risk associated with the coexistence of ARGs and VFs in organisms in both clinical settings and environments.


2007 ◽  
Vol 35 (Database) ◽  
pp. D391-D394 ◽  
Author(s):  
C. E. Zhou ◽  
J. Smith ◽  
M. Lam ◽  
A. Zemla ◽  
M. D. Dyer ◽  
...  

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
M. B. Couger ◽  
Anna Wright ◽  
Erika I. Lutter ◽  
Noha Youssef

We report here the draft genome sequences of five Pseudomonas aeruginosa isolates obtained from sputum samples from two cystic fibrosis patients with chronic colonization. These closely related strains harbor 225 to 493 genes absent from the P. aeruginosa POA1 genome and contain 178 to 179 virulence factors and 29 to 31 antibiotic resistance genes.


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. This study was carried out to identify antibiotic resistance and virulence 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 and molecular identification testing. Antibiotic susceptibility testing was done using the modified Kirby-Bauer method and E-test strips. 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.Results: Nine distinct virulence gene profiles were identified and hly-scpB-bca-rib 37.2% (16/43) was common. The virulence genes identified were 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 72.1% (31/43) cefazolin, 69.8% (30/43) penicillin G, 58.1% (25/43) ampicillin, 55.8% (24/43) clindamycin, 46.5% (20/43) ceftriaxone, 34.9% (15/43) chloramphenicol, and 30.2% (13/43) for both erythromycin and vancomycin using disk diffusion. 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 hly, scpB, bca and rib virulence genes in S. agalactiae strains isolated from pregnant women. Tetracycline resistance was 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. Multi-drug resistance coupled with the recovery of resistant isolates to antimicrobial agents such as penicillins indicates the importance of GBS surveillance and susceptibility tests. It was also observed that in vitro phenotypic resistance is not always accurately predicted by resistance genotypes.


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