scholarly journals An overview: the virulence capacity, resistance mechanism, integron association, biofilm formation ability, and methicillin- resistance traits among staphylococcus aureus

2020 ◽  
Vol 11 (2) ◽  
pp. 23-41
Author(s):  
Anas Almousawi ◽  
Abdullah Alhatami ◽  
Furkan Alaraji
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Methicillin Resistance ◽  
Meca Gene ◽  
Resistance Mechanism ◽  
Health Institutions ◽  
Animal Communities ◽  
Resistance Traits

The ability of Staphylococcus aureus (S. aureus) to acquire variety and many virulence genes that leads to its the ability to cause different diseases in many hosts species, these bacteria have many mechanisms for antibiotic resistance and their ability to produce biofilm and gain various genes through integrons, that will lead to difficult treatment. Consequently, the acquisition of the mecA gene made it more virulent and resistant to antibiotics, and this indicates that the spread of these bacteria in human and animal communities besides health institutions and their frequent transmission between these communities may have a problem of dealing with it.

scholarly journals Mutation-Based Antibiotic Resistance Mechanism in Methicillin-Resistant Staphylococcus aureus Clinical Isolates

2021 ◽  
Vol 14 (5) ◽  
pp. 420
Author(s):  
Tanveer Ali ◽  
Abdul Basit ◽  
Asad Mustafa Karim ◽  
Jung-Hun Lee ◽  
Jeong-Ho Jeon ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Active Site ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Resistance Mechanism ◽  
Ligand Docking ◽  
Clinical Samples ◽  
Allosteric Site ◽  
Methicillin Resistant

β-Lactam antibiotics target penicillin-binding proteins and inhibit the synthesis of peptidoglycan, a crucial step in cell wall biosynthesis. Staphylococcus aureus acquires resistance against β-lactam antibiotics by producing a penicillin-binding protein 2a (PBP2a), encoded by the mecA gene. PBP2a participates in peptidoglycan biosynthesis and exhibits a poor affinity towards β-lactam antibiotics. The current study was performed to determine the diversity and the role of missense mutations of PBP2a in the antibiotic resistance mechanism. The methicillin-resistant Staphylococcus aureus (MRSA) isolates from clinical samples were identified using phenotypic and genotypic techniques. The highest frequency (60%, 18 out of 30) of MRSA was observed in wound specimens. Sequence variation analysis of the mecA gene showed four amino acid substitutions (i.e., E239K, E239R, G246E, and E447K). The E239R mutation was found to be novel. The protein-ligand docking results showed that the E239R mutation in the allosteric site of PBP2a induces conformational changes in the active site and, thus, hinders its interaction with cefoxitin. Therefore, the present report indicates that mutation in the allosteric site of PBP2a provides a more closed active site conformation than wide-type PBP2a and then causes the high-level resistance to cefoxitin.

scholarly journals Isolation of Biofilm Producing Methicillin-Resistant Staphylococcus aureus from Hospitalized Orthopaedic Patients in Kano State, Nigeria

2021 ◽  
Vol 28 (1) ◽  
pp. 66-74
Author(s):  
D.A. Oche ◽  
U. Abdulrahim ◽  
A.S. Oheagbulem ◽  
B.O. Olayinka
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Meca Gene ◽  
Community Settings ◽  
Potential Threat ◽  
Orthopaedic Patients ◽  
Nasal Swabs ◽  
Public Health Challenge

Biofilm formation and resistance to methicillin are among the factors that makes Staphylococcus aureus a very important human pathogen in both health-care and community settings. This study investigated methicillin-resistance among biofilm-producing S. aureus isolated from 49 orthopaedic in-patients within a 3 months period. Wound swabs, nasal swabs, bed swabs and urine samples were collected from each patient. The samples were cultured and screened for presence of S. aureus while the micro-titre plate method was used to detect biofilm producing isolates. PCR technique was finally used to detect the presence of mecA gene in methicilin resistant S. aureus (MRSA) isolates. Findings reveal 14.8% of bacterial isolates were Staphylococcus aureus of which 96.4% were biofilm-producers. However, strong biofilm producers constitute 11.1%. The mecA gene was detected in 15.8% of the MRSA isolates. Therefore, MRSA among biofilm-producing S. aureus is a potential threat primarily to the community of National Orthopaedic Hospital Dala and a major public health challenge. Keywords: Biofilm, Methicillin-resistance Staphylococcus aureus (MRSA), mecA gene, Orthopaedic patient

scholarly journals Antibiotic Sensitivity and Virulence Genes in Staphylococcus aureus Isolates from Surgical Site Infection

2021 ◽  
Vol 38 (1) ◽  
pp. 21-26
Author(s):  
Marufa Zerin Akhter ◽  
Nuheen Akter ◽  
Sunjukta Ahsan ◽  
Fatema Moni Chowdhury
Keyword(s):  
Staphylococcus Aureus ◽  
Surgical Site Infection ◽  
Virulence Genes ◽  
Methicillin Resistance ◽  
Meca Gene ◽  
Antibiotic Sensitivity ◽  
Virulence Gene ◽  
Resistance Pattern ◽  
Toxin Gene ◽  
Site Infection

Fourteen multi drug resistant Staphylococcus aureus isolates from surgical site infection were analyzed for their antibiotic sensitivity and the presence of nine virulence genes. The isolates showed a high resistance pattern, all being resistant to methicillin, oxacillin, azithromycin, ceftazidime and amoxyclav. Seven of the isolates were sensitive to linezolid; three were sensitive to trimethoprim: sulfamethoxazol and another three were sensitive to ciprofloxacin. Ceftriaxone, gentamicin and amikacin were the drugs of choice as nine (64.3%) isolates were sensitive to ceftriaxone, eleven (78.6%) were sensitive to gentamicin and another eleven (78.6%) to amikacin. The present study focused to identify nine important virulence genes including intrinsic methicillin resistance gene mecA, methicillin resistance assisting gene femA, toxic shock syndrome toxin gene tst, exfoliative toxin A and B genes, eta and etb, Panton Valentine leukocidin gene LukS/F-PVL, along with three enterotoxin genes sec, sed and see. According to the presence of mecA gene and antibiotic resistance profile, two isolates were identified as methicillin resistant Staphylococcus aureus. However, another isolate, despite harbouring both mecA and femA genes, was sensitive to ceftriaxone which excluded it from being considered as an MRSA. Thus, the ratio of MRSA can be considered to be quite high (2/14) among the strains. Interestingly, most of the isolates (10/14) harboured femA gene, the majority of which were mecA negative with an MSSA type antibiotic profile. Although considered as a marker for community acquired MRSA, LukS/F-PV was found in half of these nosocomial isolates. Five, four and two of the isolates harboured etb, tst and sec gene, respectively. However, all the isolates were negative for eta, sed and see genes. Two isolates showed the co-existance of “femA, LukS/F-PV, etb, and tst” genes. Another two virulence gene patterns observed were “femA, mecA, tst, sec” and “femA, LukS/F-PV, etb”. The presence of several virulence genes can be correlated to the highly pathogenic nature of the isolates. Bangladesh J Microbiol, Volume 38, Number 1, June 2021, pp 21-26

scholarly journals Antibiotic Resistance Pattern and Detection of mecA Gene in Staphylococcus aureus Isolated from Iranian Hamburger Samples

2020 ◽  
Author(s):  
N. Momtaz Bokharaei ◽  
M.M. Soltan Dallal ◽  
M.R. Pourmand ◽  
Z. Rajabi
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Fast Food ◽  
Methicillin Resistance ◽  
Meca Gene ◽  
Food Poisoning ◽  
Penicillin G ◽  
Resistance Pattern ◽  
Antibiotic Resistance Pattern ◽  
Common Causes

Background: Among the bacteria that cause food poisoning, Staphylococcus aureus is one of the most common causes of food poisoning worldwide. The aim of this study was to investigate the presence of S. aureus strains in Iranian hamburgers, analysis of their antibiotic resistance pattern, and molecular detection of mecA gene in isolated strains. Methods: A total of 100 Iranian handmade (traditional) and packaged (factory-made) hamburger samples were investigated for the existence of S. aureus. The pattern of antibiotic resistance and the presence of mecA genes were investigated by disk diffusion and molecular methods, respectively. Data were statistically analyzed by SPSS software v. 24. Results: The prevalence of S. aureus isolated in handmade hamburgers was significantly (p=0.008) higher than packaged ones. Most of 39 isolated S. aureus strains were susceptible to ciprofloxacin (31 isolate), chloramphenicol (27 isolate), and trimethoprim/sulfamethoxazole (37 isolate). The highest antibiotic resistance was observed for penicillin G followed by oxacillin and tetracycline. All isolates were found susceptible to vancomycin and gentamicin. Six S. aureus isolates which were evaluated for methicillin-resistance, contained the mecA gene. Conclusion: The high presence of the S. aureus in Iranian hamburgers and the remarkable antibiotic resistance emphasize the need for policies which enforce hygienic practices within the food industry and fast food outlets.

scholarly journals Molecular Study of Enterotoxins Genes of Staphylococcus aureus Isolated from Patients in Intensive Care Units

2018 ◽  
Vol 12 (1) ◽  
pp. 381-389
Author(s):  
Maysaa El Sayed Zaki ◽  
Mohamed A. Rizk ◽  
Asmaa O. Bakr
Keyword(s):  
Staphylococcus Aureus ◽  
Intensive Care ◽  
Blood Culture ◽  
Intensive Care Units ◽  
Virulence Genes ◽  
Methicillin Resistance ◽  
Fatal Outcome ◽  
Meca Gene ◽  
Enterotoxin Genes ◽  
Healthcare Associated

Introduction:Staphylococcus aureusis responsible for healthcare-associated sepsis. Various virulence genes may be responsible for the severity of the outcome of this infection.Aims & objectives:Therefore, the aim of the present study was to investigate the prevalence of enterotoxin genes inS .aureusassociated with HCA sepsis affecting adult's patients in Intensive Care Units (ICU).Materials & Methods:The study is a cross-sectional observational study included 432 patients admitted to intensive care units with Healthcare-Associated Infections (HCAIs). The patients were subjected to blood culture and identification of the isolated bacteria according to the standard microbiological method. Isolates identified asS. aureuswere subjected to molecular studies for the detection of meca gene and enterotoxins genes by multiplex Polymerase Chain Reaction (PCR).Results & Discussion:Blood culture was positive in 170 of the patients (39.3%). 47 of the blood culture yieldS. aureu.Regarding studies of virulence genes in isolatedS. aureus, the most frequent genes were seg (61.7%), mecA (46.8%) and sea (42.6%). The less frequent genes were tst and eta 6.4% for each. Analysis of demographic, clinical and virulence genes of isolatedS. aureusto HAIs outcome reveals that the virulence genes namely mec, sei and tst ofS. aureuswere the only significant factors associated with death The distribution of enterotoxigenic genes among MRSA and MSSA shows a significant association between seg and sei genes in MRSA isolates.Conclusion:The present study highlights the prevalence of enterotoxin genes in isolated S.aureus from patients with hospital-acquired infections in intensive care units in a tertiary hospital. There was high prevalence as about two-thirds of the isolates harbor seg and sea genes in addition to methicillin resistance gene mecA. The fatal outcome of sepsis in those patients was associated with the presence of enterotoxin genes sei and tst. There is a need for screening patients admitted to intensive care units forS. aureusharboring these genes for proper management and application of isolation and contact guidelines of infection control

scholarly journals Molecular characteristics and virulence gene profiles of Staphylococcus aureus isolates in Hainan, China

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Xuehan Li ◽  
Tao Huang ◽  
Kai Xu ◽  
Chenglin Li ◽  
Yirong Li
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Virulence Genes ◽  
Mainland China ◽  
Geographical Location ◽  
Antibiotic Resistance Genes ◽  
Virulence Gene ◽  
Molecular Characteristics ◽  
Staphylococcal Protein A

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.

Evaluation of the Role of Staphylococci in the Pathomechanism of Conjunctivitis

2021 ◽  
Author(s):  
Ewa Jasińska ◽  
Agnieszka Bogut ◽  
Agnieszka Magryś ◽  
Alina Olender
Keyword(s):  
Antibiotic Resistance ◽  
Epithelial Cells ◽  
Biofilm Formation ◽  
Methicillin Resistance ◽  
Microtiter Plate ◽  
Host Cells ◽  
Diffusion Method ◽  
Microtiter Plate Assay ◽  
Low Prevalence

Abstract Purpose: Determination of the association between ica genes and phenotypic biofilm formation in staphylococcal isolates involved in conjunctivitis, their antibiotic resistance as well as detection of selected virulence characteristics: adhesion to epithelial cells and in vitro cytotoxicity.Methods: The study included 26 Staphylococcus aureus (SA) and 26 Staphylococcus epidermidis (SE) isolates. The presence of icaAD genes and ica operon was determined by the PCR assay. Phenotypic biofilm formation was verified using the microtiter plate assay. Antibiotic resistance was performed using the disc diffusion method. Staphylococcal ability to attach to host cells was assessed by flow cytometry. Cytotoxicity on epithelial cells was evaluated by LDH assay.Results: The ica genes were detected in 26.9% of SE and in 42.3% of SA isolates. Only 15.3% of isolates (SE) were positive for both the icaAD and the ica operon. Phenotypically, 19.2% of SE isolates were strong biofilm producers, among which three were both icaAD- and ica operon-positive. 26.9% of SA isolates were strong biofilm producers. Methicillin resistance (MR) was detected in 34.6% of SE and 26.9% of SA isolates. 75% of MR isolates were multidrug resistant. SA isolates adhered to host cells more extensively than SE. SA isolates released higher level of LDH than SE.Conclusions: Adherence abilities were commonly observed in staphylococci associated with conjunctivitis. However, low prevalence of isolates positive for a complete and functional ica locus and low prevalence of strong biofilm producers was detected. SA adhered to a greater extent to eukaryotic cells than SE and were more cytotoxic.

Investigation of the antibiotic resistance of staphylococcus species isolated from foods

2021 ◽  
Vol 67 (2) ◽  
pp. 3372-3382
Author(s):  
Brigitta Horváth ◽  
Ferenc Peles ◽  
Judit Gasparikné Reichardt ◽  
Edit Pocklán ◽  
Rita Sipos ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Methicillin Resistance ◽  
Multidrug Resistant ◽  
Farm Animals ◽  
The European Union ◽  
Methicillin Resistant ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

The presence of methicillin-resistant Staphylococcus aureus (MRSA) strains in the food chain has been confirmed by several studies in the European Union, but there are only limited data available in Hungary. The objective of the present study was to investigate the antibiotic resistance of Staphylococcus strains isolated from foods, using classical microbiological, molecular biological methods and the MALDI-TOF-MS technique, as well as the multi-locus sequence typing (MLST) of antibiotic resistant strains. During the study, 47 coagulase-positive (CPS) and 30 coagulase-negative (CNS) Staphylococcus isolates were collected. In the course of the MALDI-TOF-MS investigations, all CPS isolates (n=47) were found to be S. aureus species, while 8 different species were identified in the case of the CNS strains. Methicillin resistance was confirmed in two S. aureus strains, one of which had a sequence type not yet known, while the other MRSA strain was type ST398, which is the most common type of MRSA strain isolated from farm animals in the EU/EEA. (The abbreviation “MRSA” is often used in common parlance, but occasionally in the literature to denote “multidrug-resistant Staphylococcus aureus”. In the authors’ manuscript - the methicillin-resistant pathogen is correctly designated as such. Ed.)

scholarly journals Detection of β-lactamase, blaZ and mecA in penicillin-resistant Staphylococcus aureus isolated from bovine mastitis in Garanhuns, Brazil

2021 ◽  
Vol 15 (2) ◽  
pp. 140-145
Author(s):  
Amanda Pereira Lucas ◽  
Andriele Renata Barbosa de Farias ◽  
Elizabete Cristina da Silva ◽  
Kleber Régis Santoro ◽  
Marcelo Mendonça ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Cattle ◽  
Meca Gene ◽  
Resistance Mechanism ◽  
Bovine Mastitis ◽  
Duplex Pcr ◽  
Genetic Determinants ◽  
The City

There are few reports in the literature about genetic determinants of resistance to β-lactams in Staphylococcus aureusisolated from dairy cattle located in the municipality of Garanhuns, state of Pernambuco, Brazil. Thus, this study aimed to investigate the production of β-lactamase and the presence of the blaZ and mecA genes in penicillin-resistant S. aureus isolated from cases of subclinical bovine mastitis in the city of Garanhuns. Forty-six strains of penicillin-resistant S. aureus were evalu-ated using the nitrocefin disc test and duplex PCR. The results revealed that 45 strains (97.8%) were positive for β-lactamase production and 44 (95.7%) carried the blaZ gene. Among the latter, 43 (97.7%) were β-lactamase producers and only one (2.3%) was not. The mecA gene was not detected in any of the isolates investigated. The results suggest that enzymatic inacti-vation is the main β-lactam resistance mechanism expressed by S. aureus in the herds analyzed.

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