Molecular detection of enterotoxins E, G, H and I in Staphylococcus aureus and coagulase-negative staphylococci isolated from clinical samples of newborns in Brazil

The purpose of the present study was to assess the agreement at the categorical level between the VITEK ® 2 system and the Colibri TM coupled to the Radian TM under real routine laboratory conditions. The 675 non-duplicate clinical strains included in this study (249 Enterobacterales-isolates, 198 Pseudomonas aeruginosa , 107 Staphylococcus aureus , 78 coagulase-negative staphylococci, 38 Enterococcus faecalis and 5 Enterococcus faecium ) were isolated from non-consecutive clinical samples referred to our laboratory between June and November 2020. In addition, 43 carbapenemase-producing Enterobacterales (CPE) formerly identified and stored in our laboratory were added to the panel, for a total of 718 strains. The overall categorical agreements between the two compared methods were 99.3% (4350/4380; 95% CI 99% - 99.5%); 98.6% (2147/2178; 95% CI 98.0% - 99.0%); 99.4% (1839/1850; 95% CI 98.9% - 99.7%); and 99.4% (342/344; 95% CI 97.9% - 99.8%) for Enterobacterales, P. aeruginosa , Staphylococcus spp. and Enterococcus spp. respectively. The most important cause of the very major errors encountered on the VITEK ® 2 for P. aeruginosa (62%, 13/21) was related to the presence of heteroresistant populations. Among the 43 CPE included in this study, one OXA-48-like, and one OXA-181-like were missed by the VITEK ® 2, even by rigorously applying the CPE screening cut-offs defined by EUCAST. The Colibri TM coupled to the Radian TM provide a fully automated solution for antimicrobial disk diffusion susceptibility testing with an accuracy that is equal to or better than that of the VITEK ® 2 system.

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The Prevalence of antimicrobial resistance in Staphylococcus aureus and coagulase-negative Staphylococci strains isolated from inpatients

10.21203/rs.3.rs-24115/v1 ◽

2020 ◽

Author(s):

Parva Farmehr ◽

Javad fathi ◽

Mahtab Hadadi ◽

mohammad motamedifar

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Susceptibility ◽

Antibacterial Agents ◽

Methicillin Resistance ◽

Cross Sectional Study ◽

Clinical Samples ◽

Coagulase Negative Staphylococci ◽

Cross Sectional ◽

Antibiotic Policy ◽

Southwest Of Iran

Abstract Objectives Globally nosocomial infection is a significant problem. Methicillin resistance Staphylococcus aureus (MRSA) and Methicillin resistance coagulase negative staphylococci (MRCoNS) are major causes of nosocomial infections. Aim of this study was to determine the prevalence and antimicrobial susceptibility of MRSA and MRCoNS in the southwest of Iran. This cross-sectional study was conducted on 221 non-duplicated staphylococci isolates collected from teaching hospital in Shiraz. The prevalence of MRSA and MRCoNS in clinical samples was identified with conventional microbiological tests. After identification, all of the isolates were subjected to antimicrobial susceptibility test and PCR to identify the presence of femA, mecA and pvl genes.Result 168 (76%) S. aureus and 53 (24%) CoNS were detected. 70 (41.7%) MRSA among 168 S. aureus, and 26 (15.48%) MRCoNS among 53 CoNS were examined. Chloramphenicol (65%) and Gentamicin (23%) were the most active antibacterial agents against MRSA and MRCoNS, whereas these isolates were susceptible to SXT (100%). The frequency of pvl gene among S. aureus strains was 3.57%. There is need for developing the antibiotic policy and limiting the use of powerful antibiotics.

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Molecular Detection of Staphylococcus aureus Enterotoxin A and B Genes in Clinical Samples from Patients Referred to Health Centers in Zahedan City

Research in Molecular Medicine ◽

10.18869/acadpub.rmm.4.2.44 ◽

2016 ◽

Vol 4 (2) ◽

pp. 44-46 ◽

Cited By ~ 1

Author(s):

Mohammad Bokaeian ◽

Saeide Saeidi ◽

Mehdi Hassanshahian ◽

◽

...

Keyword(s):

Staphylococcus Aureus ◽

Molecular Detection ◽

Health Centers ◽

Clinical Samples

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The Prevalence of antimicrobial resistance in Staphylococcus aureus and coagulase-negative Staphylococci strains isolated from inpatients

10.21203/rs.3.rs-24115/v2 ◽

2020 ◽

Author(s):

Parva Farmehr ◽

Javad fathi ◽

Mahtab Hadadi ◽

mohammad motamedifar

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Susceptibility ◽

Antibacterial Agents ◽

Cross Sectional Study ◽

Clinical Samples ◽

Coagulase Negative Staphylococci ◽

Cross Sectional ◽

Antibiotic Policy ◽

Methicillin Resistant ◽

Southwest Of Iran

Abstract Objectives: Globally nosocomial infection is a significant problem. Methicillin resistant Staphylococcus aureus (MRSA) and Methicillin resistant coagulase negative staphylococci (MRCoNS) are major causes of nosocomial infections. Aim of this study was to determine the prevalence and antimicrobial susceptibility of MRSA and MRCoNS in the southwest of Iran. This cross-sectional study was conducted on 221 non-duplicated staphylococci isolates collected from teaching hospital in Shiraz. The prevalence of MRSA and MRCoNS in clinical samples was identified with conventional microbiological tests. After identification, all of the isolates were subjected to antimicrobial susceptibility test and PCR to identify the presence of femA, mecA and pvl genes. Results: 70 (41.7 %) MRSA among 168 S. aureus, and 26 (15.48%) MRCoNS among 53 CoNS were examined. All of the isolates were susceptible to Trimethoprim/Sulfamethoxazole (100%). Chloramphenicol (65%) and Gentamicin (23%) were the other most active antibacterial agents against MRSA and MRCoNS. The frequency of pvl gene among S. aureus strains was 3.57%. There is need for developing the antibiotic policy and limiting the use of powerful antibiotics.

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Dominance of Staphylococcus aureus in clinical specimens in Islami bank hospital, Rajshahi, Bangladesh

International Journal of Scientific Reports ◽

10.18203/issn.2454-2156.intjscirep20173091 ◽

2017 ◽

Vol 3 (7) ◽

pp. 200

Author(s):

M. Jakir Hossain ◽

Muhammad Afser Siddiqi ◽

M. Morsed Zaman Miah ◽

Khairun Nahar Khan ◽

Ahmed Imtiaj

Keyword(s):

Staphylococcus Aureus ◽

Pathogenic Bacteria ◽

Health Workers ◽

Small Sample Size ◽

Small Sample ◽

Clinical Samples ◽

Coagulase Negative Staphylococci ◽

Isolation And Identification ◽

Mortality And Morbidity ◽

High Incidence

Background: Staphylococcus aureus is a medicologically important pathogenic bacteria which is largely responsible for the thousands of human health hazzards. This study investigated the incidence of Staphylococcus aureus in various clinical samples from in- and outpatients attending Islami Bank Hospital, Rajshahi, Bangladesh.Methods: Clinical isolates from the hospital was confirmed as Staphylococcus aureus using standard bacteriological techniques. This study reports the isolation and identification of Staphylococcus aureus, coagulase negative staphylococci and catalase negative cocci in clinical samples at Islami Bank Hospital, Rajshahi, Bangladesh. Results: Out of a total of 144 putative isolates of Staphylococci from urine, ear and wounds screened for Staphylococcus aureus, 87 of them were confirmed as S. aureus, 30 were coagulase negative staphylococci while 27 were catalase negative cocci. The high incidence of S aureus in this study compared to other staphylococci demonstrates the versatility and propensity of S. aureus to cause diseases.Conclusions: This is worrisome because of the high mortality and morbidity often associated with infections of this bacterium. It therefore calls for proper handling of specimen suspected to contain the organism or patients who might be at risk of infection. This is to avoid transmission to other patients and healthy individuals especially health workers as they might constitute vehicles for the spread of the organism. Further studies are recommended because of the small sample size in this study. This would help to establish whether this was peculiar to the Islami Bank Hospital Rajshahi, Bangladesh or wide spread in other hospitals in the country.

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First Record of Isolation and Characterization of Methicillin ResistantStaphylococcus lugdunensisfrom Clinical Samples in Iraq

BioMed Research International ◽

10.1155/2014/736259 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Alaa H. Al-Charrakh ◽

Mohammed H. Obayes

Keyword(s):

Molecular Detection ◽

Susceptibility Testing ◽

First Record ◽

Clinical Samples ◽

Antibiotic Susceptibility Testing ◽

Coagulase Negative Staphylococci ◽

Staphylococcus Lugdunensis ◽

Isolation And Characterization ◽

Resistance Rates

This study was conducted to determine the frequency ofStaphylococcus lugdunensisin different clinical samples. Out of 690 clinical samples, a total of 178 coagulase negative staphylococci (CoNS) isolates were recovered. CoNS were identified as 10 different species; 22 isolates belonged toStaphylococcus lugdunensis. Two specific genes forS. lugdunensiswere used (tanAgene andfblgene) to confirm identification. Both of these specific genes were detected in 15 (68.1%) of 22 isolates that were identified phenotypically. The results of oxacillin MIC showed that 7 of the 15 (46.6%)S. lugdunensisisolates were oxacillin resistant. The antibiotic susceptibility testing against 16 antibiotics showed that resistance rates were variable towards these antibiotics. Eight of fifteenS. lugdunensisisolates (53.3%) wereβ-lactamase producer. Results of molecular detection ofmecAgene found thatmecAgene was detected in 6 (40%) of 15S. lugdunensis. All of these 6 isolates (S1, S2, S3, S4, S5, and S6) were resistant to oxacillin. One isolate (S7) was resistant to oxacillin butmecAwas not detected in this isolate. This study is a first record of isolation and characterization of methicillin resistantS. lugdunensis(MRSL) from clinical samples in Iraq.

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Faculty Opinions recommendation of Practical disk diffusion method for detection of inducible clindamycin resistance in Staphylococcus aureus and coagulase-negative staphylococci.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1013359.200155 ◽

2003 ◽

Author(s):

Gary Lum

Keyword(s):

Staphylococcus Aureus ◽

Disk Diffusion ◽

Diffusion Method ◽

Coagulase Negative Staphylococci ◽

Disk Diffusion Method ◽

Inducible Clindamycin Resistance

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Nasopharyngeal Carriage of Methicillin-Resistant Staphylococcus aureus (MRSA) among Sickle Cell Disease (SCD) Children in the Pneumococcal Conjugate Vaccine Era

Infectious Disease Reports ◽

10.3390/idr13010022 ◽

2021 ◽

Vol 13 (1) ◽

pp. 191-204

Author(s):

Nicholas T. K. D. Dayie ◽

Deborah N. K. Sekoh ◽

Fleischer C. N. Kotey ◽

Beverly Egyir ◽

Patience B. Tetteh-Quarcoo ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Sickle Cell Disease ◽

Conjugate Vaccine ◽

Sickle Cell ◽

Pneumococcal Conjugate Vaccine ◽

Diffusion Method ◽

Nasopharyngeal Carriage ◽

Cell Disease ◽

Coagulase Negative Staphylococci ◽

Methicillin Resistant

The aim of this cross-sectional study was to investigate Staphylococcus aureus nasopharyngeal carriage epidemiology in relation to other nasopharyngeal bacterial colonizers among sickle cell disease (SCD) children about five years into pneumococcal conjugate vaccine 13 (PCV-13) introduction in Ghana. The study involved bacteriological culture of nasopharyngeal swabs obtained from 202 SCD children recruited from the Princess Marie Louise Children’s Hospital. S. aureus isolates were identified using standard methods and subjected to antimicrobial susceptibility testing using the Kirby-Bauer disc diffusion method. Cefoxitin-resistant S. aureus isolates were screened for carriage of the mecA, pvl, and tsst-1 genes using multiplex polymerase chain reaction. The carriage prevalence of S. aureus was 57.9% (n = 117), and that of methicillin-resistant S. aureus (MRSA) was 3.5% (n = 7). Carriage of the mecA, pvl, and tsst-1 genes were respectively demonstrated in 20.0% (n = 7), 85.7% (n = 30), and 11.4% (n = 4) of the cefoxitin-resistant S. aureus isolates. PCV-13 vaccination (OR = 0.356, p = 0.004) and colonization with coagulase-negative staphylococci (CoNS) (OR = 0.044, p < 0.0001) each protected against S. aureus carriage. However, none of these and other features of the participants emerged as a determinant of MRSA carriage. The following antimicrobial resistance rates were observed in MRSA compared to methicillin-sensitive S. aureus: clindamycin (28.6% vs. 4.3%), erythromycin (42.9% vs. 19.1%), tetracycline (100% vs. 42.6%), teicoplanin (14.3% vs. 2.6%), penicillin (100% vs. 99.1%), amoxiclav (28.6% vs. 3.5%), linezolid (14.3% vs. 0.0%), ciprofloxacin (42.9% vs. 13.9%), and gentamicin (42.9% vs. 13.0%). The proportion of S. aureus isolates that were multidrug resistant was 37.7% (n = 46). It is concluded that S. aureus was the predominant colonizer of the nasopharynx of the SCD children, warranting the continuous monitoring of this risk group for invasive S. aureus infections.

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

Pharmaceuticals ◽

10.3390/ph14050420 ◽

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.

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