scholarly journals Evaluation of disc diffusion tests and agar screening for predicting mecA-mediated oxacillin resistance in Staphylococcus lugdunensis revealed a cefoxitin-susceptible, mecA-positive S. lugdunensis clonal complex 27 clone

2020 ◽  
Vol 20 ◽  
pp. 260-265
Author(s):  
Pak-Leung Ho ◽  
Melissa Chun-Jiao Liu ◽  
Man-Ki Tong ◽  
Pui-Man Fan ◽  
Cindy Wing-Sze Tse ◽  
...  
Keyword(s):  
Clonal Complex ◽  
Disc Diffusion ◽  
Staphylococcus Lugdunensis ◽  
Oxacillin Resistance

Antimicrobial Susceptibility Testing for Staphylococcus lugdunensis

2021 ◽  
Author(s):  
Joanne S.K. Teh ◽  
Ioanna Pantelis ◽  
Xiao Chen ◽  
Tania Sadlon ◽  
Kelly Papanaoum ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Resistant Isolate ◽  
Disc Diffusion ◽  
Broth Microdilution ◽  
Major Error ◽  
Staphylococcus Lugdunensis ◽  
Zone Diameter ◽  
Oxacillin Resistance ◽  
Zone Edge

Evaluation of penicillin and oxacillin susceptibility testing was conducted on two hundred Staphylococcus lugdunensis isolates. Disc diffusion with penicillin 1 IU (P1, EUCAST) and penicillin 10 IU (P10, CLSI) was compared with nitrocefin discs (Cefinase®) and automated broth microdilution (Vitek2®). Oxacillin susceptibility was extrapolated from cefoxitin 30μg disc diffusion (FOX) and compared with Vitek2®. Reference methods were blaZ and mecA PCR. Penicillin zone diameter and zone edge correlated with blaZ in all except two P10 susceptible isolates (VME; very major error) and one P1 resistant isolate (ME). One hundred and forty-eight isolates were blaZ -negative of which one hundred and forty-six and one hundred and forty-nine isolates were susceptible by P1 and P10 respectively. One hundred and twenty-seven isolates were penicillin susceptible by Vitek2®. Vitek2® overcalled resistance in twenty-one blaZ -negative, twenty P1 and twenty-two P10 susceptible isolates (Vitek2® ME rate, 14.2%). Two mecA -positive isolates were oxacillin resistant by FOX and Vitek2® (categorical agreement). However, eighteen FOX susceptible, mecA -negative isolates tested resistant by Vitek2®. In conclusion, Vitek2® over-estimated penicillin and oxacillin resistance compared with disc diffusion and PCR. Disc diffusion with zone edge interpretation was more accurate and specific than automated broth microdilution for S. lugdunensis in our study.

scholarly journals MecA gene and methicillin-resistant Staphylococcus aureus (MRSA) isolated from dairy farms in East Java, Indonesia

2020 ◽  
Vol 21 (8) ◽  
Author(s):  
Sancaka Chasyer Ramandinianto ◽  
Aswin Rafif Khairullah ◽  
Mustofa Helmi Effendi
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Dairy Farms ◽  
Detection Methods ◽  
Disc Diffusion ◽  
Mannitol Salt Agar ◽  
Methicillin Resistant ◽  
Oxacillin Resistance

Abstract. Ramandinianto SC, Khairullah AR, Effendi MH. 2020. MecA gene and methicillin-resistant Staphylococcus aureus (MRSA) isolated from dairy farms in East Java, Indonesia. Biodiversitas 21: 3562-3568. Milk Borne Disease (MBD) can be caused by a variety of pathogenic bacteria, one of which is Staphylococcus aureus which has a large impact on aspects of public health. The therapy used to treat staphylococcal infection is Oxacillin preparations that can inhibit bacterial wall synthesis, but the adaptation of the mecA gene to staphylococcal cassette chromosome mec (SCCmec) causes the emergence of strains of methicillin-resistant S. aureus (MRSA). The purpose of this study was to detect the level of MRSA strain contamination in dairy cows in East Java by comparing the mecA gene, Oxacillin, and Cefoxitin Disc Diffusion Methods and Oxacillin Resistance Screen Agar (ORSA) detection methods. A total of 150 cow's milk samples were taken at 3 village dairy farms in East Java, samples were added to the enrichment media Buffer Pepton Water (BPW) and then isolates were planted and purified using Mannitol Salt Agar (MSA). The detection of MRSA was carried out by the Kirby Bauer disc diffusion preparation Cefoxitin 30 μg and Oxacillin 30 μg then confirmed by ORSA and the presence of mecA gene by the polymerase chain reaction (PCR) method. The results showed that from a total of 92 S. aureus isolates using Oxacillin disc test, 24 resistant isolates were obtained, using Cefoxitin disc test, 17 isolates were obtained, and using the ORSA test 18 MRSA isolates were obtained. MRSA isolates tested by PCR obtained evidence of 2 isolates of mecA gene. It can be concluded that the Oxacillin disc test was the highest sensitivity for detecting MRSA strain isolate, however, mecA gene was the golden standard to detect MRSA on the dairy farms.

scholarly journals Improved Detection of mecA-Mediated β-Lactam Resistance in Staphylococcus lugdunensis Using a New Oxacillin Salt Agar Screen

2021 ◽  
Vol 12 ◽  
Author(s):  
Pak-Leung Ho ◽  
Ying-Hang Law ◽  
Melissa Chun-Jiao Liu ◽  
Andes Lau ◽  
Man-Ki Tong ◽  
...  
Keyword(s):  
Population Analysis ◽  
Sequence Type ◽  
Penicillin Binding Protein ◽  
Becton Dickinson ◽  
Staphylococcus Lugdunensis ◽  
Low Frequencies ◽  
Oxacillin Resistance ◽  
Reliable Detection ◽  
Cefoxitin Disk ◽  
Cefoxitin Disk Diffusion

Oxacillin resistance mediated by mecA in Staphylococcus lugdunensis is emerging in some geographic areas. We evaluated cefoxitin disk diffusion (DD) and a new oxacillin agar (supplemented with 2 μg/ml oxacillin and 2% sodium chloride) screen for the detection of mecA-mediated resistance in S. lugdunensis. A total of 300 consecutive, non-duplicated clinical S. lugdunensis isolates from diverse sources in Hong Kong in 2019 were tested. The categorical agreement and errors obtained between cefoxitin DD test, oxacillin agar screen and mecA PCR were analyzed. Isolates with discordant results were further tested by MIC, penicillin binding protein 2a (PBP2a) assays, population analysis and molecular typing. PCR showed that 62 isolates were mecA-positive and 238 isolates were mecA-negative. For cefoxitin DD results interpreted using S. aureus/S. lugdunensis breakpoints, the categorical agreement (CA) for two brands of Muller-Hinton agars, MH-II (Becton Dickinson) and MH-E (bioMérieux) were both 96.0%; MEs were both 0%; and VMEs were 19.4 and 12.9%, respectively. The new oxacillin agar reliably differentiated mecA-positive and mecA-negative isolates (100% CA) without any ME or VME results. The 8 isolates with false susceptibility in the cefoxitin DD testing had cefoxitin and oxacillin MICs in the susceptible range. The isolates showed heterogeneous oxacillin resistance with resistant subpopulations at low frequencies. All had positive PBP2a results and were typed as sequence type 27/SCCmec V. The findings highlight the inability of cefoxitin DD and MIC tests for reliable detection of some mecA-positive S. lugdunensis isolates.

scholarly journals Evaluation of penicillin G susceptibility testing methods for Staphylococcus lugdunensis

2020 ◽  
Vol 75 (5) ◽  
pp. 1206-1211
Author(s):  
Malin Hagstrand Aldman ◽  
Lisa I Påhlman
Keyword(s):  
Susceptibility Testing ◽  
Reference Method ◽  
Penicillin G ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Diffusion Test ◽  
Staphylococcus Lugdunensis ◽  
Susceptible Isolate ◽  
Focus Of Infection ◽  
Zone Edge

Abstract Background Staphylococcus lugdunensis belongs to the CoNS group, but is regarded to be more virulent than most other CoNS. It is also remarkably susceptible to antibiotics, including penicillin G. Objectives To evaluate different methods for penicillin susceptibility testing, to assess penicillin susceptibility rates among S. lugdunensis and to describe the clinical presentation including antibiotic treatment. Methods Clinical isolates of S. lugdunensis were tested for penicillin susceptibility using disc diffusion according to CLSI (10 U disc) and EUCAST (1 U disc), assessment of zone-edge appearance, nitrocefin test and Etest for MIC determination. PCR of the blaZ gene was used as a reference method. Results Of the 112 isolates included in the study, 67% were susceptible to penicillin G according to blaZ PCR. The EUCAST disc diffusion test had 100% sensitivity, whereas the CLSI method had one very major error with a false-susceptible isolate. When zone-edge appearance was included in the assessment, the false-susceptible isolate was correctly classified as resistant. Foreign-body infection was the most common focus of infection, affecting 49% of the participants. Only 4% of the patients were treated with penicillin G. Conclusions Penicillin susceptibility is common in S. lugdunensis and the disc diffusion method according to EUCAST had a higher sensitivity than that of CLSI. Assessment of zone-edge appearance could increase the sensitivity of the disc diffusion test. Penicillin susceptibility testing and treatment should be considered in S. lugdunensis infections.

Decreased carO gene expression and OXA-type carbapenemases among extensively drug-resistant Acinetobacter baumannii strains isolated from burn patients in Tehran, Iran

2020 ◽  
Author(s):  
Elham Abbasi ◽  
Hossein Goudarzi ◽  
Ali Hashemi ◽  
Alireza Salimi Chirani ◽  
Abdollah Ardebili ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acinetobacter Baumannii ◽  
High Rate ◽  
Burn Patients ◽  
Drug Resistant ◽  
Disc Diffusion ◽  
Carbapenem Resistant ◽  
Extensively Drug Resistant ◽  
Sds Page ◽  
Extensively Drug Resistance

AbstractA major challenge in the treatment of infections has been the rise of extensively drug resistance (XDR) and multidrug resistance (MDR) in Acinetobacter baumannii. The goals of this study were to determine the pattern of antimicrobial susceptibility, blaOXA and carO genes among burn-isolated A. baumannii strains. In this study, 100 A. baumannii strains were isolated from burn patients and their susceptibilities to different antibiotics were determined using disc diffusion testing and broth microdilution. Presence of carO gene and OXA-type carbapenemase genes was tested by PCR and sequencing. SDS-PAGE was done to survey CarO porin and the expression level of carO gene was evaluated by Real-Time PCR. A high rate of resistance to meropenem (98%), imipenem (98%) and doripenem (98%) was detected. All tested A. baumannii strains were susceptible to colistin. The results indicated that 84.9% were XDR and 97.9% of strains were MDR. In addition, all strains bore blaOXA-51 like and blaOXA-23 like and carO genes. Nonetheless, blaOXA-58 like and blaOXA-24 like genes were harbored by 0 percent and 76 percent of strains, respectively. The relative expression levels of the carO gene ranged from 0.06 to 35.01 fold lower than that of carbapenem-susceptible A. baumannii ATCC19606 and SDS – PAGE analysis of the outer membrane protein showed that all 100 isolates produced CarO. The results of current study revealed prevalence of blaOXA genes and changes in carO gene expression in carbapenem resistant A.baumannii.

Nomenclature Abstract for Staphylococcus lugdunensis Freney et al. 1988.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Nicole Danielle Osier ◽  
George M Garrity
Keyword(s):  
Staphylococcus Lugdunensis

In-vitro Antioxidant and Antibacterial Activity of Methanolic Extract of Shorea robusta Gaertn. F. Resin

2016 ◽  
Vol 6 (4) ◽  
pp. 68
Author(s):  
Sushma Vashisht ◽  
Manish Pal Singh ◽  
Viney Chawla
Keyword(s):  
Antibacterial Activity ◽  
Methanolic Extract ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Disc Diffusion ◽  
Gram Positive ◽  
Gram Negative ◽  
Shorea Robusta ◽  
Dose Dependent ◽  
Resin Extract

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.

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