1
|
Abdelwahab MA, Amer WH, Elsharawy D, Elkolaly RM, Helal RAEF, El Malla DA, Elfeky YG, Bedair HA, Amer RS, Abd-Elmonsef ME, Taha MS. Phenotypic and Genotypic Characterization of Methicillin Resistance in Staphylococci Isolated from an Egyptian University Hospital. Pathogens 2023; 12:pathogens12040556. [PMID: 37111442 PMCID: PMC10143866 DOI: 10.3390/pathogens12040556] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/30/2023] [Accepted: 04/03/2023] [Indexed: 04/09/2023] Open
Abstract
Methicillin-resistant in Staphylococci is a serious public health issue. It is mostly encoded by the mecA gene. The mecC gene is a new mecA analog responsible for resistance to methicillin in some Staphylococcal clinical isolates. This mecC gene is still underestimated in Egypt. The aim of the current study was to detect mecA and mecC genes in clinical Staphylococci isolates from a tertiary care university hospital in Egypt compared to the different phenotypic methods. A total of 118 Staphylococcus aureus (S. aureus) and 43 coagulase-negative Staphylococci (CoNS) were identified from various hospital-acquired infections. Methicillin resistance was identified genotypically using the PCR technique and phenotypically using the cefoxitin disc diffusion test, oxacillin broth microdilution and the VITEK2 system in all Staphylococcal isolates. The mecA gene was detected in 82.2% of S. aureus and 95.3% of CoNS isolates, while all of the isolates tested negative for the mecC gene. Interestingly, 30.2% of CoNS isolates showed the unique character of inducible oxacillin resistance, being mecA-positive but oxacillin-susceptible (OS-CoNS). The dual use of genotypic and phenotypic methods is highly recommended to avoid missing any genetically divergent strains.
Collapse
Affiliation(s)
- Marwa A. Abdelwahab
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| | - Wesam H. Amer
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| | - Dalia Elsharawy
- Department of Chest Diseases, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| | - Reham M. Elkolaly
- Department of Chest Diseases, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| | - Rehab Abd El Fattah Helal
- Department of Anathesia, Surgical Intensive Care, and Pain Medicine, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| | - Dina Ahmed El Malla
- Department of Anathesia, Surgical Intensive Care, and Pain Medicine, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| | - Yomna G. Elfeky
- Department of Pediatrics, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| | - Hebatallah A. Bedair
- Department of Pediatrics, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| | - Rania S. Amer
- Department of Clinical Pathology, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| | - Marwa E. Abd-Elmonsef
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| | - Marwa S. Taha
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| |
Collapse
|
2
|
Fernandes LF, Souza GÁAD, Almeida ACD, Cardoso L, Xavier MADS, Pinheiro TPP, Cruz GHSD, Dourado HFS, Silva WS, Xavier AREDO. Identification and characterization of methicillin-resistant Staphylococcus spp. isolated from surfaces near patients in an intensive care unit of a hospital in southeastern Brazil. Rev Soc Bras Med Trop 2020; 53:e20200244. [PMID: 33174955 PMCID: PMC7670759 DOI: 10.1590/0037-8682-0244-2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 09/17/2020] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION: METHODS: RESULTS: CONCLUSIONS:
Collapse
|
3
|
Sharma G, Raturi K, Dang S, Gupta S, Gabrani R. Inhibitory effect of cinnamaldehyde alone and in combination with thymol, eugenol and thymoquinone against Staphylococcus epidermidis. J Herb Med 2017. [DOI: 10.1016/j.hermed.2016.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
4
|
Sharma G, Raturi K, Dang S, Gupta S, Gabrani R. Combinatorial antimicrobial effect of curcumin with selected phytochemicals on Staphylococcus epidermidis. JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH 2014; 16:535-541. [PMID: 24773066 DOI: 10.1080/10286020.2014.911289] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 03/31/2014] [Accepted: 03/31/2014] [Indexed: 06/03/2023]
Abstract
Staphylococcus epidermidis is reported to be the main causative agent of nosocomial infections. It has become increasingly difficult to treat this micro-organism because of the emergence of new antibiotic-resistant strains and its ability to form biofilm on medical associated devices. Phytochemicals acting in synergy are effective in killing the micro-organisms by lowering the doses, and synergistic compounds evade the development of resistance due to different mechanism of action. This study aims to determine the synergistic antimicrobial potential of curcumin with cinnamaldehyde, eugenol, and ellagic acid against S. epidermidis. Curcumin with ellagic acid as well as eugenol were found to have additive antimicrobial effect, whereas, in combination, curcumin and cinnamaldehyde were found to have synergistic effect against S. epidermidis (fractional inhibitory concentration index (FICI) = 0.5). Synergy between curcumin and cinnamaldehyde was established by time-kill kinetics and was further evaluated for antibiofilm activity. The dose required to inhibit biofilm formation was reduced to half than that needed to inhibit its planktonic culture (minimal inhibitory concentration (MIC) of curcumin = 3.12 μg/ml; MIC of cinnamaldehyde = 15.62 μg/ml; FICI = 0.248). Both curcumin and cinnamaldehyde disrupted the bacterial membrane for killing the bacteria as determined by permeability studies on Escherichia coli ML-35p.
Collapse
Affiliation(s)
- Garima Sharma
- a Department of Biotechnology , Jaypee Institute of Information Technology , A-10, Sector-62, Noida , India
| | | | | | | | | |
Collapse
|
5
|
Pishva E, Havaei SA, Arsalani F, Narimani T, Azimian A, Akbari M. Detection of methicillin-resistance gene in Staphylococcus epidermidis strains isolated from patients in Al-Zahra Hospital using polymerase chain reaction and minimum inhibitory concentration methods. Adv Biomed Res 2013; 2:23. [PMID: 23977651 PMCID: PMC3748670 DOI: 10.4103/2277-9175.108008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 08/26/2012] [Indexed: 11/17/2022] Open
Abstract
Background: In recent years, antibiotic resistance of Staphylococcus epidermidis to methicillin has significantly increased, making it essential to study resistance to methicillin, which is a determining factor in the appropriate treatment pattern. The purpose of this study was to identify methicillin-resistant genes in S. epidermidis strains using polymerase chain reaction (PCR) and to determine their mean minimum inhibitory concentration (MIC) to methicillin using E-test method. Materials and Methods: MIC was determined on 146 samples of S. epidermidis using E-test method. Moreover, all samples were tested for the presence of mecA gene using PCR. Results: PCR test showed 75.34% of the samples to contain mecA gene. Methicillin resistance test was performed using E-test on all the samples, which showed resistance in different dilutions. Conclusion: The frequency of mecA gene in S. epidermidis isolates was 75.34%. Among the various applied tests used for determining methicillin resistance, sensitivity and specificity of PCR were the highest and reached 100%. Sensitivity and specificity were found to be 95.3% and 94.7%, respectively, for phenotypic test (E-test) and 86.5% and 80.9%, respectively, for disk diffusion method. Based on the above results, it seems that resistance of S. epidermidis to methicillin is on the rise, and therefore more research is warranted.
Collapse
Affiliation(s)
- Ebtehaj Pishva
- Department of Microbiology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | | | | | | | | |
Collapse
|
6
|
Prasad S, Nayak N, Satpathy G, Nag H, Venkatesh P, Ramakrishnan S, Ghose S, Nag T. Molecular & phenotypic characterization of Staphylococcus epidermidis in implant related infections. Indian J Med Res 2012; 136:483-90. [PMID: 23041744 PMCID: PMC3510897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND & OBJECTIVES The discrimination between the Staphylococcus epidermidis colonizing the deep seated indwelling devices and those which are mere commensals has always been a challenge for the clinical microbiologist. This study was aimed to characterize the S. epidermidis isolates obtained from device related infection for their phenotypic and molecular markers of virulence and to see whether these markers can be used to differentiate the pathogenic S. epidermidis from the commensals. METHODS Fifty five S. epidermidis isolates from various device related infections such as endophthalmitis following intra-ocular lens (IOL) implantation, intravascular (IV) catheter related sepsis and orthopaedic implant infections, were studied for slime production, biotyping, antibiotic sensitivity; and mec A and ica positivity by the recommended procedures. RESULTS Twenty three (41.8%) isolates were multi-drug resistant, 26 (65.2%) were slime producers, 30 (54.5%) were adherent, 23 (41.8%) possessed the intercellular adhesin (ica) gene, and 28 (50.9%) harboured the mec A gene. Biotypes I and III were the commonest, most members of which were multi- drug resistant. Twenty two (73.3%) of the 30 adherent bacteria were slime producers as opposed to only 4 (16%) of the 25 non-adherent bacteria (P<0.001). A vast majority i.e. 21 (91.3%) of the 23 ica positive organisms were adherent to artificial surfaces in contrast to only 9 (28.1%) of the 32 non-ica positive organisms (P<0.001). Twenty (86.9%) of the 23 ica positive bacteria were slime producers, as opposed to only 6 (18.7%) of the 32 ica negative bacteria (P<0.001). Of the 23 multi-drug resistant isolates, 19 (82.6%) carried the mec A gene. INTERPRETATION & CONCLUSIONS The present findings showed that ica AB and mec A were the two important virulence markers of S. epidermidis in implant infections and slime was responsible for the sessile mode of attachment on the devices.
Collapse
Affiliation(s)
- Sujata Prasad
- Department of Ocular Microbiology, Dr R.P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - N. Nayak
- Department of Ocular Microbiology, Dr R.P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India,Reprint requests: Dr Niranjan Nayak, Professor, Department of Ocular Microbiology, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110 029, India e-mail:
| | - G. Satpathy
- Department of Ocular Microbiology, Dr R.P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - H.L. Nag
- Department of Orthopaedic Surgery, All India Institute of Medical Sciences, New Delhi, India
| | - P. Venkatesh
- Department of Uvea & Retina Services, Dr R.P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - S. Ramakrishnan
- Department of Cardiology, All India Institute of Medical Sciences, New Delhi, India
| | - Supriyo Ghose
- Pediatric Ophthalmology Services, Dr R.P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - T.C. Nag
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
| |
Collapse
|
7
|
Bhargava K, Zhang Y. Multidrug-resistant coagulase-negative Staphylococci in food animals. J Appl Microbiol 2012; 113:1027-36. [PMID: 22816491 DOI: 10.1111/j.1365-2672.2012.05410.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 07/13/2012] [Accepted: 07/16/2012] [Indexed: 01/22/2023]
Abstract
AIMS To study the antimicrobial resistance of coagulase-negative staphylococci (CoNS) in animals. METHODS AND RESULTS In the present study, a total of 87 CoNS recovered from food animals were characterized by antimicrobial susceptibility testing, resistance gene identification and conjugation. Of the seven species studied, Staphylococcus lentus, Staphylococcus sciuri, Staphylococcus xylosus and Staphylococcus haemolyticus accounted for over 96% of the isolates. In addition to β-lactam resistance (100%), high percentages of CoNS were resistant to tetracycline (67·8%), erythromycin (36·7%), clindamycin (27·5%) and quinopristin/dalfopristin (14·9%). Importantly, 47 (54%) isolates were resistant to at least three antimicrobial classes, including six CoNS resistant to six antimicrobial classes. The common genes for the above-mentioned resistance phenotypes were mec(A), tet(M), erm(A) and vga(A)(LC) , which were identified from 68·7%, 61%, 56·2% and 69·2% of the isolates, respectively. tet(M) was conjugatively transferable from 10 tetracycline-resistant CoNS to a Enterococcus strain, underlining the potential of antimicrobial resistance transfer from Staphylococcus to the commensal bacteria in human. CONCLUSIONS Multidrug resistance and resistance to non-β-lactam antimicrobials are common in CoNS in animals. SIGNIFICANCE AND IMPACT OF THE STUDY The data improve our understanding on the extent to which CoNS contribute to the dissemination of antimicrobial resistance in the food production environment.
Collapse
Affiliation(s)
- K Bhargava
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI, USA
| | | |
Collapse
|
8
|
Larsen J, Imanishi M, Hinjoy S, Tharavichitkul P, Duangsong K, Davis MF, Nelson KE, Larsen AR, Skov RL. Methicillin-resistant Staphylococcus aureus ST9 in pigs in Thailand. PLoS One 2012; 7:e31245. [PMID: 22363594 PMCID: PMC3281948 DOI: 10.1371/journal.pone.0031245] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 01/05/2012] [Indexed: 11/19/2022] Open
Abstract
Background Methicillin-resistant Staphylococcus aureus (MRSA) is an important nosocomial and community-associated pathogen. Recently, livestock-associated MRSA (LA-MRSA) has emerged and disseminated in Europe and North America and now constitutes a considerable zoonotic burden in humans with risk factors of pig exposure, whereas the extent of the livestock reservoir is relatively unknown on other continents. Methodology/Principal Findings From March through April 2011, MRSA was identified in pigs from 3 out of 30 production holdings in Chang Mai Province, Thailand. Representative isolates were subjected to molecular characterization and antimicrobial susceptibility testing; all isolates had genotypic and phenotypic characteristics of LA-MRSA previously characterized in the region: they belonged to ST9, lacked the lukF-lukS genes encoding Panton-Valentine leukocidin, and were resistant to multiple non-β-lactam antimicrobials. However, unlike other Asian LA-MRSA-ST9 variants, they were spa type t337 and harbored a different staphylococcal cassette chromosome mec IX. Conclusions/Significance A novel MRSA-ST9 lineage has been established in the pig population of Thailand, which differs substantially from LA-MRSA lineages found in other areas of the continent. The emergence of novel LA-MRSA lineages in the animal agriculture setting is worrisome and poses a serious threat to global public health.
Collapse
Affiliation(s)
- Jesper Larsen
- Department of Microbiological Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark.
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Rigatti F, Tizotti MK, Hörner R, Domingues VO, Martini R, Mayer LE, Khun FT, de França CA, da Costa MM. [Oxacillin-resistant coagulase-negative Staphylococci bacteremia at a teaching hospital in Santa Maria, State of Rio Grande do Sul, Brazil]. Rev Soc Bras Med Trop 2011; 43:686-90. [PMID: 21181024 DOI: 10.1590/s0037-86822010000600017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Accepted: 09/01/2010] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION This study aimed to characterize the prevalence and susceptibility profile to oxacillin-resistant Coagulase-negative Staphylococci strains isolated from blood cultures in a teaching hospital, located in Santa Maria, RS. In addition, different methodologies for phenotypic characterization of mecA-mediated oxacillin resistance were compared with genotypic reference testing. METHODS After identification (MicroScan - Siemens), the isolates were tested for antimicrobial sensitivity using disk diffusion and automation (MicroScan - Siemens). The presence of mecA gene was identified by the polymerase chain reaction molecular technique. RESULTS The most common species was Staphylococcus epidermidis (n=40, 67%). The mecA gene was detected in 54 (90%) strains, while analysis of the sensitivity profiles revealed a high rate of resistance to multiple classes of antimicrobial drugs. However, all isolates were uniformly sensitive to vancomycin and tigecycline. The cefoxitin disk was the phenotypic method that best correlated with the gold standard. CONCLUSIONS Analysis of the clinical significance of CoNS isolated from hemocultures and the precise detection of oxacillin resistance represent decisive factors for the correct choice of antibiotic therapy. Although vancomycin constitutes the normal treatment in most Brazilian hospitals, reduction in its use is recommended.
Collapse
|
10
|
Eftekhar F, Raei F. Correlation of Minimum Inhibitory Concentration Breakpoints and Methicillin Resistance Gene Carriage in Clinical Isolates of Staphylococcus epidermidis. IRANIAN JOURNAL OF MEDICAL SCIENCES 2011; 36:213-6. [PMID: 23359643 PMCID: PMC3556765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 01/05/2011] [Accepted: 02/27/2011] [Indexed: 12/01/2022]
Abstract
Staphylococcus epidermidis is the most important member of coagulase negative staphylococci responsible for community and hospital acquired infections. Most clinical isolates of S. epidermidis are resistant to methicillin making these infections difficult to treat. In this study, correlation of methicillin resistance phenotype was compared with methicillin resistance (mecA) gene carriage in 55 clinical isolates of S. epidermidis. Susceptibility was measured by disc diffusion using methicillin discs, and minimum inhibitory concentrations (MIC) were measured using broth microdilution. Methicillin resistance gene (MecA gene) carriage was detected by specific primers and PCR. Disc susceptibility results showed 90.9% resistance to methicillin. Considering a MIC of 4 µg/ml, 78.1% of the isolates were methicillin resistant, 76.36% of which carried the mecA gene. On the other hand, when a breakpoint of 0.5 µg/ml was used, 89.09% were methicillin resistant, of which 93.75% were mecA positive. There was a better correlation between MIC of 0.5 µg/ml with disc diffusion results and mecA gene carriage. The findings suggest that despite the usefulness of molecular methods for rapid diagnosis of virulence genes, gene carriage does not necessarily account for virulence phenotype. Ultimately, gene expression, which is controlled by the environment, would determine the outcome.
Collapse
|
11
|
Kaiser TDL, Pacheco FC, Lima AAD, Pereira EM, Santos KRND, Nunes APF. [Evaluation of methods commonly used in laboratories to determine the susceptibility to oxacillin among Staphylococcus sp samples isolated from a hospital in Vitória, State of Espírito Santo]. Rev Soc Bras Med Trop 2010; 43:298-303. [PMID: 20563500 DOI: 10.1590/s0037-86822010000300017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Accepted: 04/26/2010] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION The genus Staphylococcus is of great importance because of its high prevalence in hospital infections and because it presents high rates of resistance to oxacillin and other antimicrobials. Thus, evaluation of the accuracy of the phenotypic methods that are used to determine the profile of antimicrobial resistance is essential to ensure that the most appropriate therapy is chosen. METHODS One hundred and fourteen strains of Staphylococcus sp (53 S. aureus and 61 CNS) were used to evaluate the accuracy of the methods of disk diffusion, agar microdilution, oxacillin screening agar and automated systems, in comparison with PCR for investigating resistance to oxacillin. RESULTS The mecA gene was detected in 48 strains (42.1%), and 27 strains (23.7%) showed discrepant results in at least one of the methods (74.1% of CNS, 25.9% of S. aureus). For S. aureus, with the exception of the Microscan Walkaway, all the methods showed 100% specificity and sensitivity. In relation to CNS, the automated system and cefoxitin disk had lower accuracy. CONCLUSIONS Use of two methods should be the best option for improved accuracy, especially when the diagnostic laboratory only uses an automated system or oxacillin disk diffusion test. Combination of these methods with others presented almost 100% sensitivity and specificity in our study.
Collapse
Affiliation(s)
- Thais Dias Lemos Kaiser
- Laboratório de Resistência Bacteriana, Departamento Patologia, Universidade Federal do Espírito Santo, Vitória, ES, Brazil
| | | | | | | | | | | |
Collapse
|
12
|
Comparison of phenotypic methods in predicting methicillin resistance in coagulase-negative Staphylococcus (CoNS) from animals. Res Vet Sci 2010; 90:23-5. [PMID: 20538309 DOI: 10.1016/j.rvsc.2010.05.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 05/11/2010] [Accepted: 05/15/2010] [Indexed: 11/22/2022]
Abstract
Phenotypic detection of methicillin resistance in coagulase-negative Staphylococcus (CoNS) of animal origin has been challenging due to the heterogeneous expression of mecA. To compare different phenotypic methods in predicting the mecA presence in CoNS, a total of 87 CoNS isolates from agricultural animals were analyzed in this study by agar dilution, disk diffusion, and broth microdilution. mecA was present in 81 CoNS isolates. Broth microdilution demonstrated the highest sensitivity of 100% in predicting the mecA presence, followed by 72.8% by agar dilution and 70.4% by disk diffusion. The results indicate that broth microdilution may be more suitable for predicting the presence of mecA in CoNS from animals than the other two methods, although staphylococcal species may also be a factor affecting the sensitivities of the methods as the top three staphylococcal species in this study were Staphylococcus lentus, Staphylococcus sciuri, and Staphylococcus xylosus (a total of 75 of 87).
Collapse
|
13
|
Laboratory and clinical characteristics of Staphylococcus lugdunensis prosthetic joint infections. J Clin Microbiol 2010; 48:1600-3. [PMID: 20181900 DOI: 10.1128/jcm.01769-09] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus lugdunensis is a coagulase-negative staphylococcus that has several similarities to Staphylococcus aureus. S. lugdunensis is increasingly being recognized as a cause of prosthetic joint infection (PJI). The goal of the present retrospective cohort study was to determine the laboratory and clinical characteristics of S. lugdunensis PJIs seen at the Mayo Clinic in Rochester, MN, between 1 January 1998 and 31 December 2007. Kaplan-Meier survival methods and Wilcoxon sum-rank analysis were used to determine the cumulative incidence of treatment success and assess subset comparisons. There were 28 episodes of S. lugdunensis PJIs in 22 patients; half of those patients were females. Twenty-five episodes (89%) involved the prosthetic knee, while 3 (11%) involved the hip. Nine patients (32%) had an underlying urogenital abnormality. Among the 28 isolates in this study tested by agar dilution, 24 of 28 (86%) were oxacillin susceptible. Twenty of the 21 tested isolates (95%) lacked mecA, and 6 (27%) of the 22 isolates tested produced beta-lactamase. The median durations of parenteral beta-lactam therapy and vancomycin therapy were 38 days (range, 23 to 42 days) and 39 days (range, 12 to 60 days), respectively. The cumulative incidences of freedom from treatment failure (standard deviations) at 2 years were 92% (+/-7%) and 76% (+/-12%) for episodes treated with a parenteral beta-lactam and vancomycin, respectively (P=0.015). S. lugdunensis is increasingly being recognized as a cause of PJIs. The majority of the isolates lacked mecA. Episodes treated with a parenteral beta-lactam antibiotic appear to have a more favorable outcome than those treated with parenteral vancomycin.
Collapse
|
14
|
Abstract
This article familiarizes the clinician with the principles of bacterial susceptibility testing and reporting to facilitate communication with the clinical microbiology laboratory. As resistance continues to emerge among a wide range of clinically relevant bacteria, the complexity of this communication increases. This updated version provides an overview of the important susceptibility concerns for most commonly isolated bacterial pathogens.
Collapse
|
15
|
Comparison of the BD Phoenix system with the cefoxitin disk diffusion test for detection of methicillin resistance in Staphylococcus aureus and coagulase-negative staphylococci. J Clin Microbiol 2009; 47:2288-91. [PMID: 19439535 DOI: 10.1128/jcm.02431-08] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The BD Phoenix system was compared to the cefoxitin disk diffusion test for detection of methicillin (meticillin) resistance in 1,066 Staphylococcus aureus and 1,121 coagulase-negative staphylococcus (CoNS) clinical isolates. The sensitivity for Phoenix was 100%. The specificities were 99.86% for S. aureus and 88.4% for CoNS.
Collapse
|
16
|
Diab M, El-Damarawy M, Shemis M. Rapid identification of methicillin-resistant staphylococci bacteremia among intensive care unit patients. MEDSCAPE JOURNAL OF MEDICINE 2008; 10:126. [PMID: 18596947 PMCID: PMC2438486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Staphylococci represent the most commonly encountered blood culture isolates. With the spread of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCoNS) in hospitals, rapid and reliable methods for their detection are warranted in order to provide choice of appropriate antimicrobial therapy. This study evaluated 4 rapid methods directly from positive blood cultures in parallel with each other (on the same day) for identification of methicillin-resistant staphylococcal isolates, in addition to antimicrobial susceptibility testing (AST), to compare the workflow for each test and to reduce the turnaround time (TAT) in order to be presented as practical applications in our microbiology laboratory. A total of 56 bacteremic patients' blood cultures with Gram stains showing gram-positive cocci (GPC) in clusters were included. The following direct assays were evaluated: direct tube coagulase (DTC) test, analytical profile index (API)-Staph kit for species identification coupled with antimicrobial susceptibility testing (AST), latex agglutination for detection of PBP2a (PBP2a LA Assay), and cefoxitin disk diffusion assay. The direct results were compared with results obtained with isolated colonies using standard methods as well as detection of the mecA gene by PCR. DTC and API-staph exhibited sensitivities of 96% and 96.8% and specificity of 100% for direct identification of staphylococcal isolates. Both PBP2a LA and cefoxitin DD assays exhibited sensitivity of 100% for detection of both MRSA and MRCoNS and specificities of 100% and 75% (PBP2a assay) and 90% and 100% (cefoxitin DD) for identification of methicillin-sensitive isolates, respectively. For direct antimicrobial susceptibility testing (DAST), the overall error rate was 1.11%. In conclusion, direct identification and susceptibility testing by any of these assays yielded acceptable performance and timely results - 24 hours earlier than routine subculture - and can be easily incorporated into routine processing of positive blood cultures to improve the outcomes for the patient and the costs to hospitals. Therefore, it is recommended to use the method with high sensitivity and the shortest TAT.
Collapse
Affiliation(s)
- Manal Diab
- Medical Microbiology and Immunology, Cairo University, Guiza, Egypt.
| | | | | |
Collapse
|