Restricted accessResearch articleFirst published online 2022-05
Evaluation of Methicillin-Resistant Staphylococcus aureus Carriage in the Elderly in Portugal Using Selective Enrichment Followed by Quantitative Real-Time PCR
The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals in Portugal is worrisome and among the highest in Europe. Surprisingly, MRSA prevalence in the community was described as very low (<2%) based on studies that used classical culture-based methods (CCBM). We investigated whether the apparent limited spread of MRSA in the community in Portugal might result from low sensitivity of CCBM. Nasopharyngeal- and oropharyngeal-paired samples obtained from senior adults living in nursing (n = 299) or family homes (n = 300) previously characterized by CCBM were reanalyzed. Samples were inoculated in a semi-selective enrichment medium, and those showing visible growth were evaluated by qPCR targeting nuc, mecA, and mecC genes (SSE+qPCR). By SSE+qPCR, 34 of the 1,198 (2.8%) samples were MRSA positive compared with 21 (1.8%) by CCBM. SSE+qPCR improved non-significantly detection of MRSA carriers from 5.4% to 8.0% (p = 0.12) in the nursing home collection, and from 0.3% to 1.7% (p = 0.13) in the family home collection. MRSA isolates belonged to three HA-MRSA clones widely disseminated in Portuguese hospitals. In conclusion, use of semi-selective medium combined with qPCR did not change the overall scenario previously described. In Portugal, MRSA circulation in the community among senior adults is low.
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References
1.
Wertheim, H.MellesF. D.C, VosM.C, et al.2005. The role of nasal carriage in Staphylococcus aureus infections. Lancet Infect. Dis. 5:751–762.
2.
Lowy, F.D. 1998. Staphylococcus aureus infections. N. Engl. J. Med. 339:520–532.
3.
Centers for Disease Control and Prevention (CDC). 1999. Four pediatric deaths from community-acquired methicillin-resistant Staphylococcus aureus - Minnesota and North Dakota, 1997–1999. JAMA, 282:1123–1125.
4.
UdoE.E., PearmanJ.W, and GrubbW.B.. 1993. Genetic analysis of community isolates of methicillin-resistant Staphylococcus aureus in Western Australia. J. Hosp. Infect. 25:97–108.
5.
Chambers, H.F. 2001. The changing epidemiology of staphylococcus aureus? Emerg. Infect. Dis. 7:178–182.
6.
European Centre for Disease Prevention and Control. 2020. Antimicrobial Resistance in the EU/EEA (EARS-Net)—Annual Epidemiological Report 2019. Stockholm, ECDC.
7.
DavidM.Z., and DaumR.S.. 2010. Community-associated methicillin-resistant Staphylococcus aureus: epidemiology and clinical consequences of an emerging epidemic. Clin. Microbiol. Rev. 23:616–687.
8.
MarcheseA., GualcoL., MaioliE., and DebbiaE.. 2009. Molecular analysis and susceptibility patterns of meticillin-resistant Staphylococcus aureus (MRSA) strains circulating in the community in the Ligurian area, a northern region of Italy: emergence of USA300 and EMRSA-15 clones. Int. J. Antimicrob. Agents, 34:424–428.
9.
HornerC., ParnellP., HallD., KearnsA., HeritageJ., and WilcoxM.. 2013. Meticillin-resistant Staphylococcus aureus in elderly residents of care homes: colonization rates and molecular epidemiology. J. Hosp. Infect. 83:212–218.
10.
TavaresA., MiragaiaM., RoloJ., CoelhoC., and de LencastreH.. 2013. High prevalence of hospital-associated methicillin-resistant Staphylococcus aureus in the community in Portugal: evidence for the blurring of community-hospital boundaries. Eur. J. Clin. Microbiol. Infect. Dis. 32:1269–1283.
11.
DiekemaD.J., RichterS.S, HeilmannK.P, et al.2014. Continued emergence of USA300 methicillin-resistant Staphylococcus aureus in the United States: results from a nationwide surveillance study. Infect. Control Hosp. Epidemiol. 35:285–292.
12.
BushK., LealJ., FathimaS., et al.2015. The molecular epidemiology of incident methicillin-resistant Staphylococcus aureus cases among hospitalized patients in Alberta, Canada: a retrospective cohort study. Antimicrob. Resist. Infect. Control. 4:35.
13.
DrougkaE., FokaA., LiakopoulosA., et al.2014. A 12-year survey of methicillin-resistant Staphylococcus aureus infections in Greece: ST80-IV epidemic? Clin. Microbiol. Infect. 20:O796–O803.
14.
FariaN.A., MiragaiaM., and de LencastreH.. 2013. Massive dissemination of methicillin resistant Staphylococcus aureus in bloodstream infections in a high MRSA prevalence country: establishment and diversification of EMRSA-15. Microb. Drug Resist. 19:483–490.
15.
Aires-de-SousaM., CorreiaB., and de LencastreH.. 2008. Changing patterns in frequency of recovery of five methicillin-resistant Staphylococcus aureus clones in Portuguese hospitals: surveillance over a 16-year period. J. Clin. Microbiol. 46:2912–2917.
16.
EspadinhaD., FariaN.A, MiragaiaM., LitoL.M, Melo-CristinoJ., and de LencastreH.. 2013. Extensive dissemination of methicillin-resistant Staphylococcus aureus (MRSA) between the hospital and the community in a country with a high prevalence of nosocomial MRSA. PLoS One, 8:e59960.
17.
AmorimM.L., FariaN.A, OliveiraD.C, et al. 2007. Changes in the clonal nature and antibiotic resistance profiles of methicillin-resistant Staphylococcus aureus isolates associated with spread of the EMRSA-15 clone in a tertiary care Portuguese hospital. J. Clin. Microbiol. 45:2881–2888.
18.
AlmeidaS.T., NunesS., PauloA.C, FariaN.A, de LencastreH., and Sá-LeãoR.. 2015. Prevalence, risk factors, and epidemiology of methicillin-resistant Staphylococcus aureus carried by adults over 60years of age. Eur. J. Clin. Microbiol. Infect. Dis. 34:593–600.
19.
TavaresD.A., Sá-LeãoR., MiragaiaM., and de LencastreH.. 2010. Large screening of CA-MRSA among Staphylococcus aureus colonizing healthy young children living in two areas (urban and rural) of Portugal. BMC Infect. Dis. 10:110.
20.
Sá-LeãoR., SanchesI.S, CoutoI., AlvesC.R, and de LencastreH.. 2001. Low prevalence of methicillin-resistant strains among Staphylococcus aureus colonizing young and healthy members of the community in Portugal. Microb. Drug Resist. 7:237–245.
21.
Palavecino, EL. 2014. Rapid methods for detection of MRSA in clinical specimens. In: J. Yinduo J (ed.), Methicillin-resistant Staphylococcus aureus (MRSA) protocols. 2nd ed. Springer Science+Business Media, New York Heidelberg Dordrecht, London, pp. 71–83.
22.
EkenbergC., BoyeK., SchønningK., WesthH., and LisbyG.. 2014. Detection of mecC methicillin-resistant Staphylococcus aureus with a semi-selective enrichment broth. J. Antimicrob. Chemother. 69:2864.
23.
LeeS., ParkY.J, ParkK.G, et al.2013. Comparative evaluation of three chromogenic media combined with broth enrichment and the real-time PCR-based Xpert MRSA assay for screening of methicillin-resistant Staphylococcus aureus in nasal swabs. Ann. Lab. Med. 33:255–260.
24.
EspyM.J., UhlJ.R, SloanL.M, et al.2006. Real-time PCR in clinical microbiology: applications for routine laboratory testing. Clin. Microbiol. Rev. 19:165–256.
25.
WolkD.M., PictonE., JohnsonD., et al.2009. Multicenter evaluation of the Cepheid Xpert methicillin-resistant Staphylococcus aureus (MRSA) test as a rapid screening method for detection of MRSA in nares. J. Clin. Microbiol. 47:758–764.
26.
WattJ.P., O'BrienK.L, KatzS., et al.2004. Nasopharyngeal versus oropharyngeal sampling for detection of pneumococcal carriage in adults. J. Clin. Microbiol. 42:4974–4976.
27.
Clinical and Laboratory Standards Institute (CLSI). 2009. Performance Standards for Antimicrobial Susceptibility Testing, Aproved Standard. 10th ed. M02-A12. CLSI, Wayne, PA, USA.
28.
MilheiriçoC., OliveiraD.C, and de LencastreH.. 2007. Update to the multiplex PCR strategy for assignment of mec element types in Staphylococcus aureus. Antimicrob. Agents Chemother. 51:3374–3377.
29.
BöcherS., MiddendorfB., WesthH., et al.2010. Semi-selective broth improves screening for methicillin-resistant Staphylococcus aureus. J. Antimicrob. Chemother. 65:717–720.
30.
NygaardT.K., PallisterK.B, RuzevichP., GriffithS., VuongC., and VoyichJ.M.. 2010. Saer binds a consensus sequence within virulence gene promoters to advance USA300 pathogenesis. J. Infect. Dis. 201:241–254.
31.
BartelsM.D, KnudsenD., WesthH., and SchønningK.. 2021. Evaluation of the hologic panther fusion MRSA assay for the detection of MRSA in ESWAB specimens obtained from nose, throat, and perineum. Eur. J. Clin. Microbiol. Infect. Dis. 40:2177–2183.
32.
Core Team. 2015. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing. Available at https://www.R-project.org/.
33.
ZanellaR.C., BrandileoneM.C.C, AlmeidaS.C.G, et al.2019. Nasopharyngeal carriage of Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus in a Brazilian elderly cohort. PLoS One, 14:e0221525.
34.
ScerriJ., MoneckeS., and BorgM.A.. 2013. Prevalence and characteristics of community carriage of methicillin-resistant Staphylococcus aureus in Malta. J. Epidemiol. Glob. Health, 3:165–173.
35.
MainousIII, A.G., HuestonW.J, EverettC.J, and DiazV.A.. 2006. Nasal carriage of Staphylococcus aureus and methicillin-resistant S. aureus in the United States, 2001–2002. Ann. Fam. Med. 4:132–137.
36.
WangH.Y., KimS., KimJ., ParkS.D, UhY., and LeeH.. 2014. Multiplex real-time pcr assay for rapid detection of methicillin-resistant staphylococci directly from positive blood cultures. J. Clin. Microbiol. 52:1911–1920.
37.
KilicA., MuldrewK.L, TangY.W, and BasustaogluA.C.. 2010. Triplex real-time polymerase chain reaction assay for simultaneous detection of Staphylococcus aureus and coagulase-negative staphylococci and determination of methicillin resistance directly from positive blood culture bottles. Diagn. Microbiol. Infect. Dis. 66:349–355.
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