title: Longevity and gender as the risk factors of methicillin-resistant Staphylococcus aureus infections in southern Poland.
abstract: The proportion of older people among the general population has risen. Staphylococcus aureus (SA) constitutes a significant problem. Underlying disease and functional debility, predispose the older adult to staphylococcal carriage and infection, specially bloodstream infection and pneumonia.
  
  
  
  This is a retrospective cohort study of older patients with SA infections. We analyzed a database containing the results of laboratory cultures from patients treated in 2013 for SA infections and selected 613 hospitalized and non-hospitalized people aged ≥60 years.
  
  
  
  The prevalence of Methicillin-resistant SA (MRSA) were significantly different in categories of patients: from 14.1% in young old, 19.5% in old old and 26.7 in longevity. MRSA was significantly more frequently reported in cases of pneumonia, 40.4% of SA strains (p < 0.0001, OR 0.3, 95%CI 0.14-0.49). The nosocomial MRSA infections were more common in ICU departments: prevalence 36.8%, than in non-ICU departments: prevalence 17.3% (OR 2.8, 95%CI 1.06-7.34, p = 0.014). Bloodstream infections, which accounted for 6% of all infections, were more frequent in males (p = 0.0231, OR 2.25, 95%CI 1.098-4.604). The greatest increase in antibiotic resistance was related to trimethoprim/sulfamethoxazole (TMP/SXT), which increased to over 80% in the older study groups. All age groups demonstrated increased MIC90 values for glycopeptide and tigecycline. Although strains isolated from patients in all age groups remained sensitive to vancomycin, strains isolated from patients in the old-old and longevity groups demonstrated resistance to teicoplanin. The MIC90 for tigecycline was the highest in the group aged >90 years.
  
  
  
  MRSA constitutes a significant epidemiological problem in cases of hospital-treated pneumonia. The findings were similar for long-term-care facilities, where MRSA appears to affect male residents in particular, although there were fewer male residents than female residents. The low sensitivity to TMP/SXT of SA strains isolated from the oldest patients indicates potentially serious challenges pertaining to efficacious treatment of SA infections.
authors.affiliation: Department of Microbiology, Analytical and Microbiological Laboratory of Ruda Slaska, KORLAB NZOZ, Ruda Slaska, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Pomorska-Wesołowska
authors.affiliation: Chair of Microbiology, Faculty of Medicine, Jagiellonian University Medical College, 18 Czysta Street, 31-121, Krakow, Poland. a.rozanska@uj.edu.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Różańska
authors.affiliation: Chair of Microbiology, Faculty of Medicine, Jagiellonian University Medical College, 18 Czysta Street, 31-121, Krakow, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Natkaniec
authors.affiliation: Department of Internal Medicine and Gerontology, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Gryglewska
authors.affiliation: Faculty of Health and Medical Sciences, Andrzej Frycz-Modrzewski Krakow University, Krakow, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Szczypta
authors.affiliation: Department of Clinical Nursing Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Mirosława
authors.initials: M
authors.lastname: Dzikowska
authors.affiliation: Chair of Microbiology, Faculty of Medicine, Jagiellonian University Medical College, 18 Czysta Street, 31-121, Krakow, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Chmielarczyk
authors.affiliation: Chair of Microbiology, Faculty of Medicine, Jagiellonian University Medical College, 18 Czysta Street, 31-121, Krakow, Poland.
authors.forename: Jadwiga
authors.initials: J
authors.lastname: Wójkowska-Mach
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D003428:Cross Infection / Q000453:epidemiology; D005260:Female; D006801:Humans; D008134:Long-Term Care; D008136:Longevity; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus; D008875:Middle Aged; D011044:Poland / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D012737:Sex Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antibiotic resistance; Infection; Longevity; MRSA; Trimethoprim/sulfamethoxazole