title: Increasing frequency of gram-positive cocci and gram-negative multidrug-resistant bacteria in spontaneous bacterial peritonitis.
abstract: BACKGROUND
  Spontaneous bacterial peritonitis (SBP) is historically caused by Gram-negative bacteria (GNB) almost exclusively Enterobacteriaceae. Recently, an increasing rate of infections with Gram-positive cocci (GPC) and multidrug-resistant (MDR) microorganisms was demonstrated.
  
  
  OBJECTIVE
  To assess possible recent changes of the bacteria causing SBP in cirrhotic patients.
  
  
  METHODS
  We retrospectively recorded 47 cases (66% males) during a 4-year-period (2008-2011).
  
  
  RESULTS
  Twenty-eight (60%) patients had healthcare-associated infections while 15 (32%) received prophylactic quinolone treatment. GPC were found to be the most frequent cause (55%). The most prevalent organisms in a descending order were Streptococcus spp (n = 10), Enterococcus spp (n = 9), Escherichia coli (n = 8), Klebsiella pneumonia (n = 5), methicillin-sensitive Staphylococcus aureus (n = 4) and coagulase-negative Staphylococcus spp (n = 3). Nine of the isolated bacteria (19%) were MDR, including carbapenemase-producing K. pneumonia (n = 4), followed by extended-spectrum beta-lactamase-producing E. coli (n = 3) and Pseudomonas aeruginosa (n = 2). MDR bacteria were more frequently isolated in healthcare-associated than in community-acquired infections (100% vs 50%, P = 0.006), in patients receiving long-term quinolone prophylaxis (67% vs 24%, P = 0.013) and in those with advanced liver disease as suggested by higher MELD score (28 vs 19, P = 0.012). More infections with GNB than GPC were healthcare-associated (81% vs 42%, P = 0.007). Third-generation cephalosporin resistance was observed in 49% and quinolone resistance in 47%.
  
  
  CONCLUSIONS
  GPC were the most frequent bacteria in culture-positive SBP and a variety of drug-resistant microorganisms have emerged. As a result of high rates of resistance in currently recommended therapy and prophylaxis, the choice of optimal antibiotic therapy is vital in the individual patient.
authors.affiliation: 2nd Department of Medicine, University of Athens Medical School, Athens, Greece. alexopou@ath.forthnet.gr
authors.forename: Alexandra
authors.initials: A
authors.lastname: Alexopoulou
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Papadopoulos
authors.forename: Dimitrios G
authors.initials: DG
authors.lastname: Eliopoulos
authors.forename: Apostolia
authors.initials: A
authors.lastname: Alexaki
authors.forename: Athanasia
authors.initials: A
authors.lastname: Tsiriga
authors.forename: Marina
authors.initials: M
authors.lastname: Toutouza
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Pectasides
mesh_terms: D000368:Aged; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006090:Gram-Negative Bacteria; D006095:Gram-Positive Cocci; D006115:Greece / Q000453:epidemiology; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications*; D008297:Male; D008875:Middle Aged; D010538:Peritonitis / Q000453:epidemiology* / Q000209:etiology* / Q000382:microbiology*; D015995:Prevalence; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
keywords: ESBL-producing E. coli; carbapamenase-producing K. pneumonia; multidrug-resistant bacteria; quinolone resistance; spontaneous bacterial peritonitis; third-generation cephalosporin resistance