Sputum Bacteriology And In-Vitro Antibiotic Susceptibility In Hospitalized Patients With Community Acquired Pneumonia In A State Tertiary - Referral Hospital – A Retrospective Study

Introduction: To review the sputum bacteriology and itsin-vitro antibiotic susceptibility in patients hospitalizedwith community-acquired pneumonia (CAP) in a statetertiary-referral Hospital (Penang hospital, Malaysia) inorder to determine the most appropriate empiricantibiotics.Methods: From September 2006 to May 2007,68 immunocompetent adult patients [mean age: 52years (range 16-89); 69% male] admitted to respiratorywards for CAP with positive sputum isolates within 48hours of admission were retrospectively identified andreviewed.Results: 62 isolates were Gram(-) bacilli (91%) &6 were Gram(+) cocci (9%). The two commonestpathogens isolated were Pseudomonas aeruginosa(n=20) and Klebsiella pneumoniae (n=19)together constituted 57% of all positive isolates.Among the Pseudomonas isolates, 84.2% were fullysensitive to cefoperazone and cefoperazon/sulbactam;95% to ceftazidime, cefepime, piperacillin/tazobactam,ciprofloxacin and amikacin, and 100% to gentamycin,netilmycin, imipenem and meropenem. Among theKlebsiella isolates, 5.3% were fully sensitive toampicillin; 84.2% to amoxicillin, ampicllin/sulbactam,cefuroxime and ceftriazone; 89.5% to piperacillin/tazobactam; 93.3% to cefoperazon/sulbactam and 100%sensitive to ceftazidime, cefepime, ciprofloxacin,all aminoglycosides and carbopenems.Conclusion: In view of the high prevalence ofrespiratory Pseudomonas aeruginosa, ampicillin/sulbactam, currently the most prescribed antibiotic totreat CAP in our respiratory wards, may not be the mostappropriate empiric choice. Higher generationcephalosporins with or without beta-lactamaseinhibitors, ciprofloxacin or carbapenem may be themore appropriate choices. The lack of information onpatients’ premorbidities such as recent hospitalizationand prior antibiotic exposure, limits the interpretationof our findings and may have biased our results towardshigher rates of Gram negative organisms.