Antibiotic susceptibility of staphylococci isolates from patients with chronic conjunctivitis: including associated factors and clinical evaluation.
OBJECTIVE
To determine species of staphylococci in chronic conjunctivitis, their antibiotic susceptibility pattern, patient treatments, clinical course, and clinical conditions.


METHODS
In this prospective study, 243 conjunctival cultures were taken from 191 patients with chronic conjunctivitis, we obtained staphylococci susceptibility patterns with E-test, and they were analyzed in coagulase-positive and negative. The minimum inhibitory concentration for 90% of isolates (MIC90) was determined for Staphylococcus aureus and Staphylococcus epidermidis. Additionally, clinical follow-up and associated factors of all patients were analyzed depending on methicillin resistance (MR) or susceptibility (MS) bacterial state.


RESULTS
One hundred and eight (44%) cultures were positive; 81 positive cultures were Gram-positive of which, 77 were staphylococci, 29 coagulase-positive with S. aureus as the most prevalent, 89% MS, and 11% MR. And 48 were coagulase-negative with S. epidermidis as the most isolated with 36% of MS and 64% of MR. Poor susceptibility was found in the staphylococcus coagulase-negative/MR group. Moxifloxacin and vancomycin show the best in vitro activity for all isolates. The MIC90 of moxifloxacin and vancomycin were 0.064/1.5, 0.64/3.0, and 1/3.0 for S. aureus-MS, S. epidermidis-MS, and S. epidermidis-MR, respectively. The most frequently associated factors found in patients with positive culture for staphylococcus were exposure to the health care system 23 (29.87%) of 77 patients and dry eye 23 (29.87%) of 77 patients. Both with a proportion of 3 in 10.


CONCLUSIONS
Coagulase-negative staphylococci were the most frequently isolated from the conjunctiva with 58.33% of MR; even though multiresistance was detected, their susceptibility to a fourth-generation fluoroquinolone, commonly used, such as moxifloxacin, was preserved.
Cornea and Refractive Surgery Unit, Vision Sana Research Group, Clínica de Oftalmología de Cali, Faculty of Medicine Pontificia Universidad Javeriana Cali , Cali, Colombia .
Claudia
C
Blanco
María Ximena
MX
Núñez
D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001372:Aza Compounds / Q000494:pharmacology; D002908:Chronic Disease; D003234:Conjunctivitis, Bacterial / Q000188:drug therapy / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D024841:Fluoroquinolones; D005500:Follow-Up Studies; D006801:Humans; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D000077266:Moxifloxacin; D011804:Quinolines / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology; D013210:Staphylococcus / Q000187:drug effects* / Q000302:isolation & purification; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000302:isolation & purification; D016896:Treatment Outcome; D014640:Vancomycin / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D014640:Vancomycin; D000077266:Moxifloxacin