Conjunctival bacterial flora and their antibiotic sensitivity among patients scheduled for cataract surgery in a tertiary hospital in south-east Nigeria.

PURPOSE: To determine the pre-operative conjunctival bacteria flora and their antibiotic susceptibility among patients scheduled for cataract surgery. METHODS: A descriptive, cross-sectional, hospital-based study design was adopted. It involved 104 consecutive, consented patients scheduled for cataract surgery at the University of Nigeria Teaching Hospital Enugu, from June to September 2017. The participants' socio-demographic characteristics, medical, and social history were obtained through interviewer-administered questionnaire. Conjunctival swab was obtained from the inferior fornix of the eye scheduled for cataract surgery using sterile swab stick and transported to medical laboratory for analysis. Susceptibility tests were carried out on the representatives of different groups of available antibiotics. Data was analyzed using the SPSS version 23. RESULT: The participants were mainly females (64.4%), married, and farmers, with at least primary school education and a mean age of 64 ± 2SD years. The conjunctival swab bacteria isolation rate was 36.5%. Gram-positive bacteria accounted for 73.7% of the total isolates. Coagulase-negative Staphylococcus (34.2%) was the most frequently isolated bacteria. Gentamicin, ofloxacin, and polymycin B (76%) were the most efficacious antibiotics followed by moxifloxacin and tobramycin (68%) on all the isolates. Ofloxacin (82%) was the most sensitive to Gram positive while gentamicin (90%) was for Gram-negative bacteria. CONCLUSION: In Enugu, the most common pre-operative conjunctival bacteria isolated were Coagulase-negative Staphylococcus with varied antibiotic sensitivity. Routine prophylaxis with gentamicin and ofloxacin is therefore advised to forestall the dreaded post-operative endophthalmitis.

Antibiotic resistance in conjunctival and enteric bacterial flora in raptors housed in a zoological garden.

Antimicrobial resistance (AMR) in a wide range of infectious agents is a growing public health threat. Birds of prey are considered indicators of the presence of AMR bacteria in their ecosystem because of their predatory behaviour. Only few data are reported in the literature on AMR strains isolated from animals housed in zoos and none about AMR in raptors housed in zoological gardens. This study investigated the antibiotic sensitivity profile of the isolates obtained from the conjunctival and cloacal bacterial flora of 14 healthy birds of prey, 6 Accipitriformes, 3 Falconiformes and 5 Strigiformes, housed in an Italian zoological garden. Staphylococcus spp. was isolated from 50% of the conjunctival swabs, with S. xylosus as the most common species. From cloacal swabs, Escherichia coli was cultured from all animals, while Klebsiella spp. and Proteus spp. were isolated from a smaller number of birds. Worthy of note is the isolation of Escherichia fergusonii and Serratia odorifera, rarely isolated from raptors. Staphylococci were also isolated. All the isolates were multidrug resistant (MDR). To the author's knowledge, this is the first report regarding the presence of MDR strains within raptors housed in a zoological garden. Since resistance genes can be transferred to other pathogenic bacteria, this represents a potential hazard for the emergence of new MDR pathogens. In conclusion, the obtained data could be useful for ex-situ conservation programmes aimed to preserve the health of the endangered species housed in a zoo.

Microbiota conjuntival en el preoperatorio de pacientes que se someterán a cirugía de cataratas / Microbial flora isolated from patient's conjunctiva previous to cataract surgery

Background. Endophtalmitis post cataract surgery is one of most feared and devastating complications resulting in serious consequences and an uncertain visual prognosis. Antimicrobial prophylaxis against endophtalmitis must be based on the best knowledge of conjuntival microbiota. Objective: To establish microbiological basis for the best antibiotic prophylaxis to prevent endophthalmitis in cataract surgery. Materials and Methods: A descriptive, cross-sectional, prospective study. A preoperative conjunctival sample was taken from the lower fornix of 118 pacients, sowing it immediately in culture media. Identification of growing colonies and susceptibility testing were performed by manual or automated methods. Results: 106 (89.8%) of 118 preoperative cultures were positive. 159 bacteria were isolated in single or mixed flora, with 95% of Gram positive organisms. Staphylococci represented 76.1% of isolated bacteria, with 82.6% of coagulase-negative staphylococci (SCN) and 17.4% of Staphylococcus aureus. Forty two percent of SCN and 38% of S. aureus were methicillin resistan; both groups showed high susceptibility to tobramycin and fourth-generation fluoroquinolones. Conclusions: we recommend the use of topical tobramycin as pre-operative antimicrobial prophylaxis associated with povidone-iodine antisepsis. A fourth-generation quinolone is recommended when there is risk of infection.

Introducción: La endoftalmitis post-cirugía de cataratas es una de las complicaciones post-operatorias más temidas y devastadoras, pudiendo ocasionar secuelas graves, con un pronóstico visual incierto. La profilaxis antimicrobiana de esta complicación debe basarse en el conocimiento acabado de la microbiota presente en el territorio conjuntival. Objetivo: Establecer bases microbiológicas para una mejor profilaxis antimicrobiana de la endoftalmitis en cirugía de cataratas. Materiales y Métodos: Estudio descriptivo, de corte transversal, prospectivo. A 118 pacientes se les tomó muestra conjuntival pre-operatoria del fondo de saco inferior, sembrándola de inmediato en medios de cultivo. Las colonias desarrolladas se identificaron por métodos manuales y método de microdilución y difusión en disco. Resultados: De 118 cultivos pre-operatorios, 106 (89,8%) desarrollaron colonias bacterianas. Se aislaron 159 bacterias conjuntivales como especie única o cultivo mixta, siendo 95% grampositivas. El género Staphylococcus representó 76,1% del total de bacterias aisladas, siendo 82,6% Staphylococcus coagulasa negativa (SCN) y 17,4% Staphylococcus aureus. El 42% de los SCN y 38% de S. aureus presentaron resistencia a meticilina, presentando ambos buena susceptibilidad a tobramicina y fluoroquinolonas de cuarta generación. Conclusiones: Considerando nuestros resultados, recomendaríamos a nuestros pacientes tobramicina tópica como antibioprofilaxis, asociada a povidona yodada como antiséptico. Una quinolona de cuarta generación podría usarse cuando existan factores de riesgo de infección.

[Spectrum and susceptibility of preoperative conjunctival bacteria]. / Espectro y susceptibilidad de las bacterias conjuntivales preoperatorias.

PURPOSE: To describe the conjunctival bacterial spectrum of our patients undergoing intraocular surgery and their antibiotic sensitivity during the study period. METHODS: A retrospective study of preoperative conjunctival culture of patients consecutively scheduled for intraocular surgery from 21 February 2011 to 1 April 2013. Specimens were directly seeded onto blood-agar and MacConkey-agar (aerobiosis incubation, 2 days), and on chocolate-agar (6% CO2 incubation, 7 days). The identified bacteria were divided into 3 groups according to their origin; the bacteria susceptibility tests were performed on those more pathogenic and on some of the less pathogenic when more than 5 colonies were isolated. The sensitivity of the exigent growing bacteria was obtained with disk diffusion technique, and for of the non-exigent bacteria by determining their minimum inhibitory concentration. The Epidat 3.1 program was used for statistical calculations. RESULTS: A total of 13,203 bacteria were identified in 6,051 cultures, with 88.7% being typical colonizers of conjunctiva (group 1), 8.8% typical of airways (group 2), and the remaining 2.5% of undetermined origin (group 3). 530 cultures (8.8%) were sterile. The sensitivity of group 1 was: 99% vancomycin, 95% rifampicin, 87% chloramphenicol, 76% tetracycline. Levels of co-trimoxazole, aminoglycosides, quinolones, ß-lactams and macrolides decreased since 2007. The group 2 was very sensitive to chloramphenicol, cefuroxime, rifampicin, ciprofloxacin and amoxicillin/clavulanate. In group 3, to levofloxacin 93%, ciprofloxacin 89%, tobramycin 76%, but ceftazidime 53% and cefuroxime 29% decreased. CONCLUSIONS: None of the tested antibiotics could eradicate all possible conjunctival bacteria. Bacteria living permanently on the conjunctiva (group 1) have achieved higher resistance than the eventual colonizers.