A lack of standardization of environmental monitoring techniques for Legionella spp. complicates the interpretation of results and comparisons of results from different institutions. A comparative assessment of techniques recommended by the Centers for Disease Control and Prevention, the Hygiene Institute (Graz, Austria), and our laboratory was performed. Variables investigated were sampling method (swabbing and collection of water samples [250 ml] before and after swabbing), method of concentration (none, filtration, and centrifugation), acid buffer treatment (no acid treatment, treatment for 3 min, and treatment for 15 min), and choice of medium (five formulations of buffered charcoal yeast extract agar with glycine, vancomycin, polymyxin B, anisomycin, or cycloheximide). Thirty-three sites in seven hospital buildings were studied. Recovery by swab correlated with recovery from water after swabbing (P < 0.05). However, the quantity of Legionella spp. recovered from swab specimens (mean, 3.0 ؋ 10 4 CFU per swab) was greater than that recovered from water (mean, 4.7 ؋ 10 3 CFU/250 ml). Filtration resulted in recovery rates (mean, 5.2 ؋ 10 3 CFU/250 ml) higher than those by centrifugation (mean, 2.3 ؋ 10 3 CFU/250 ml). Three minutes of acid buffer treatment to reduce overgrowth by commensal flora did not improve selectivity or sensitivity for Legionella spp. if glycine-containing selective media were used. Fifteen minutes of acid buffer treatment reduced recovery compared with that after a 3-min treatment. All glycine-containing media tested effectively inhibited background flora, but one selective medium containing dyes, glycine, vancomycin, and polymyxin B (DGVP) resulted in the greatest quantitative recovery of Legionella pneumophila. Use of buffered charcoal yeast extract agar and the acid buffer treatment gave the greatest recovery of non-pneumophila species. A standardized protocol with an emphasis on the culturing of swab samples is presented.

Staphylococcus aureus is one of the leading microorganisms responsible for nosocomial infection in paediatrics. This study evaluated the incidence and antibiotic sensitivity patterns of haemolytic strains of S. aureus isolated from the environments of paediatric wards of Corner Stone Hospital (CSH), Osun State Hospital (OSH), and Emmanuel Hospital (EH), Osogbo. A total of 263 bacterial isolates were obtained from the hospitals. They were distributed as follows: 21.67%, 52.47% and 14.45% from CSH, OSH and EH respectively. S. aureus was predominant on the floor (47.15%) while the least was found in pillow (15.59%) in the hospitals. Sixty five (65) of the isolates were haemolytic and the distributions were 41.54%, 35.39% and 23.08% from CSH, OSH and EH respectively. The results showed that there were significant difference (p≤0.05) between the incidence of S. aureus and the location of the sampling. The antibiotic patterns shows that the isolates exhibited more susceptibility towards Gentamicin (100%) while the isolates exhibited more resistance towards Ampicillin (91.3%). The incidence of haemolytic and antibiotic resistant strain from locations where patients, health care personnel and workers have regular contact with represent a public health threat, therefore, safety measures to prevent nosocomial infections within the hospital environment should be put in place.