Bacteria in a hospital nursery: laboratory and clinical studies

Abstract

SummaryTwo hundred and twenty-two infants and fifty-one staff were examined for carriage ofStaphylococcus pyogenesand Gram-negative bacilli, and the presence of these bacteria in the ward environment was also investigated. Staphylococci were phage-typed and tested for sensitivity to antibiotics. Assessment of clinical infection caused by these bacteria was made.Infant carriage ofStaphylococcus pyogeneswas maximal on the sixth day, 73·1 % of umbilical swabs yielding significant growth. Carriage of Gram-negative bacilli was maximal on the fifth day, 31·7% of umbilical swabs being positive. Where special nursing was enforced, i.e. premature baby unit, isolation of Gram-negative bacilli was very infrequent.The low nasal carriage of staphylococci seen in infants and nursing staff is attributed to traces of penicillinase-resistant penicillins in the ward air.Staphylococcus pyogeneswas recovered from 23 % of ward surfaces, and constituted 0·7% of the air-borne flora. In contrast, Gram-negative bacilli were recovered from 4·7 % of surfaces, and composed only 0·15% of the air-borne flora.Phage group I constituted 73·0, 44·9 and 41·2% of strains from infants, staff and ward environment respectively.Antibiograms were grouped into three categories, A, B and C. Category A (sensitive to chloramphenicol, erythromycin and methicillin but penicillin-resistant) composed 79·0% of infants' strains, being found mostly in group I, but was rare among staff strains.Of 54 specimens taken from 40 infants showing evidence of infection,Staphylococcus pyogeneswas isolated from 16, of which 14 were category A. Gram-negative bacilli were isolated 7 times. Only 21 infants required antibiotic therapy (9·3%) and none were infected with Gram-negative bacilli—this contrasts with the frequency of these bacilli in nursery infection today.Ward air is considered to be the maindepotofStaphylococcus pyogenes. Infant ‘dispersers’ are probably the principalsourceof the air-borne staphylococci. Infants and staff abstract from the air those staphylococci which become their colonizing strains. No transfer is thought to occur from the staff to the infants. Transmission of Gram-negative bacilli is similar in that the infants are the principal source and the air the maindepotof these bacteria. Nasal colonization by Gram-negative bacilli is low, this is possibly due to poor colonizing properties. Infant umbilical carriage almost certainly results from endogenous faecal spread.We are grateful to Dr J. C. Gould, Director, Central Microbiological Laboratories, Edinburgh, for his continued interest and advice, and to Mr J. C. Ferguson and Mrs M. M. Winton for skilled technical assistance. This study would not have been completed without the co-operation of Sisters McCartney and Struthers and their nursing staff.

Bacterial infection in the fetus and newborn.

“…Winton and Keay (1968) think otherwise, believing the ward air to be the main depot. Though the hands ofover 50% of the attendant staff of their newborn nursery yielded these organisms they showed that the main 'pattern' (a combination of predominant phage group isolated with most frequently occurring antibiotic sensitivity category) was different from that of the infants, though less frequently encountered patterns might be common to both.…”

Study of Oral, Nasal and Skin Flora in an Investigation on Hospital Infection

“…This contributes 30% of all isolates (table II). The increasing importance of gram-negative rods in hospital infections is a subject receiving much interest [1,2,3,4,7,13,14], and attention has been paid to the increasing prevalence of gram-negative bacteria in hospital en vironments [8,11,15], J o h a n so n et al [8] found a higher proportion of proteus and Serratia marcescens as compared to other gram-negative bac teria. Under the conditions of our study, the total of 439 potentially pathogenic bacteria was distributed evenly between the groups of surgery and internal medicine.…”

Descontaminação Quimico-Microbiológica Em Ambientes Hospitalares Por Meio De Purificador Iônico

“…Em berçários os Gram positivos patogênicos foram avaliados em 0,7 % da população anemófila e os Gram negativos pa togênicos em 0,15% (15) . É provável que com o aumento da preva lência das infecções hospitalares causadas por Gram negativos nestes últimos anos, a proporção de partículas aéreas contendo Gram ne gativos seja maior .…”