Pyocine-typing of hospital strains of Pseudomonas pyocyanea

Darrell, J. H.; Wahba, A. H.

doi:10.1136/jcp.17.3.236

Cited by 92 publications

(46 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Assay for the pyocin sensitivity was carried out by the pyocin typing method of Darrell and Wahba [5] using neutral broth agar as the typing medium. Strains PI-111 and P16 were used as a pyocin A and a pyocin S pyocinogenic strain, respectively.…”

Section: Methodsmentioning

confidence: 99%

Correlation between pyocin‐sensitivity and 2‐amino sugar composition of Pseudomonas aeruginosa

Suzuki

1974

FEBS Letters

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Correlation between pyocin‐sensitivity and 2‐amino sugar composition of Pseudomonas aeruginosa

Suzuki

1974

FEBS Letters

View full text Add to dashboard Cite

“…In the initial studies on about 4000 isolates, the method used was a modification of a pyocine typing method (Darrell and Wahba, 1964) in which test strains were inoculated as a heavy streak across the diameter of a glass petri dish containing blood-agar-base medium. This plate was then incubated for 24 h, after which the growth was removed by scraping with a microscope slide and the plate was exposed to chloroform vapour for 10 min.…”

Section: Methodsmentioning

confidence: 99%

Carriage of inhibitor-producing organisms on human skin

Noble¹,

Willie²

1980

Journal of Medical Microbiology

View full text Add to dashboard Cite

SELWYN (1975) described the carriage of antibiotic-producing organisms on human skin and showed how they might protect the carrier against colonisation with potential pathogens such as Staphylococcus aureus. Subsequent work by Selwyn and his colleagues (Marsh and Selwyn, 1977a and b;Milyani and Selwyn, 1978) has shown that these antibiotic producers can restrict the growth of susceptible strains in vitro. This paper reports a study of the carriage, in patients with skin disease, of "antibiotic"-producing cocci with an activity against S. aureus. MATERIALS AND METHODSSamples for bacterial culture were taken from the nose, the chest, the perineum and one or more lesions of patients admitted to the Inpatient Department of St John's Hospital for Diseases of the Skin; cotton-tipped swabs moistened with broth were used. When S. aureus was isolated from a skin lesion the opinion of a clinician, usually the senior house officer, was sought on whether the lesion was clinically infected or only colonised; these opinions were recorded. The swabs were inoculated on to Blood Agar Base (Oxoid CM55) used as a 'nutrient' agar and the plates were incubated aerobically for 24 h at 37°C and left on the bench for a further 24 h at ambient temperature. A semi-quantitative assessment was made of each colony type present.Representatives of all colony types were subcultured on to blood-agar-base plates under a serial code number and examined for production of inhibitors. In the initial studies on about 4000 isolates, the method used was a modification of a pyocine typing method (Darrell and Wahba, 1964) in which test strains were inoculated as a heavy streak across the diameter of a glass petri dish containing blood-agar-base medium. This plate was then incubated for 24 h, after which the growth was removed by scraping with a microscope slide and the plate was exposed to chloroform vapour for 10 min. After exposure to air to permit evaporation of residual chloroform, four indicator strains were inoculated at right angles to the site of the original culture. The plates were then reincubated for 24 h at 37°C. Antibiotic production was indicated by a failure of growth in the area from which the test strain had been removed.Another 1300 isolates were tested by a modification of thismethod in which, after removal of the test-isolate growth with a glass microscope slide, any remaining cells were spread over the surface of the medium with a cotton tipped swab ('Q-tip') moistened in broth. The plate was then exposed to ultraviolet light for 20 min. to kill remaining cells; four indicator strains were then applied as previously described.The indicator strains used were S. aureus PS80, the original epidemic strain which remains virulent for mice and is used for propagating phage 80; S. aureus PS 42E, the propagating strain for phage 42E; S. aureus Wood 46, the standard a-haemolysin producer; and Micrococcus luteus 27B, a wild-type isolate from a patient. RESULTSFrom 292 patients, 5282 strains were tested. Inhibitor producers active against S. ...

show abstract

“…The human pathogen Pseudornonas aeruginosa (Pyocyanea) is found frequently in hospital-acquired infections (Darrell & Wahba, 1964 ;Bassett, Thompson & Page, 1965;. Certain sites such as the urinary tract and burnt skin are particularly susceptible, as are patients with lowered resistance and children.…”

Section: Introductionmentioning

confidence: 99%

Studies on the Virulence of Hospital Strains of Pseudomonas aeruginosa

Klyhn¹,

Gorrill²

1967

Journal of General Microbiology

View full text Add to dashboard Cite

SUMMARYThe virulence of 36 strains of Pseudomonas aeruginosa was studied by intravenous injection into mice; the strains were found to fall into three broad groups, of high, medium and low virulence. This difference could not be related to any biochemical property studied, pyocine type nor antibiotic sensitivity pattern. It was found that 24 of the 30 strains of the high and medium virulence group produced large colonies on agar while 5 of the 6 strains of the low virulence group produced small colonies when plated under similar conditions. To test this observation a further series was collected and the strains were allocated to the high or low virulence category on colonial appearance. Mouse challenge with these fresh strains showed that the prediction was accurate. The large colony type had a faster growth rate on agar and in broth than the small. When a strain was grown in agar it was found to be more virulent than when harvested from broth (P = 0.02-0.01).Chromatography studies on slime derived from all three categories showed that they were apparently chemically similar. The amount of slime produced by a standard number of bacteria was measured for agar and broth grown cultures. The yields for the two media were approximately the same with large-colony forms. Small-colony forms produced similar amounts to the large forms on plates, but up to 15 times as much when grown in broth.The ability to kill mice was derived in part from early toxic death; the remainder died of renal disease. Study of the initiation of kidney infection showed that large-colony types were more successful in maintaining their numbers in the kidneys over the first 5 hr. Strains grown on nutrient agar did not give higher counts in the kidney than those from broth in the first 5 hr but after 24 hr they grew faster, infected more kidneys and killed more mice.

show abstract

Pyocine-typing of hospital strains of Pseudomonas pyocyanea

Cited by 92 publications

References 27 publications

Correlation between pyocin‐sensitivity and 2‐amino sugar composition of Pseudomonas aeruginosa

Correlation between pyocin‐sensitivity and 2‐amino sugar composition of Pseudomonas aeruginosa

Carriage of inhibitor-producing organisms on human skin

Studies on the Virulence of Hospital Strains of Pseudomonas aeruginosa

Contact Info

Product

Resources

About