Methicillin resistance in Staphylococcus aureus with particular reference to Victorian strains.

There is controversy regarding methods employed for the detection of methicillin resistance in Staphylococcus aureus, and dispute whether infections caused by these organisms can be successfully treated with methicillin or similar antibiotic agents. Cell populations of methicillin-resistant Staph. aureus (MRSA) are heterogeneous with respect to the level of resistance expressed, but always contain a subpopulation of highly resistant cells which can neither be inhibited nor killed by beta-lactam antibiotic agents. Clinical experience confirms that in severe infections, particularly when host defences are imparied, the use of beta-lactam antibiotic agents to treat MRSA is associated with an unacceptably high failure rate. Current Victorian strains of MRSA are multiresistant. Thus vancomycin is the drug of choice for life-threatening infections, while the combination of fusidic acid either with flucloxacillin or with rifampicin is useful for infections of moderate severity.

Unconventional bacteria in urinary tract disease: Ureaplasma urealyticum.

Bladder-aspirate urine samples (N = 428) were cultured for the presence of fastidious microorganisms. These samples were obtained from 190 patients with urinary tract disease or symptoms suggesting infection of the urinary tract in whom standard bacteriologic investigation had failed to indicate bacterial infection. Ureaplasma urealyticum was recovered alone or in association with other microorganisms from the bladder urine of 75% of patients with reflux scarring and abnormal renal function. Ureaplasma organisms were localized to the upper urinary tract in 80% of patients with bladder counts greater than 10(3) colony-forming units per ml. The results indicate that microorganisms not conventionally associated with urinary tract infection are recoverable from the bladder urine of a high percentage of patients with so-called "sterile pyelonephritis," in which group of patients these microorganisms may contribute to progressive renal disease.

Oxolinic acid in the treatment of urinary tract infections.

Oxolinic acid was successfully used in eradicating bacteriuria in 86% of a highly selected group of 42 patients with chronic and recurrent urinary infections. Thirty-eight (92%) of patients had underlying renal abnormalities, 19 (45%) had impaired renal function. Emergence of resistant organisms in 3 patients (7%), and a high incidence of side effects necessitating withdrawal of treatment in 12 patients (29%), limit the usefulness of this agent to special situations. In patients with moderate and severe renal impairment, oxolinic acid achieves adequate urinary concentration, does not accumulate in the serum and is not nephrotoxic. The drug is safe and effective to use in patients with renal impairment.

The emergence of gentamicin-resistant klebsiellae in a large general hospital.

Between March and December, 1975, an outbreak of infection with gentamicin-resistant Klebsiella pneumoniae (klebsiella (Gmr)) occurred at the Royal Melbourne Hospital. The klebsiellae were considered to be causing significant infection in 24 of 42 patients harbouring the microorganism. Commonest culture sources were urine and sputum, all but one of the significant urinary infections being associated with indwelling bladder catheters. Antibiotic therapy had been given to 40 patients before the isolation of klebsiella (Gmr), and of these 22 had received gentamicin. Cross infection was a major factor in the outbreak, and control measures (to limit this aspect and curtail the usage of gentamicin) have prevented wider spread within the hospital; at the time of writing the microorganism had been eradicated from all but one of the infected patients. It was shown that klebsiella (Gmr) carry an R-factor capable of transferring gentamicin resistance. Of 22 isolates tested quantitatively, 20 were resistant to 10 mug/ml of gentamicin.

The need for three stool specimens in routine laboratory examinations for intestinal parasites.

This study was designed to test whether three sequential stool specimens are necessary for reliable detection of intestinal parasites in routine laboratory examinations. There were 175 patients in whom a single species of intestinal parasite or ova was identified on at least one occasion when three stool specimens were examined over a period of 14 days from the first recorded specimen. Examination of a first stool specimen detected parasites and/or ova in 102/175 patients (58.3%); examination of a second specimen identified an additional 36 positive patients (20.6%) and examination of a third specimen yielded a final 37 previously undetected patients (21.1%). These findings indicate that at least three stool specimens should be examined to confirm the presence of intestinal parasites. Even with such practice, it is not possible to guarantee that there is no infestation, but examination of fewer specimens would run a definite risk of false negative results.

Drug trials: treatment of urinary tract infection with multiple-dose intramuscular administration of cephamandole.

Therapy with cephamandole (1.0 g, every eight hours) for five days was effective in eliminating cephamandole-sensitive microorganisms from the urinary tract. A 75% cure rate was achieved in a group of 20 patients, 45% of whom had abnormalities of the urinary tract. Local pain (despite addition of lignocaine) was sufficiently prolonged and severe to make multiple-dose intramuscular administration unacceptable. No other toxic effects were encountered.

Epidemic of hospital-acquired infection due to methicillin-resistant Staphylococcus aureus in major Victorian hospitals.

During 1979, the Victorian Health Commission received reports of a rising proportion of methicillin-resistant Staphylococcus aureus (MRSA) isolates from an increasing number of institutions. At least 31 metropolitan hospitals were involved, and six of these reported MRSA totaling between 20% and 40% of all Staph. aureus isolates. Since that time, the problem has continued. In some university teaching hospitals, strains of MRSA now cause from 200 to 300 new cases of hospital-acquired infection each year. Sepsis occurs mainly in patients who underwent surgery, premature neonates and in the immunocompromised or debilitated patients. The organism involved is multiresistant. Recent isolates show increasing resistance, particularly against gentamicin, chloramphenicol and, more lately, fusidic acid and rifampicin. Only vancomycin can be relied upon for empirical treatment. There is concern that increasing use of vancomycin will select vancomycin-resistant strains of MRSA, so that, in the near future, there may no longer be any effective antibiotic therapy against hospital staphylococci.