Isolation of Acanthamoeba from a cerebral abscess.

A 55-year-old diabetic aboriginal woman presented with a two-week history of fever, altered mental state and convulsions. On the basis of computed tomographic scanning a diagnosis of cerebral abscess was made. The pus that was drained produced no bacterial growth but, on microscopy, amoebic cysts were observed. Special cultures produced a growth of Acanthamoeba. The patient appeared to respond to drainage of the abscess and antiprotozoal therapy. Unfortunately, she developed necrotizing enteritis which led ultimately to her death. Antibiotic sensitivity and pathogenicity testing suggest that the Acanthamoeba were unusually virulent. The problems of diagnosis and management are discussed.

Clostridium difficile colitis.

We reviewed all rectal biopsies performed on patients with proven C. difficile infection between 1977 and 1982 (36 patients). All patients were symptomatic and all had received antibiotic treatment recently, the commonest antibiotic treatment being ampicillin or amoxycillin. There was poor correlation between the histological appearances and the severity of symptoms. A range of histological appearances was observed: normal (8%), congestion and edema (8%), nonspecific colitis (3%), infective colitis (28%) and pseudomembranous colitis (53%) (PMC). Most cases of PMC showed 'early' features, involving predominantly the surface epithelium, where attenuation and inflammation, intraepithelial microabscesses, and small eruptive lesions were seen. Recognition of these features, in the context of an acute infective-type colitis, may lead to early diagnosis of C. difficile colitis.

Outbreak of brucellosis at a South-Australian abattoir. 2. Epidemiological investigations.

The outbreak of human brucellosis among employees of a large South Australian abattoir described previously coincided with an increase in the number of cattle showing a positive serological reaction for Brucella abortus being slaughtered. Comparisons showed that two other abattoirs in the area were slaughtering larger numbers of such cattle, but no cases of human brucellosis were diagnosed there. This suggested an additional risk at the abattoir concerned. All infected men had been employed in a particular part of the works. There was a possibility of movement of aerosols, produced on opening the uteri of pregnant cattle, to other parts of the works, putting a larger number of workers at risk of infection. Modifications to the plant greatly reduced the spread of aerosols. No cases of human brucellosis were recorded at this abattoir during the summer of 1980-81.

Outbreak of brucellosis at a South-Australian abattoir. 1. Clinical and serological findings.

During the period October 1979 to May 1980, 22 cases of acute brucellosis occurred at a South Australian abattoir. We obtained blood samples for serological investigations and culture of Brucella abortus, and tested the sera using the standard agglutination test (SAT), dithiothreitol test (DTT), anti-human globulin test (AHG) and complement fixation test (CFT). Patients showed large variations in antibody levels in each of these tests, both on presentation and after treatment. Blood culture was successful in six of 15 patients in whom it was attempted. Using the experience gained during the outbreak, we defined a set of serological criteria for the diagnosis of acute brucellosis, particularly in those who are occupationally exposed.

The importance of cephradine in hip surgery.

Effective concentrations of antibiotic in the fluid bathing implanted hip prostheses are essential to prevent infection by micro-organisms. Twenty patients undergoing total hip replacement were given one gram of Cephradine intramuscularly one hour before operation and one other received a single bolus of Cephradine intravenously before operation and one other received a single bolus of Cephradine intravenously before operation. The concentrations of antibiotic were greater and persisted longer in the tissue fluid than in the blood. The antibiotic was sufficient to inhibit most micro-organisms causing contamination. We recommend that Cephradine is given intramuscularly one hour before operation and at six-hourly intervals after operation until the drainage tubes and intravenous lines have been removed.

The rational use of antibiotics in general practice.

Many antibiotics produce serious adverse effects which, though uncommon, may be lethal or carry a high morbidity. This article provides a rational basis for the choice of antibiotics in common infections involving various anatomical sites. Short notes on the more useful antibacterial agents, dosage, major side effects and contraindications are included.