The serological relationship between Escherichia coli O157 and Yersinia enterocolitica O9 using sera from patients with brucellosis.

Sera from ten patients with positive brucella serology were used to investigate antibody cross-reactions between the O-antigens of Escherichia coli O157 and Yersinia enterocolitica O9. SDS-PAGE profiles of lipopolysaccharide (LPS), purified from strains of E. coli O157 and Y. enterocolitica O9, were reacted with sera by immunoblotting. All ten sera contained antibodies which bound to the LPS of E. coli O157, and five of these sera also contained antibodies which bound to the LPS of Y. enterocolitica O9. Absorption studies using these five cross-reacting sera indicated the existence of at least three epitopes exposed on the O-antigens of E. coli O157 and Y. enterocolitica O9. One antigen binding site appeared to be exposed on the LPS of both organisms, while one epitope was exposed on the LPS of E. coli O157 only, and another on the LPS of Y. enterocolitica O9 only.

Rabies presenting with myocarditis and encephalitis.

We report a case of rabies acquired in Zambia by a 45-year-old woman who presented with a history of an influenza-like illness, abnormal behaviour and signs of myocarditis. A provisional diagnosis of systemic viral infection was made. Within 12 h of admission the patient developed features of rabies that included hydrophobia. She was artificially paralysed and ventilated electively. Empirical antibiotic therapy was given also. Signs of myocarditis and fever disappeared within 48 h. Her clinical condition remained stable but she required heavy sedation. On the ninth day after admission the patient developed features of inappropriate secretion of antidiuretic hormone and gradually became water-logged. Intake of fluid was therefore restricted. Her level of consciousness deteriorated progressively to the point where sedation was no longer required. Brain death was diagnosed 14 days after admission.

Rat-bite fever in a gerbil breeder.

A case of rat-bite fever caused by Streptobacillus moniliformis in a gerbil-breeder is described. Such a case has not been previously recorded.

Neonatal listeriosis due to cross-infection in an obstetric theatre.

Two cases of neonatal listeriosis following Caesarean section are reported. Evidence is presented which suggests that cross-infection took place in the obstetric operating theatre. The first case shows the features of early-onset disease while the second illustrates the late-onset pattern. Listeria monocytogenes was isolated also from the mother of the first baby. The two neonatal disease patterns are discussed.

Diagnosis of Bacteroides fragilis infection with counter-immunoelectrophoresis.

In a study of 188 patients and 109 controls, the detection of antibody by counterimmunoelectrophoresis was used as a diagnostic aid in human infections with Bacteroides fragilis. It was found that positive results indicated current infection and negative results were not conclusive. The method used was simple, rapid, and easily performed in a routine laboratory, but further work is needed to enhance antigen potency.

Human infections with thymine-requiring bacteria.

Clinical details are presented of 16 patients from whom thymine-requiring (thy-) mutants of pathogenic organisms were isolated; all had been treated with co-trimoxazole. The urine of six patients infected with thy- mutants contained levels of a thymine-like compound sufficient to support their growth. This might be the result either of the breakdown of pus cells or of thymine production by living bacteria that persist in stones or scar tissue, a suggestion supported by the observation of mutant growth "in satellitism" in vitro. Since 1975 we have isolated mutants from patients who have had short courses of co-trimoxazole, in contrast to those we reported upon previously, all except one of whom had had long courses. We are now isolating thy- mutants more frequently than hitherto. Secondary mutations to a low thymine requirement may now be occurring more rapidly, thereby allowing more mutant organisms to survive. The clinical significance of infection with thy- mutants is not yet clear, but evidence is accumulating that they are pathogenic. Alternative chemotherapy is suggested for patients from whom such mutants have been isolated.

Thymine-requiring bacteria associated with co-trimoxazole therapy.

Since 1971 thymine-requiring (thy-) pathogens have been isolated from the urine of 8 patients with renal calculi, and from the sputum of 1 patient with chronic chest infection. The patients had been treated with co-trimoxazole for several months before the isolation of the mutant pathogens. There was persistent pyuria in the patients with renal calculi, and purulent sputum in the patient with chronic chest infection. The mutants were identified by their inability to grow on diagnostic sensitivity test agar (D.S.T., Oxoid) which is deficient in thymine. It was found that wild-type bacteria can produce growth factors for the metabolism of the mutants in vitro, and the urine of the patients contained by thymine-like compounds. These findings indicate that thy- mutants may develop in renal calculi during co-trimoxazole therapy. Therapy should be changed to a more suitable antimicrobial as soon as possible after diagnosis of mutant infection.