Endocarditis due to Neisseria mucosa: two case reports and review.

Two cases of endocarditis caused by Neisseria mucosa are reported, and the literature on N. mucosa endocarditis is reviewed. N. mucosa is a rare but serious cause of endocarditis that is associated with a high rate of embolic complications and high mortality and is not always highly sensitive to benzylpenicillin. Most patients with N. mucosa endocarditis have been treated with combined therapy with penicillin and an aminoglycoside, although the optimal regimen has not been defined.

Investigation of nosocomial prosthetic valve endocarditis due to antibiotic-resistant Staphylococcus epidermidis.

A reservoir of antibiotic-resistant Staphylococcus epidermidis strains in our cardiac surgery unit appeared to be the source of organisms responsible for three cases of early prosthetic valve endocarditis. Staphylococcus epidermidis isolates recovered from the skin of 13 patients before and after surgery were compared. All were typed by plasmid profile, antimicrobial susceptibility and slime production. The three strains from early prosthetic valve endocarditis resembled the antibiotic-resistant nosocomial strains recovered from the skin of eight patients following surgery and the environment of the operating theatres. These strains expressed resistance to oxacillin, gentamicin, kanamycin and tobramycin and most produced slime, whereas those isolated from the skin of patients at the time of admission were predominantly susceptible to antibiotics and few produced slime.

Adaptation of methicillin-resistant Staphylococcus aureus during antibiotic therapy.

Colonization of a patient by methicillin-resistant Staphylococcus aureus (MRSA) of a single phage-type for over four years is described. During this period we observed the appearance and disappearance of resistance to erythromycin, clindamycin, gentamicin, kanamycin, tobramycin, neomycin and mupirocin. We also saw stepwise increases in methicillin resistance and reversible changes in physical appearance and the colonizer pathogen role. Correlation of clinical observations, details of antibiotic therapy and laboratory studies demonstrated that adaptation of MRSA during antibiotic therapy favoured MRSA establishment and predominance.

Melioidosis: a new disease to New Zealand.

The first case of melioidosis diagnosed in New Zealand is described. The patient presented with an abscess overlying the liver, which resolved on oral cotrimoxazole therapy, without the need for surgical drainage.

Cephalosporin susceptibility of methicillin-resistant, coagulase-negative staphylococci.

Coagulase-negative staphylococci were tested for susceptibility to methicillin, cephradine, ceftriaxone, cephalothin, and cefamandole by standard broth microdilution. Most of the 26 methicillin-resistant isolates were susceptible to cephalothin and cefamandole, but very few were susceptible to ceftriaxone, and none was susceptible to cephradine. The proportion of bacterial cells that grew in the presence of 128 micrograms of methicillin per ml was calculated for each methicillin-resistant isolate. Those with every cell or 1 in 10 cells resistant to 128 micrograms of methicillin per ml included the isolates that were most resistant to the cephalosporins and highly resistant to methicillin. Those with 1 cell resistant in 10(5) or 10(6) cells were the isolates most susceptible to the cephalosporins, and their methicillin MICs were lower. When cells resistant to 128 micrograms of methicillin per ml were used as inocula for broth microdilution tests, resistance to cephradine remained the same, but resistance to ceftriaxone, cephalothin, and cefamandole increased significantly. Cefamandole was the only cephalosporin which retained antibacterial activity against some methicillin-resistant isolates (12 of 26). Cephradine, ceftriaxone, cephalothin, and cefamandole resistance appeared to be expressed by the same cells that expressed methicillin resistance. In this way, cross resistance was demonstrated between methicillin and the cephalosporins.

Blood culture isolates at Green Lane Hospital, 1972-1982.

Bacteraemic patients identified annually at Green Lane Hospital by positive blood culture increased by 215% between 1972 and 1982. In the same period the patient population increased by 22%. There was a disproportionate increase in gram-positive organisms. Antibiotic sensitivity patterns are discussed.

Culture negative infective endocarditis.

Twenty cases of culture negative infective endocarditis admitted to the Cardiology Department of Green Lane Hospital from 1959 to 1980 out of a total of 265 cases (7.5%), were analysed retrospectively. Cases were included only when adequate proof of endocarditis was available at surgery or postmortem. Indiscriminate use of antibiotics before taking blood cultures was the most common association with failure to obtain positive cultures, seen in 16 of the 20 patients described. Failure to obtain positive cultures in four cases was attributed to inadequate bacteriologic techniques before 1967. Where no antibiotics were given prior to collecting blood cultures and bacteriologic techniques were adequate, proven culture negative endocarditis was virtually unknown. When antibiotics have been given, repeated blood cultures are recommended following withdrawal of antibiotic for at least four days.

In-vitro activity of cefoxitin against recent clinical bacterial isolates.

The susceptibility of 635 clinical isolates of bacteria to cefoxitin was determined. Isolates from the urinary tract showed 97% sensitivity, isolates from infected wounds showed 93% sensitivity and 82% of blood culture isolates were sensitive. Streptococcus faecalis isolates showed only 50% sensitivity and pseudomonas organisms were predominantly resistant. Bacteria isolated from unprepared heart valves submitted for use as homografts showed only 71% sensitivity due to the large proportion of Streptococcus and Pseudomonas species isolated.

Bacterial contamination of radial artery catheters.

A prospective survey of 113 radial artery catheters showed a total contamination rate using an enrichment media culturing technique of 39%. The yield from routine culturing alone was only 9%. In six cases pathogenic bacteria were isolated. In this study no correlation between contamination and aspects of catheter insertion and management was shown.

Endocarditis due to Citrobacter diversus developing resistance to cephalothin.

A 43-year-old man was admitted with acute bacterial endocarditis. Citrobacter diversus susceptible to cephalothin was isolated from blood cultures. Citrobacter diversus was later isolated from the aortic valve cusps at surgery, but this isolate was resistant to cephalothin. Laboratory testing showed that the Citrobacter diversus recovered from blood cultures was capable of producing mutants highly resistant to cephalothin.

Onychomycosis due to Aspergillus candidus: case report.

A patient is described who suffered from chronic fungal involvement of right great toe nail. Serial cultures of the removed nail demonstrated a non-dermatophyte, Aspergillus candidus, as the causative agent.

In vitro resistance of haemophilus influenzae to co-trimoxazole and trimethoprim.

Over a period of five months Haemophilus influenzae isolated from 123 patients were tested for resistance to co-trimoxazole and trimethoprim by the disc method of sensitivity testing and isolates from four patients were found to be resistant. However, the minimum inhibitory concentrations of trimethoprim lactate were estimated for the isolates from these four patients only one was found to be resistant. This H. influenzae strain was from one of the two patients in the survey who had a history of repeated courses of co-trimoxazole therapy. The discrepancy between the results of the disc sensitivity tests and the minimum inhibitory concentration estimations of the resistance of H. influenzae to co-trimoxazole and trimethoprim. The appearance of co-trimoxazole and trimethoprim resistance in H. influenzae isolated from a patient who has had prolonged treatment with co-trimoxazole is in agreement with the findings of other authors.

Torulopsis glabrata endocarditis complicating aortic homograft valve treated with 5-fluorocytosine: case report with discussion of antifungal chemotherapy.

A case of Torulopsis glabrata endocarditis occurring in a patient 14 months after aortic homograft valve replacement is reported. The infection was not controlled by amphotericin B which led to progressive renal impairment. Re-operation was delayed by the development of multiple infarctions due to coronary emboli. The infection was subsequently eradicated by oral treatment with the newer antifungal agent, 5-fluorocytosine, but death of the patient eventually occurred from an arrhythmia related to the persisting myocardial failure consequent upon episodes of transmural infarction. Current evidence favours the use of early re-operation in all cases of endocarditis in addition to aggressive chemotherapy with a combined regime of amphotericin B and 5-fluorocytosine. Clinical pharmacology of 5-fluorocytosine is briefly discussed.

The effect of bilirubin on the assay of gentamicin.

An experiment was set up to examine the effect of ;jaundiced' serum on the estimation of gentamicin levels in serum. Varying amounts of gentamicin were assayed in the presence of a range of bilirubin concentrations and compared with assayed levels in normal serum.