Background Chryseobacterium species are Gramnegative bacteria with an unusual antibiotic profile. Chryseobacterium meningosepticum is the species most commonly encountered as a human pathogen.

427 ~~The halophilic properties of 18 strains of Vibrio parahaemolyticus, including the type strain, were studied. The ability of the strains to grow in 0.1% trypticase containing isomolar concentrations of 10 different salts was tested. The results indicate that V. parahaemolyticus is capable of growing equally well in media containing salts other than NaCl and that it has no specific requirements for Na+ or C1-. I N T R O D U C T I O NVibrio parahaemolyticus is widely reported to be halophilic, requiring NaCl for its growth. All media used for its isolation and identification are supplemented with NaC1, but there have been reports of its isolation from fresh water sources (Cholera Research Centre, Calcutta, 1975). These reports prompted us to investigate the halophilic requirements of this organism. M E T H O D SStrains and their characterization. Eighteen strains of V. parahaemolyticus, including the type strain and another reference strain, were used in this study. Strains 1 (NCTC 10885) and 2 (NCTC 10903 -the type strain) were obtained from the National Collection of Type Cultures, Public Health Laboratory Service, Colindale, London. Strains 3 to 18 were isolated in this laboratory: strains 3 to 7 were from the faeces of cases of gastroenteritis and strains 8 to 18 from sea fish. These strains were identified as V. parahaemolyticus on the basis of the results obtained with the following tests: large colonies with dark green centres on thiosulphate/citrate/bile salt/sucrose (TCBS) agar: oxidase positive; good overnight growth at 37 OC in 1% (w/v) trypticase peptone water, when supplemented with 6 or 8% (w/v) NaCl but not with 10% NaCl or with no supplementary NaCl: good overnight growth at 42-43 "C in the same medium with 2% NaCl; fermentative reaction (acid, no gas) in the Hugh and Leifson oxidation/fermentation test; alkaline slant, yellow butt, no H,S in triple sugar iron agar: acetoin (Voges-Proskauer) negative; indole positive: lysine decarboxylase positive; and arginine dihydrolase negative. (Except where indicated, the above tests were made in media supplemented with 3 % NaCl.)Growth in the presence of salts and sugars. Tests were made of the ability of the strains to grow in 0.1 % (w/v) trypticase containing isomolar concentrations (0.1 M and 0.2 M) of the following inorganic and organic salts: Na,SO,; NaNO,, KCl, KI, K,SO,, MgSO,, MgCl,, sodium citrate and sodium acetate. Ability to grow in isomolar concentrations of glucose and sucrose was also examined. As controls, 0.1% trypticase containing 0.1 M-or 0.2 M-NaCl or no NaCl were used. The pH of the salt solutions without afiustment was 6.9-7.2. lsomolar concentrations were used so that the osmotic pressure of the different salt and sugar solutions would be similar, thus permitting comparison of their specific growth-promoting properties.Precautions were taken to minimize mineral contamination: Analar-quality salts and sugars were used, solutions were prepared with distilled water, and glassware was thoroughly rinsed with distilled water before use...

Thin‐layer chromatography (TLC) was employed as an alternative to gas‐liquid chromatography (GLC) for the analysis of typical fermentation end‐products of anaerobic Gram positive non‐sporing bacteria. The inexpensive TLC method succeeded in differentiating Actinomyces, Bifidobacterium, Lactobacillus and Propionibacterium. Ether extraction of supernatant was found to be unnecessary; volatile and non‐volatile acids were separated simultaneously, with consequent saving of time.

Background Peritoneal dialysis (PD) is an established form of therapy in the management of end stage renal disease. Peritonitis is the main complication of PD. Objectives To study the incidence and microbial aetiol ogy of peritonitis in patients undergoing chronic PD at the dialysis unit of Sri Jayewardenapura General Hospital (SJGH); to assess the diagnostic value of the Gram's stain; and to study the relationship of the total white cell count of effluent to peritonitis. Design A prospective, study over three months. Setting Dialysis unit of SJGH. Patient population The study involved 18 patients un dergoing manual intermittent peritoneal dialysis (IPD), 4 patients undergoing chronic ambulatory peritoneal dialy sis (CAPD), and 1 patient undergoing nocturnal intermit tent peritoneal dialysis (NIPD). Measurements Clinical presentation of patients with peri tonitis; total and differential white blood cell counts of effluent samples; Gram stain and culture of the centrifuged deposit to determine microbial aetiology; incidence of peri tonitis in different categories of dialysis. Results 32 samples were examined from patients on IPD, and 17 from patients on CAPD. In IPD most episodes were due to Gram negative organisms whereas in CAPD most episodes were due to Gram positive organisms. Sensitiv ity of Gram's stain in relation to culture was 32.4%. 98% of effluent samples had white blood cell counts of >100/ml and none showed neutrophil Counts of <49%. Conclusions The incidence of IPD associated peritonitis was 11.1 episodes per patient year, and the incidence of CAPD associated peritonitis was 14 episodes per patient year. Flavobacterium spp. were the predominant organ isms in IPD associated peritonitis, whereas CAPD associ ated peritonitis was commonly caused by coagulase nega tive staphylococci. Gram's stain was not useful in the ini tial identification of the causative agent, but the white cell and neutrophil counts were found to be sensitive indica tors of peritonitis.

Nine strains of Campylobacter fetus subsp. jejuni were isolated from the stools of diarrhoeic children in Colombo (Sri Lanka). The morphology of most of the strains was typical but three strains produced a spreading film of growth. No discrete domed colonies were seen. All were able to grow in a candle jar, and in a medium containing 1% glycine. All produced hydrogen sulphide. All were susceptible to ampicillin, carbenicillin, tetracycline, chloramphenicol, neomycin, erythromycin, gentamicin and furoxone .