RAPID RECOGNITION OF GROUP-B STREPTOCOCCI

256

patients who were cared for by a nurse (later identified as a carrier) for only one eight-hour period. We found no environmental sites contaminated with the resistant organisms, and did not feel it necessary to fumigate or change routine cleaning procedures in any way. We would like to stress the propensity of these methicillin-resistant staphylococci to colonise personnel and patients alike and to cause serious disease and even death in the compromised hosts so often found in hospital. Division of Infectious Disease, JOSEPH J. KLIMEK Hartford Hospital, RICHARD QUINTHIANI Hartford, Connecticut 06115, U.S.A.

considered as disinfection with a reasonable possibility of sterilisation after a 2 h cycle. The miniclave represents an important advance over other methods of treating cystoscopes and some other endoscopes, and it could be improved by small modifications. Infection Research Laboratory, Summerfield Hospital, Birmingham B18 7QQ

Hospital

G. A. J. AYLIFFE C. E. A. DEVERILL

Engineering Department, West Midlands

N. CRIPPS

Leeds

G. L. GIBSON

Regional Health Authority Public Health Laboratory,

DISINFECTION OF CYSTOSCOPES BY LOW-TEMPERATURE STEAM

SIR,-Urinary-tract infection is still the most frequently acquired hospital infection, and, although usually associated with catheterisation, it can result from inadequately disinfected cystoscopes. Chemical solutions are commonly used for disinfection and have a number of disadvantages, particularly the possible failure of contact between the disinfectant and the surfaces of the cystoscope. Sterilisation by autoclaving at high temperature is the most reliable method but is rarely possible. A bench-top, transportable low-temperature steam (L.T.s.)/formaldehyde autoclave, the ’Miniclave 80’ (Thackray) has recently become available commercially. It has a chamber size of about 1 c. ft. (27 1) and will hold four cystoscopes packed in boxes as described by Mitchell and Alder.1 Since the miniclave 80 is relatively inexpensive and is obviously attractive to urological surgeons and theatre staff, some comments on

its present

uses

and limitations

by a cystoscope. L.T.s./formaldehyde autoclaves still require close supervision by engineers and microbiologists, and the miniclave 80 is no exception. Care should be taken to avoid overheating of non-metallic items. The L.T.s./formaldehyde process should be Mitchell, J. P., Alder, V. G. Br. J. Urol. 1975, 47, 571. Line, S. J., Pickerill, J. K. J. clin. Path. 1973, 26, 716. Gibson, G. L. ibid. (in the press). Weymes, C., White, J. D., Harris, C. in Note 4, Greater Glasgow Health Board Sterilisation Centre, 1975. 5. Cripps, N., Deverill, C. E. A., Ayliffe, G. A. J. Hosp. Eng. 1976, 30, no. 19

p. 9.

PIGMENT PRODUCTION BY GROUP-B STREPTOCOCCI ON NEW MEDIUM AND COLUMBIA AGAR AFTER

16-20 h ANAEROBIC

INCUBATION

are neces-

sary. Tests made in Birmingham showed that small number of spores survived in 5/32 (15%) of Bacillus stearothermophilus spore strips (Oxoid) after a 2 h exposure at 72°C with 10 ml formaldehyde. Spore strips were placed in various sites including a cystoscope and the Alder test piece. All spore strips placed in a metal helixl showed growth. At the end of a 2 h cycle, temperatures of 78-91°C were recorded on thermocouples attached to airways and cardiac catheters but lower temperatures were obtained with metallic objects. The mean temperature recorded on a cystoscope after a 20 min disinfection cycle was 74°C. Tests for disinfection using Streptococcus fcecalis as the test organism were satisfactory after the 20 min cycle. Although a reduction of spores by at least 1O was obtained, apart from in the helix, after a 2 h L.T.s./formaldehyde cycle in three cycles, sterilisation could not be guaranteed if the usual criteria for heat sterilisation were applied. Extensive tests in Leeds using a variety of test pieces3 showed that disinfection was easily achieved using a 20 min cycle. B. stearothermophilus spores on Oxoid spore strips were killed in the Alder test piece in 1 Zh cycles with formaldehyde but tests in a standard Line and Pickerill helix were not successful even after prolonged exposures of up to 3 ih and high concentrations of formaldehyde. Sterilisation was a little more easily achieved in a modified helix4 with a 3-5 5 ml chamber but was still not satisfactory. The relevance of the metal helix as a test piece is uncertain. It is designed to simulate conditions in an arterial catheter and this is certainly a much more difficult challenge than is offered

1. 2. 3. 4.

RAPID RECOGNITION OF GROUP-B STREPTOCOCCI SIR,-In the past decade perinatal morbidity and mortality and septicaemic conditions in previously healthy adults caused by group-B streptococci (Streptococcus agalactice) have been increasingly reported.1-6 Screening of *pregnant women and the newborn has been recommended,4 but a simple, rapid, and consistent screening test for group-B streptococci remains to be developed. While examining the cultural characteristics of the genitourinary flora on starch/serum agar (a differential medium for the isolation of Corynebacterium vagina Ie ), I noted that most of the group-B streptococci were producing deep orange-red

H=haemolytic

*p<0-001

colonies on this medium, and the pigment seemed to be more intense and easily detectable than on Columbia agar (which contains 0-1% of starch).’O The study was extended, and a pigment-enhancing medium has been developed which has shown consistent improvement in pigment production. The new medium is modified starch/serum agar with the formula (g/1): proteose peptone no. 3 (Difco) 23.0, soluble starch (B.D.H.) 5.0, sodium dihydrogen phosphate dihydrate 1-482, disodium hydrogen phosphate 5.749, agar no.1 (Oxoid) 10.0, distilled water to 1 litre. The medium (whichis buffered with 0-1mol/1 phosphate buffer pH 7-4) is warmed in free steam for 5 min, then mixed and autoclaved for 15 min, and cooled to 55°C. 50 ml of sterile inactivated horse serum is added and plates (about 40) are poured. Alternatively, 50 plates may be prepared and then layered over with the same medium (5-6 ml/plate) containing 5% oxalated horse blood (instead of serum). The special peptone (Oxoid) used in starch serum agar’O is slightly inferior to proteose peptone, while poor results are obtained with Oxoid nutrient agar. Eickoff, T. C., Klein, J. O., Daly, A. K., Ingall, D., Finland, M. New Engl. J. Med. 1964, 271, 1221. 2. Butter, M. N. W., deMoor, C. E. Antonie van Leeuwenhoek, 1967, 33, 439 3. Baker, C. J., Barrett, F. F., Gordon, R. C., Yow, M. D. J. Pediat. 1973, 82, 1.

724. 4. Franciosi, R. A., Knostman, J. D., Zimmerman, R. A. ibid. 1973, 5. Mhalu, F. S. J. clin. Path. 1976, 29, 309. 6. Parker, M. T., Ball, L. C. J. med. Microbiol. 1976, 9, 275. 7. Baker, C. J., Barrett, F. F. J. Pediat. 1973, 83, 919. 8. Finch, R. G., French, G. L., Phillips, I. Br. med. J. 1976, i, 1245. 9. Islam, A. K. M. S. J. clin. Path. (in the press). 10. Fallon, R. J. ibid. 1974, 27, 902.

82, 707.

257 The pigment-producing ability of 68 strains (including 19 non-tMemotytic/anima!) of group-B streptococci and a type strain (NCTC 8181) on the new pigment-enhancing medium has been compared with that on Columbia agar (Oxoid). The cultures were incubated at 37°C anaerobically using a ’Gas Pak’ (B.B.L.), the presence or absence of orange-red pigmented colonies and haemolysis (on overlayered plates) were recorded (as ++, +, or 0) after 16-20, 48, and 72 h incubation. The

pigment-enhancing medium (used as either single or overlayered plates) is strikingly superior in pigment production to Columbia agar (see table). Moreover, haemolysis can be seen better on the overlayered plates than on the commonly used blood agar; other genital bacteria causing perinatal infections (e.g., anaerobic streptococci and Bacteroides and Clostridium spp.) appear to grow luxuriantly on this new medium. None of the other serogroups of streptococci (A, C, D, G and F) produce any pigment. Satisfactory isolation results of group new

B have been found in mixed cultures. Department of Pathology, St Peter’s Hospitals and Institute of Urology, London WC2H 9AE

A. K. M. S. ISLAM

PREVENTING NUTRITIONAL RICKETS

SIR,-Suggestions that nutritional rickets in Britain could largely be prevented by fortifying chupatty flour with vitamin D’rest on the assumption that those at risk eat chupatties. We have examined the records of patients presenting at this hospital with nutritional rickets to determine the ages and ethnic backgrounds of the patients concerned. Cases of nutritional rickets admitted to the wards or seen in the orthopaedic outpatients clinic were included provided that they responded to small doses of vitamin D and that they were free of intestinal diseases and not taking anticonvulsants. There were 22 cases between 1970 and 1976. 20 were born in London and 1 each in India and Pakistan. All the parents were born overseas, the distribution being as follows: India 7, West Indies 5, Pakistan 4, Cyprus 3 (all Turkish), and Nigeria 3. All but 7 children were between 16 and 31months old (11 girls, 4 boys). 2 girls and 1 boy were younger and 4 boys were older (4-8 years). Most of the children were taking a normal mixed diet; 3 children over 1 year were largely breast fed; nearly all the remainder drank substantial quantities of dairy milk. It seems that in this area of East London, which has a large mixed immigrant population, rickets affects mainly toddlers and these are found among most immigrant groups. Only half the series were Asians and while most of these were from the North and West of the Indian subcontinent where chupatties are eaten2 some of them had not yet been weaned onto a cereal-containing diet. We suggest that the resurgence of infantile rickets in this area is due to a combination of culturally conditioned aversion to sunlight, poor housing, and inadequate nutrition. It seems unlikely that fortifying the food of one particular ethnic group can provide an answer to the problem. Efforts to urge immigrant parents to provide their children with vitamin drops until they are at least 3 years old should be increased. Alternatively thought could be given to the possibility of fortifying dairy milk with vitamin D. This is done in the United States where nutritional rickets is almost unknown. Queen Elizabeth Hospital for Children, J. M. GERTNER Hackney Road, London E2 8PS BRENDA LAWRIE

PREGNANCY-ASSOCIATED &agr;2-GLYCOPROTEIN SIR,-Pregnancy-associated ot.-glycoprotein (P.A.G.) is sometimes raised in the sera of patients with metastatic cancer’ and has been proposed as a useful marker for monitoring the progression of cancer of the breast.’The Lancet’ expressed cautious optimism for the use of P.A.G. as a monitor of cancer progression although recent reports have5 not shown increased P.A.G. levels in certain cancer patients.4 We wished to determine the role of P.A.G. in the diagnosis and monitoring of patients with neoplasia. Patients with breast, lung, colonic, and gynaecological (endometrium, cervix, ovary, vulva) tumours were studied and classified into local or disseminated disease. Control groups included healthy women and patients with inflammatory bowel disease. P.A.G. was measured by rocket immunoelectrophoresis (coefficient of variation

5%). Our results are illustrated in the figure. Patients with lung, breast, and colonic cancers showed no significant differences between local and metastatic disease using the KolmogorovSmirnov rank test (p>0-05), and the latter group did not differ in P.A.G. concentrations from those with inflammatory bowel disease. Some patients with disseminated breast cancers had higher P.A.G. concentrations than did controls. However, most were within the range for local breast cancer, and many of the patients were receiving hormone treatment. Eleven patients with breast cancer have been followed up for eight months and definite clinical progression or regression of disease carefully recorded. Regression of disease was noted on three occasions. In each case the serum-P.A.G. decreased. Clinical progression of disease was observed on thirteen occasions. In four cases progression was accompanied by rising P.A.G. concentrations. However, in the remaining nine P.A.G. remained unchanged or decreased. Changes in P.A.G. concentration were generally taken to be significant if in excess of 35% of the initial concentration.

1. Stimson, W. H. J. clin. Path. 1975, 28, 868. 2. Stimson, W. H. Lancet, 1975, i, 777. 3. ibid. 1975, ii, 1192. 4. Damber, M.-G., Von Schoultz, B., Sugbrand, T. ibid. 1975, i, 1182. 5. Von Schoultz, B., Damber, M.-G., Sugbrand, T. Proc. 24th Colloq. Protides biol. Fluids, 1976, p. 189.

P.A.G. concentrations.

1 Pietrek, J., Preece, M. A., Windo, J., O’Riordan, J. L. H., Dunmgan, M. G., McIntosh, W. B., Ford, J. A. Lancet, 1976, i, 1145. 2 Community Relations Commission (Social Services Section). A Guide to Asian Diets. London, 1976.

(A) healthy women; (B) cancer of the breast; (C) gynaecological can(D) cancer of the lung; (E) cancer of the colon; (F) inflammatory

cers ;

bowel disease. 8=disseminated

cancer.

O=local disease.