1355

could elicit a hypersensitivity reaction at these sites.The fact that we were unable to relate skin hyper-sensitivity to the lesion formation after intravenous

injection might be because of differences in responsein the tissues compared to the skin. If the reactionwas wholly or predominantly one of delayed hyper-sensitivity rather than an immediate type, this wouldexplain the ineffectiveness of antihistamine treatment.However, anaphylactoid reactions have been observedin man 5 after successive intralesional injections, so

pretreatment with antihistamine in these circumstancesmay be a wise precaution.6The results we have obtained in guineapigs reinforce

our misgivings about use of B.C.G. intravenously. Wefeel that the vaccine should only be given by this routewith extreme caution and in low doses, along the linestried by Whittaker et aUThe results may also be relevant to the side-effects

reported after B.C.G. administration by some otherroutes.8 Fever, malaise, hepatic dysfunction, and

jaundice have been most frequently associated withintralesional treatment,9 where rapid transfer into thebloodstream has been demonstraxed 1° There are

reports of disseminated B.c.G. infection having occurredbut where control was achieved by isoniazid or anti-biotics.9,ll,12 Others have recognised the possiblecomplication of hypersensitivity,6 and the seriousnessof this has recently been underlined by reports of twodeaths attributed to hypersensitivity after intralesionalB.C.G.13,14 Morton’s group have controlled the compli-cations due to hypersensitivity by pretreating with.antihistamines and aspirin and adjusting the dose ofB.c.G. according to the patient’s degree of hypersensi-tivity. Morton’s experience of intralesional injectionwas with B.c.G. vaccine of the same manufacture asthat used here, for which he stated a preferencebecause of the high proportion of viable organismscompared with other preparations.13,14 This is inline with the conclusions from our guineapig experi-ments. The use of killed B.c.G. vaccine is thereforenot advised.

We thank Mrs Patricia J. Boulton for technical assistanceand Dr A. T. A. Doble for his help in histological assessment.

Requests for reprints should be addressed to P. W. M.

REFERENCES

1. Zbar, B., Bernstein, I. D., Rapp, H. J. J. natn. Cancer Inst. 1971,46, 831.

2. Baldwin, R. W., Pimm, M. V. Eur. J. clin. biol. Res. 1971, 16, 875.3. Baldwin, R. W., Pimm, M. V. Br. J. Cancer, 1973, 27, 48.4. Baldwin, R. W., Pimm, M. V. Int. J. Cancer, 1973, 12, 420.5. Morton, D. L., Holmes, E. C., Eilber, F. R., Wood, W. C. Ann.

intern. Med. 1971, 74, 587.6. Hunt, J. S., Silverstein, M. J., Sparks, F. C., Haskell, C. M.,

Pilch, Y. H., Morton, D. L. Lancet, 1973, ii, 820.7. Whittaker, J. A., Lilleyman, J. S., Jacobs, A., Balfour, I. ibid. 1973,

ii, 1454.8. Bast, R. C., Zbar, B., Borsos, T., Rapp, H. J. New Engl. J. Med.

1974, 290, 1458.9. Sparks, F. C., Silverstein, M. J., Hunt, J. S., Haskell, C. M.,

Pilch, Y. H., Morton, D. L. ibid. 1973, 289, 827.10. Pinsky, C., Hirshant, Y., Oettgen, H. Proc. Am. Ass. Cancer Res.

1972, 13, 21.11. Mansell, P. W. A., Krementz, E. T. J. Am. med. Ass. 1973, 226, 1570.12. Grant, R. M., Mackie, R., Cochran, A. J., Murray, E. L., Hoyle, D.,

Ross, C. Lancet, 1974, ii, 1096.13. McKhann, C., Gunnarsson, A. in Neoplasm Immunity: BCG

Vaccination (edited by R. G. Crispen); p. 31. Evanston, Illinois,1974.

14. Spider, L. E., Wybran, J., Lieberman, R., Levinson, D., Epstein, W.,Hendrickson, C. ibid. p. 45.

INFECTION CAUSED BY PROTEUSMIRABILIS STRAINS WITH TRANSFERABLE

GENTAMICIN-RESISTANCE FACTORS

M. S. SHAFI

Department of Microbiology, Central Middlesex Hospital,London NW10 7NS

NAOMI DATTA

Department of Bacteriology, Royal Postgraduate MedicalSchool, London W12 0HS

During a period of 10 weeks, fourSummary patients in one hospital became infected

with gentamicin-resistant Proteus mirabilis. In twoof them, septicæmia associated with indwellingcatheters developed, one had urinary tract and woundinfections, and in the fourth patient the organism wasisolated from a superficial wound. The P. mirabilisstrains showed multiple drug resistance. Strains fromthe first three patients were apparently identical andwere sensitive to tobramycin. Their gentamicinresistance was not transferable to Escherichia coli K12,but could be transferred to another strain of P.mirabilis (PM13-3). The fourth strain was resistantto tobramycin; its gentamicin/tobramycin resistancewas transferable to E. coli K12.

Introduction

MANY infections in hospital patients are caused bygram-negative bacilli. In serious and possibly life-

threatening infections, gentamicin, sometimes in com-bination with other drugs, is often prescribed to

provide effective cover against a wide range ofbacterial Gentamicin is used either when thecausative organism is not known or because it hasbeen shown to be the only effective drug to which theorganism is sensitive. Although there have been

reports of gentamicin resistance in Pseudomonasa-mginosa, such resistance has so far been uncommonamong other aerobic gram-negative bacilli.2,3 Strainsof Proteus mirabilis are generally more sensitive to

antimicrobial drugs than strains of other Proteus spp.We describe four patients with infection caused by

gentamicin-resistant P. mirabilis.

Patients

Patient 1.-A 62-year-old woman was admitted withhead injury and multiple fractures resulting from a roadaccident. 12 days after admission she was transferred tothe intensive-care unit because of renal failure. Sep-ticxmia developed which was almost certainly derived fromurinary-tract infection associated with an indwellingcatheter. P. mirabilis, resistant to gentamicin as well asto other antimicrobial drugs, was isolated from a catheterspecimen of urine and from the patient’s bloodstream(strain A). Treatment with gentamicin was started beforethe results of cultures were known. Subsequent culturesof blood did not yield bacterial growth. The patientrecovered.

Patient 2.-A 58-year-old man was admitted for

investigation of polyneuritis. During his stay in hospital,flaccid paralysis involving the muscles of respirationdeveloped and he was transferred to the intensive-careunit. Septicaemia developed which, as in patient 1, wasassociated with an indwelling catheter. P. mirabilis re-

1356

PROPERTIES OF GENTAMICIN-RESISTANT P. MIRABILIS STRAINS

Minimum inhibitory concentration (M.i.c.) was the lowest concentrationof drug in diagnostic sensitivity test agar (Oxoid) to prevent visiblegrowth from a surface inoculum of a 4-hour broth culture.

Gm = gentamicin; Tb = tobramycin; Cb = carbenicillin/ampicillin;Sm = streptomycin; Tc = tetracycline; Km = kanamycin; Cm =chloramphenicol; Su=sulphonamide; Tp=trimethoprim; Ct=colistin; Cp = cephaloridine.

’PM13-3 is a mutant of PM13" resistant to nalidixic acid andrifampicin.

sistant to many antimicrobial drugs, including gentamicin,was isolated from his bloodstream (strain B) and from hisurine. The patient was treated with gentamicin and benzylpenicillin. Subsequent blood-cultures proved negative, butthe organism persisted in his urine. After antimicrobialtreatment had been discontinued, septicaemia againdeveloped and blood-cultures yielded an identical resistantstrain of P. mirabilis. Because of the previous response totreatment with gentamicin and the apparent lack of anyother effective antimicrobial drug, the patient was thentreated with a combination of carbenicillin and gentamicinbut he died.

Patient 3.-A 69-year-old man was admitted with anabdominal aortic aneurysm, which was excised and re-

placed by an aorto-femoral graft. However, furtheraneurysms developed and he was operated upon again.After this he was transferred temporarily to the intensive-care unit before returning to a surgical ward. This patienthad an indwelling catheter, and a urinary-tract infectiondeveloped which was treated by noxythiolin bladder wash-

outs. P. mirabilis resistant to gentamicin, was isolatedfrom his urine (strain C) and subsequently from his wound.The only antimicrobial therapy given was a short post-operative course of ampicillin and cloxacillin. The patientdied.

Patient 4.-A 62-year-old woman with severe

rheumatoid arthritis was admitted to hospital for total hipreplacement. 3 weeks after operation, when the dressingwas removed, the wound appeared healthy, but about 10cm. below the suture line there was excoriation of the skin(7 cm. x 10 cm.) where adhesive plaster had been applied.A strain of P. mirabilis (strain D) with multiple resistancewas isolated from the site. Simple dry dressings wereapplied and the superficial wound healed.

Bacteriological InvestigationsThe organisms isolated from all four patients were

identified as typical P. mirabilis by the criteria ofCowan and Steely Disc diffusion tests showed allfour strains to be resistant to ampicillin, carbenicillin,cephaloridine, streptomycin, tetracycline, kanamycin,sulphonamide, and trimethoprim as well as to genta-micin. Strains A, B, and C were also resistant to

chloramphenicol and colistin; strain D was sensitiveto these two drugs.The four strains were typed in the Cross Infection

Reference Laboratory, Central Public Health Labora-tory, Colindale, and were found to be of proticine type2. When tested by Diene’s method, however, strainD was distinguishable from strains A, B, and C. Thelatter three strains were indistinguishable.Of the four strains, only D transferred gentamicin

resistance to Escherichia coli K12 when tested as pre-viously described.5 Gentamicin resistance was nottransferable from strains A, B, and C to E. coli K12,but it was transferable to another strain of P. mirabilisPM13-3 (see accompanying table). In each case

multiple drug resistance was transferred.

Discussion

Strains of P. mirabilis (A, B, and C) from the firstthree patients were indistinguishable. The patientshad been in the intensive-care unit at some time duringthe period of their stay in the hospital but not at thesame time. Cross-infection was probable, but an

identifiable source in the environment was not found.Strain D, from the fourth patient, was different andwas isolated from a superficial lesion in a patient whohad not been in the intensive-care unit.

Because gentamicin-resistant bacteria are still rarein clinical practice, this drug is commonly used to

treat life-threatening infections before the causative

organism can be isolated and tested for drug sen-

sitivity. Such routine use of gentamicin in hospitals,however, is likely to increase the frequency of resistantbacteria. Gentamicin resistance in bacteria ariseseither by mutation or by the acquisition of resistance(R) factors. Gentamicin R factors have been identifiedin several bacterial genera in various geographicalareas 6-ro but have not previously been reported in theU.K. The presence of at least two types of gentamicinR factor in recent isolates of P. mirabilis in one hospitalis disquieting. Each of the two types of R factor washarboured by a distinguishable strain of P. mirabilis.The R factor from these strains differed in their host

ranges and also in their resistance patterns.Tobramycin is an aminoglycoside antibiotic closely

related to gentamicin, having similar degree of toxicitybut with greater activity against Ps. ceruginosa. Itsactivity against enterobacteria and staphylococci, how-ever, is similar to that of gentamicin 11 Gentamicin-resistant strains of Ps. ceruginosa and other aerobicgram-negative bacilli are often resistant also to

tobramycin 12; laboratory selection using either drugresults in resistance to both." Crowe and Sanders 13reported that most resistant clinical isolates were

resistant to both drugs, but some gentamicin-resistantstrains were tobramycin sensitive, and a few genta-micin-sensitive strains were resistant to tobramycin.R factors have been identified which determine eachof these three patterns of resistance," depending uponwhich of the aminoglycoside-inactivating enzymes is

produced.15In the two patients with septicaemia, treatment with

gentamicin was started before the causative organismwas isolated and found to be resistant to this drug

in vitro. The first patient recovered, but the second

1357

patient, although showing initial progress, eventuallydied. Only later were the strains tested againsttobramycin and found to be susceptible to this drug.The presence of two types of R factor, with differentpatterns of resistance to gentamicin and tobramycin,indicates that results of in-vitro susceptibility tests

against one drug cannot be applied to the other.

Clearly, strains of aerobic gram-negative bacilli causingserious illness should be tested against each of thesedrugs separately before it is decided which is the moreappropriate in a given clinical situation.

Requests for reprints should be addressed to M. S. S.

REFERENCES

1. Lowbury, E. J. L., Ayliffe, G. A. J. Drug Resistance in Anti-microbial Therapy. No. 938, American Lecture Series, Spring-field, Illinois, 1974.

2. Noone, P., Pattison, J. R., Davies, D. G. Postgrad. med. J. 1974,50, suppl. p. 9.

3. Anderson, F. M., Datta, N., Shaw, E. J. Br. med. J. 1972, iii,82.

4. Cowan, S. T., Steel, K. J. Manual for the Identification of MedicalBacteria. London, 1974.

5. Datta, N. in Recent Advances in Clinical Pathology (edited byS. C. Dyke); p. 43. London, 1968.

6. Witchitz, J. L., Chabbert, Y. A. Annls Inst. Pasteur, Paris, 1972,132, 367.

7. Lemosquet-Villemon, M., Morel, C., Freymuth, F. Path. Biol.1972, 21, 227.

8. Martin, C. M., Ikari, N. S., Zimmerman, J., Waitz, A. J. J. infect.Dis. 1971, 124, suppl. p. 24.

9. Bryan, L. E., Semaka, S. D., van den Elzen, H. M., Kinnear, J. E.,Whitehouse, R. L. S. Antimicrob. Ag. Chemother. 1973, 3, 625.

10. Jacoby, G. A. ibid. 1974, 6, 239.11. Waterworth, P. M. J. clin. Path. 1972, 25, 979.12. Brusch, J. L., Barza, M., Bergeron, M. G., Weinstein, L. Antimicrob.

Ag. Chemother. 1972, 1, 280.13. Crowe, C. C., Sanders, E. ibid. 1972, 2, 415.14. Jacoby, G. A. ibid. 1974, 6, 807.15. Benveniste, R., Davies, J. A. Rev. Biochem. 1973, 42, 471.16. Coetzee, J. N. Ann. Rev. Microbiol. 1972, 26, 23.

POSTOPERATIVE THROMBOSIS IN THAI

WOMEN

T. CHUMNIJARAKIJ V. POSHYACHINDA

World Health Organisation Research Team on ClinicalEvaluation of Fertility Regulating Agents, Chulalongkorn

Hospital and Medical School, Bangkok, Thailand

Summary The 125I-labelled fibrinogen infusiontest and phlebography were used to

detect evidence of the postoperative development ofdeep-vein thrombosis (D.V.T.) in the legs of 117 Thaiwomen who had abdominal hysterectomy for benignconditions and of 52 who had major pelvic surgeryfor malignant disease of the ovary, uterus, and cervix.D.V.T. was demonstrated in 1·7% and 3·8%, respec-tively. Comparison of these results with an almostidentical study in Oxford showed that D.V.T. was

significantly more common in women in England—i.e., 12% and 35% in those with benign or malignantdiseases, respectively.

Introduction

CLINICIANS have long suspected that there are

differences in the frequency of thromboembolism indifferent geographical regions, with low frequenciesin Asian, Arab, and African populations. A retro-

spective study at this centre has shown that the

frequency of post-partum thromboembolism is muchlower in Thai women than in women studied at theMayo Clinic.2 We have studied the frequency ofthromboembolic complications occurring after majorsurgery in Thai women. Postoperative thrombosiswas determined by the 125I-fibrinogen test and subse-quent phlebography. The results were comparedwith those obtained by the same technique in womenundergoing similar surgery at Oxford. Since identi-cal equipment and the same source of radioactive

fibrinogen (Amersham Radiochemical Centre, U.K.)were used in both studies, and the -people performingthe test in Bangkok were trained in the methodologyat Oxford, the results of the two studies could be

directly compared. 169 women undergoing pelvicsurgery at the Chulalongkorn Hospital Medical. School,Bangkok, were studied.

Patients and Methods

Patients undergoing either total abdominal hysterectomyfor benign conditions or major pelvic surgery for malig-nant disease were admitted to the study. 117 patientsunderwent abdominal hysterectomy for benign conditions,while 52 women were operated on for malignant conditionsof the ovary, uterus, and cervix.

Diagnosis of Leg-vein ThrombosisBefore l2sl_labelled fibrinogen was administered the

uptake of radioactive iodine by the thyroid gland wasblocked by 100 mg. potassium iodide, and this was con-tinued daily for one week. One hour before the operation100 ]Lei of 125I-Iabelled fibrinogen was injected intra-

venously. The level of 125l-labelled fibrinogen activity inthe legs was measured using a Pitman 235 isotope-localisation monitor.3 All measurements were made withthe patients in the supine position with the legs elevatedby 30° to avoid venous pooling of blood and also to allowaccess to the posterior aspect of the calf muscle. Thelimbs were examined four-six hours after operation andon alternate days for seven days. Venous thrombosis wassaid to have occurred when the count had increased by20% when compared to the count at the same spot onthe previous day, and to the count at the correspondingpoint on the opposite limb, providing that the activitypersisted and increased in the next few days. Whenthrombosis was detected by 125I-labelled fibrinogen,percutaneous phlebography was carried out, as describedelsewhere,4 to determine the exact site and extent of thethrombus.

Results

Postoperative D.v.T. was shown to have developedin the legs of 4 (2-4%) of the 169 women who receivedthe radioactive 1251 fibrinogen. None of the positivecases had any clinical signs or symptoms of pulmonaryembolism during the first 7 postoperative days. The

accompanying table compares the results obtained inthis study with results obtained in a similar study atOxford.5 D.V.T. was shown to have developed post-operatively in 2 of the 117 patients with benign con-ditions and 2 of the 52 women with malignant disease.Thrombi were definitely demonstrated in the deepveins of the leg of 1 case by phlebography and notdemonstrated in 2 cases. It was not possible to carryout the procedure in the remaining case.