- Email: [email protected]
Covered expandable metal stent for recurrent tracheal obstruction
582
5.
pressure ventilation through a nose mask. Am Rev Respir Dis 1987; 135: 148-52. Kerby GR, Mayer LS, Pingleton SK. Noctural positive pressure ventilation via nasal mask. Am Rev Respir Dis 1987; 135: 738-40.
6. Bach JR, Alba A, Mosher R, Delaubier A. Intermittent positive pressure ventilation via nasal access in the management of respiratory insufficiency. Chest 1987; 92: 169-70.
Godfrey S, Kamburoff PL, Nairn JR, Connolly NMC, Davis J, Packham E, Samuels CS. Spirometry, lung volumes and airway resistance in normal children aged 5 to 18 years. Br J Dis Chest 1970; 64: 15-24. 8. Segall D. Non-invasive nasal mask-assisted ventilation in respiratory failure of Duchenne muscular dystrophy. Chest 1988; 93: 1299-300. 9. Rideau Y, Gatin G, Bach J, Gines G. Prolongation of life in Duchenne’s muscular dystrophy. Acta Neurol 1983; 38: 118-24. 7.
Covered
10. Bach J, Alba A, Pilkington LA, Lee M. Long-term rehabilitation in advanced stage of childhood onset, rapidly progressive muscular dystrophy. Arch Phys Med Rehab 1981; 62: 328-31. 11. Ellis ER, McCauley VB, Mellis C, Sullivan CE. Treatment of alveolar hypoventilation in a six-year-old girl with intermittent positive pressure ventilation through a nose mask. Am Rev Respir Dis 1987; 136: 188-91. 12. Heckmatt JZ, Loh L, Dubowitz V. Nocturnal hypoventilation in childen with nonprogressive neuromuscular disease. Pediatrics 1989; 83: 250-55. 13. Noble-Jamieson CM, Heckmatt JZ, Dubowitz V, Silverman M. Effects of posture and spinal bracing on respiratory function in neuromuscular disease. Arch Dis Child 1986; 61: 178-81. 14. Newsom Davis J, Goldman M, Loh L, Casson M. Diaphragm function and alveolar hypoventilation. Quart J Med 1976; 45: 87-100.
expandable metal stent for recurrent tracheal obstruction
Rapidly
of recurrent symptoms tumour by may require
obstruction
airways repeated
radiotherapy or endoscopic laser treatment—but these procedures may themselves be distressing. Use of a novel coated metal stent may reduce the frequency with which such palliative intervention is required. Lancet 1990; 335: 582-84.
fibreoptic bronchoscope (Pentax UK, South Harrow, England). Under fluoroscopic control, skin markers were placed on the chest wall
at
the upper and lower borders of
tumour.
The
stent was
compressed and loaded into a hollow delivery catheter and introduced through the rigid bronchoscope. The stent was aligned with the skin markers and released (fig 1). This procedure took approximately 10 min.
Case-report Obstruction of the large airways is an important cause of morbidity and mortality in patients with lung cancer. Symptoms may be relieved by external radiotherapy, but many patients develop recurrent obstruction. In such patients, endoscopic laser treatment1 and endobronchial radiotherapy2,3can be effective, but distressing symptoms may rapidly recur. Use of expandable metal stents4,5 represents an important advance in the management of such patients, but these stents are only suitable for treatment of extrinsic airway compression, and cannot prevent obstruction by intraluminal tumour. We report the successful use of a covered expandable metal stent to treat tracheal obstruction caused by intraluminal tumour.
Methods Endoscopic laser treatments were given under general anaesthesia with a neodymium-yttrium:aluminium:garnet (YAG) laser (’Medilas 2-1-32’, MBB-Medizintechnic, Munich, West Germany) at 10-20 W in pulses of up to 1 s. Both flexible and rigid bronchoscopes were used in a technique similar to that described by Hetzel et al.1 Endobronchial radiotherapy was given 1 week after the first laser treatment. A 137CS source was loaded into a transtracheal catheter which had been guided into the affected airway. Treatment was given for 5 h to deliver 2000 cGy at 05 cm from the source. A ’Gianturco’ stainless steel wire stent (Cook, Bloomington, Indiana, USA)4.5 was covered with material made from nylon and polyvinylchloride. The patient was intubated with a rigid bronchoscope (Karl Storz, Tuttlingen, West Germany) for ventilation and the extent of obstruction was assessed through a
A 60-year-old man was admitted to hospital with extreme breathlessness caused by tumour that obstructed the right main bronchus and lower trachea. A squamous cell carcinoma of the right upper lobe had been diagnosed 1 year previously and had been treated with palliative external radiotherapy. He was thought to be at imminent risk of asphyxia and underwent urgent endoscopic laser treatment which restored full patency to the trachea and right main bronchus with immediate improvement of symptoms and lung function (fig 2). 1 week later, endobronchial radiotherapy was delivered to the involved airway from the lower trachea to the right intermediate bronchus. He remained well for 10 weeks but developed recurrent obstruction within the right main bronchus. Laser treatment was attempted, but was unsuccessful because the obstruction was now caused predominantly by extrinsic compression. 5 weeks later his breathing deteriorated further because of intraluminal tumour growth in the lower trachea. Endoscopic laser resection successfully restored a satisfactory airway but had to be repeated after only 2 weeks when the trachea was again obstructed. After the fourth laser treatment, a covered expandable metal stent was inserted into the lower trachea and orifice to the left main bronchus in the hope that this would provide more prolonged relief. The patient reported no discomfort and led an active and
ADDRESSES Department of Thoracic Medicine, London Chest Hospital, London (P. J. M George, MRCP, J D Irving, FRCR, R M. Rudd, MD), and Radiotherapy Department, London Hospital, London, UK (B. S Mantell, FRCR). Correspondence to Dr P. J M. George, Department of Thoracic Medicine, London Chest Hospital, London E2 9JX, UK.
583
Fig 1-Fluoroscopic views of released (left)
independent life at home for 3 months, with a sustained improvement in lung function (figs 2 and 3). He subsequently became increasingly weak and cachectic and was admitted to hospital for terminal care. 8 days later he died from pneumonia-40 weeks after the first laser treatment, and 15 weeks after insertion of the stent. Bronchoscopy after death showed that the tumour had grown above and below the stent, but the cover was intact and had not been invaded by tumour.
Discussion
Despite endoscopic laser treatment and endobronchial radiotherapy, recurrent tracheal obstruction occurred at increasingly frequent intervals in the patient we describe. Although airway patency and relief of symptoms could probably have been maintained with further laser resections, this would have entailed repeated treatments at progressively shorter intervals-hardly ideal palliative treatment. Longer relief by insertion of a tracheobronchial
and
opened (right) expandable stent.
Silicone rubber stents (T-Y tubes) have been used to manage malignant obstruction of the trachea, main carina, and orifices to both main bronchiand provide effective relief from obstruction caused by intraluminal tumour or extrinsic compression secondary to extraluminal tumour. However, their placement needs considerable expertise and a permanent tracheostomy is required. Expandable metal stents may be inserted more easily and do not require a tracheostomy, but the original stents reported by Wallace et al4 and Simonds and co-workers5 were uncovered and could not prevent recurrent obstruction by intraluminal tumour. However, our use of a novel nylon and polyvinylchloride cover provided effective protection against encroachment upon the airway by intraluminal tumour. Serial flowvolume loops indicate that the lumen of the trachea remained adequately patent for at least 3 months (fig 3),
therefore considered to be the best option for this patient, who had both extrinsic compression and intraluminal tumour. stent was
Fig 3--Flow-volume loops immediately before fourth laser treatment and after stent insertion.
Fig 2-Serial peak expiratory flows from
first laser treatment.
Arrows indicate laser treatments (L), endobronchial radiotherapy (E), and placement of stent (S).
Pretreatment flow-volume loop (top) indicates variable intrathoracic tracheal obstruction; flow-volume loops at 2 (bottom left) and 3 months (bottom right) after stent insertion showed no evidence of obstruction. Axes for bottom flow-volume loops as for top.
584
although
recurrent
tumour grew
tracheal obstruction did
occur
the patient had terminal cachexia and further treatment was not undertaken; otherwise it would have been possible to have restored full airway patency by insertion of additional stents above and below the original. We believe that endoscopic insertion of a covered expandable metal stent provides simple, effective palliation for large airway obstruction caused by both intraluminal and extraluminal tumour, and should help to avoid death by gradual asphyxia in patients with advanced tracheobronchial malignancy.
We thank Cook (Bloomington, Indiana, delivery of the covered expandable stent.
Is
REFERENCES
when
beyond the borders of the stent. By this time,
USA) for rapid construction
and
1. Hetzel MR, Nixon C, Edmonstone WM, et al. Laser therapy in 100 tracheobronchial tumours. Thorax 1985; 40: 341-45. 2. Schray MF, McDougall JC, Martinez A, et al. Management of malignant airway compromise with laser and low dose rate brachytherapy: the Mayo Clinic experience. Chest 1988; 93: 264-69. 3. Macha HN, Koch K, Stadler M, et al. New technique for treating occlusive and stenosing tumours of the trachea and main bronchi: endobronchial irradiation by high dose iridium-192 combined with laser canalisation. Thorax 1987; 42: 511-15. 4. Wallace MJ, Charnsangavej C, Ogawa K, et al. Tracheobronchial tree: expandable metallic stents used in experimental and clinical applications. Radiology 1986; 158: 309-12. 5. Simonds AK, Irving JD, Clarke SW, Dick R. Use of expandable metallic stents in the treatment of bronchial obstruction. Thorax 1989; 44: 680-81. 6. Westaby S, Jackson JW, Pearson FG. A bifurcated silicone rubber stent for relief of tracheobronchial obstruction. J Thorac Cardiovasc Surg 1982; 83: 414-17.
"Campylobacter upsaliensis" an unrecognised cause
of human diarrhoea?
For 3 years a filtration system for the isolation of "new" campylobacter was included in the culture protocol of 15 185 stool specimens. "C upsallensis" was isolated in 99 patients, C jejuni subsp doylei in 4, and C hyointestinalis in 2. "C upsaliensis" was the only organism isolated in 83 patients. Clinical information was available for 77 out of these 83 patients. 92% of the patients had diarrhoea; vomiting and fever were rare (14% and 7%, respectively); the onset was mostly sudden; and the symptoms usually lasted for less than a week. Gross or occult blood was present in a quarter of cases and neutrophils were detected in faecal smears in about a fifth. "C upsaliensis" may be an unrecognised and frequent cause of diarrhoea in man, and selective isolation media should be combined with non-selective isolation systems. Lancet 1990; 335: 584-86.
Introduction
Catalase-negative or catalase-weak (CNW) strains of campylobacter were first isolated from dogs, both with and without diarrhoea.1 DNA hybridisation studies showed that these strains were members of a previously undescribed Campylobacter sp. The name "C upsaliensis" was proposed for the CNW group.2 The role of this organism as a pathogen in man is controversial. Several groups have reported on the association of "C upsaliensis" with
diarrhoea3-{; and bacteraemia. We provide additional evidence about "C upsaliensis" and diarrhoea in man.
Materials and methods The campylobacter-selective media used routinely in our laboratory were: (i) BMV, a solid blood-based medium (Virion AG, Zurich), containing cefoperazone (30 mg/1), rifampicin (10 mg/1), and amphotericin B (2 mg/1), (ii) CCDA, a solid blood-free basal medium CDA (Oxoid CM739, Basingstoke, UK), containing cefoperazone (32 mg/1) ;9 and (iii) a semi-solid medium containing cefoperazone (30 mg/1) and trimethoprim (50 mg/1)." We also included a filtration systemll in which a cellulose triacetate membrane filter (diameter 47 mm) was placed on Mueller-Hinton agar (Oxoid) with 5% sheep blood prepared in small petri dishes. Initially, from July 1, 1986, to Jan 31, 1987, we used filters with a pore size of 0-65 (im (Gelman, Michigan); however, because of a high rate of contamination with faecal flora (12% of the plates), we decided to use 0 45 pm filters (Oxoid). Clinical data were collected retrospectively and prospectively. The appearance of the stools was noted, and the presence of leucocytes and erythrocytes in the stools was evaluated by Giemsa
stain.
ADDRESSES
WHO Collaborating Centre for Enteric Campylobacter, St Pieters University Hospital, Brussels (H. Goossens, MD, L. Vlaes, M. De Boeck, J. Levy, MD, P. De Mol, MD, Prof J.-P. Butzler, MD,); and Laboratory for Microbiology and Microbial Genetics, Rijksuniversiteit, Gent, Belgium (Prof K. Kersters, MD, B.Pot, BSc, P. Vandamme, BSc). Correspondence to Dr H. Goossens, Laboratorium voor Microbiologie, St Pieters University Hospital, 322 Hoogstraat, B-1000 Brussels, Belgium.
5.
pressure ventilation through a nose mask. Am Rev Respir Dis 1987; 135: 148-52. Kerby GR, Mayer LS, Pingleton SK. Noctural positive pressure ventilation via nasal mask. Am Rev Respir Dis 1987; 135: 738-40.
6. Bach JR, Alba A, Mosher R, Delaubier A. Intermittent positive pressure ventilation via nasal access in the management of respiratory insufficiency. Chest 1987; 92: 169-70.
Godfrey S, Kamburoff PL, Nairn JR, Connolly NMC, Davis J, Packham E, Samuels CS. Spirometry, lung volumes and airway resistance in normal children aged 5 to 18 years. Br J Dis Chest 1970; 64: 15-24. 8. Segall D. Non-invasive nasal mask-assisted ventilation in respiratory failure of Duchenne muscular dystrophy. Chest 1988; 93: 1299-300. 9. Rideau Y, Gatin G, Bach J, Gines G. Prolongation of life in Duchenne’s muscular dystrophy. Acta Neurol 1983; 38: 118-24. 7.
Covered
10. Bach J, Alba A, Pilkington LA, Lee M. Long-term rehabilitation in advanced stage of childhood onset, rapidly progressive muscular dystrophy. Arch Phys Med Rehab 1981; 62: 328-31. 11. Ellis ER, McCauley VB, Mellis C, Sullivan CE. Treatment of alveolar hypoventilation in a six-year-old girl with intermittent positive pressure ventilation through a nose mask. Am Rev Respir Dis 1987; 136: 188-91. 12. Heckmatt JZ, Loh L, Dubowitz V. Nocturnal hypoventilation in childen with nonprogressive neuromuscular disease. Pediatrics 1989; 83: 250-55. 13. Noble-Jamieson CM, Heckmatt JZ, Dubowitz V, Silverman M. Effects of posture and spinal bracing on respiratory function in neuromuscular disease. Arch Dis Child 1986; 61: 178-81. 14. Newsom Davis J, Goldman M, Loh L, Casson M. Diaphragm function and alveolar hypoventilation. Quart J Med 1976; 45: 87-100.
expandable metal stent for recurrent tracheal obstruction
Rapidly
of recurrent symptoms tumour by may require
obstruction
airways repeated
radiotherapy or endoscopic laser treatment—but these procedures may themselves be distressing. Use of a novel coated metal stent may reduce the frequency with which such palliative intervention is required. Lancet 1990; 335: 582-84.
fibreoptic bronchoscope (Pentax UK, South Harrow, England). Under fluoroscopic control, skin markers were placed on the chest wall
at
the upper and lower borders of
tumour.
The
stent was
compressed and loaded into a hollow delivery catheter and introduced through the rigid bronchoscope. The stent was aligned with the skin markers and released (fig 1). This procedure took approximately 10 min.
Case-report Obstruction of the large airways is an important cause of morbidity and mortality in patients with lung cancer. Symptoms may be relieved by external radiotherapy, but many patients develop recurrent obstruction. In such patients, endoscopic laser treatment1 and endobronchial radiotherapy2,3can be effective, but distressing symptoms may rapidly recur. Use of expandable metal stents4,5 represents an important advance in the management of such patients, but these stents are only suitable for treatment of extrinsic airway compression, and cannot prevent obstruction by intraluminal tumour. We report the successful use of a covered expandable metal stent to treat tracheal obstruction caused by intraluminal tumour.
Methods Endoscopic laser treatments were given under general anaesthesia with a neodymium-yttrium:aluminium:garnet (YAG) laser (’Medilas 2-1-32’, MBB-Medizintechnic, Munich, West Germany) at 10-20 W in pulses of up to 1 s. Both flexible and rigid bronchoscopes were used in a technique similar to that described by Hetzel et al.1 Endobronchial radiotherapy was given 1 week after the first laser treatment. A 137CS source was loaded into a transtracheal catheter which had been guided into the affected airway. Treatment was given for 5 h to deliver 2000 cGy at 05 cm from the source. A ’Gianturco’ stainless steel wire stent (Cook, Bloomington, Indiana, USA)4.5 was covered with material made from nylon and polyvinylchloride. The patient was intubated with a rigid bronchoscope (Karl Storz, Tuttlingen, West Germany) for ventilation and the extent of obstruction was assessed through a
A 60-year-old man was admitted to hospital with extreme breathlessness caused by tumour that obstructed the right main bronchus and lower trachea. A squamous cell carcinoma of the right upper lobe had been diagnosed 1 year previously and had been treated with palliative external radiotherapy. He was thought to be at imminent risk of asphyxia and underwent urgent endoscopic laser treatment which restored full patency to the trachea and right main bronchus with immediate improvement of symptoms and lung function (fig 2). 1 week later, endobronchial radiotherapy was delivered to the involved airway from the lower trachea to the right intermediate bronchus. He remained well for 10 weeks but developed recurrent obstruction within the right main bronchus. Laser treatment was attempted, but was unsuccessful because the obstruction was now caused predominantly by extrinsic compression. 5 weeks later his breathing deteriorated further because of intraluminal tumour growth in the lower trachea. Endoscopic laser resection successfully restored a satisfactory airway but had to be repeated after only 2 weeks when the trachea was again obstructed. After the fourth laser treatment, a covered expandable metal stent was inserted into the lower trachea and orifice to the left main bronchus in the hope that this would provide more prolonged relief. The patient reported no discomfort and led an active and
ADDRESSES Department of Thoracic Medicine, London Chest Hospital, London (P. J. M George, MRCP, J D Irving, FRCR, R M. Rudd, MD), and Radiotherapy Department, London Hospital, London, UK (B. S Mantell, FRCR). Correspondence to Dr P. J M. George, Department of Thoracic Medicine, London Chest Hospital, London E2 9JX, UK.
583
Fig 1-Fluoroscopic views of released (left)
independent life at home for 3 months, with a sustained improvement in lung function (figs 2 and 3). He subsequently became increasingly weak and cachectic and was admitted to hospital for terminal care. 8 days later he died from pneumonia-40 weeks after the first laser treatment, and 15 weeks after insertion of the stent. Bronchoscopy after death showed that the tumour had grown above and below the stent, but the cover was intact and had not been invaded by tumour.
Discussion
Despite endoscopic laser treatment and endobronchial radiotherapy, recurrent tracheal obstruction occurred at increasingly frequent intervals in the patient we describe. Although airway patency and relief of symptoms could probably have been maintained with further laser resections, this would have entailed repeated treatments at progressively shorter intervals-hardly ideal palliative treatment. Longer relief by insertion of a tracheobronchial
and
opened (right) expandable stent.
Silicone rubber stents (T-Y tubes) have been used to manage malignant obstruction of the trachea, main carina, and orifices to both main bronchiand provide effective relief from obstruction caused by intraluminal tumour or extrinsic compression secondary to extraluminal tumour. However, their placement needs considerable expertise and a permanent tracheostomy is required. Expandable metal stents may be inserted more easily and do not require a tracheostomy, but the original stents reported by Wallace et al4 and Simonds and co-workers5 were uncovered and could not prevent recurrent obstruction by intraluminal tumour. However, our use of a novel nylon and polyvinylchloride cover provided effective protection against encroachment upon the airway by intraluminal tumour. Serial flowvolume loops indicate that the lumen of the trachea remained adequately patent for at least 3 months (fig 3),
therefore considered to be the best option for this patient, who had both extrinsic compression and intraluminal tumour. stent was
Fig 3--Flow-volume loops immediately before fourth laser treatment and after stent insertion.
Fig 2-Serial peak expiratory flows from
first laser treatment.
Arrows indicate laser treatments (L), endobronchial radiotherapy (E), and placement of stent (S).
Pretreatment flow-volume loop (top) indicates variable intrathoracic tracheal obstruction; flow-volume loops at 2 (bottom left) and 3 months (bottom right) after stent insertion showed no evidence of obstruction. Axes for bottom flow-volume loops as for top.
584
although
recurrent
tumour grew
tracheal obstruction did
occur
the patient had terminal cachexia and further treatment was not undertaken; otherwise it would have been possible to have restored full airway patency by insertion of additional stents above and below the original. We believe that endoscopic insertion of a covered expandable metal stent provides simple, effective palliation for large airway obstruction caused by both intraluminal and extraluminal tumour, and should help to avoid death by gradual asphyxia in patients with advanced tracheobronchial malignancy.
We thank Cook (Bloomington, Indiana, delivery of the covered expandable stent.
Is
REFERENCES
when
beyond the borders of the stent. By this time,
USA) for rapid construction
and
1. Hetzel MR, Nixon C, Edmonstone WM, et al. Laser therapy in 100 tracheobronchial tumours. Thorax 1985; 40: 341-45. 2. Schray MF, McDougall JC, Martinez A, et al. Management of malignant airway compromise with laser and low dose rate brachytherapy: the Mayo Clinic experience. Chest 1988; 93: 264-69. 3. Macha HN, Koch K, Stadler M, et al. New technique for treating occlusive and stenosing tumours of the trachea and main bronchi: endobronchial irradiation by high dose iridium-192 combined with laser canalisation. Thorax 1987; 42: 511-15. 4. Wallace MJ, Charnsangavej C, Ogawa K, et al. Tracheobronchial tree: expandable metallic stents used in experimental and clinical applications. Radiology 1986; 158: 309-12. 5. Simonds AK, Irving JD, Clarke SW, Dick R. Use of expandable metallic stents in the treatment of bronchial obstruction. Thorax 1989; 44: 680-81. 6. Westaby S, Jackson JW, Pearson FG. A bifurcated silicone rubber stent for relief of tracheobronchial obstruction. J Thorac Cardiovasc Surg 1982; 83: 414-17.
"Campylobacter upsaliensis" an unrecognised cause
of human diarrhoea?
For 3 years a filtration system for the isolation of "new" campylobacter was included in the culture protocol of 15 185 stool specimens. "C upsallensis" was isolated in 99 patients, C jejuni subsp doylei in 4, and C hyointestinalis in 2. "C upsaliensis" was the only organism isolated in 83 patients. Clinical information was available for 77 out of these 83 patients. 92% of the patients had diarrhoea; vomiting and fever were rare (14% and 7%, respectively); the onset was mostly sudden; and the symptoms usually lasted for less than a week. Gross or occult blood was present in a quarter of cases and neutrophils were detected in faecal smears in about a fifth. "C upsaliensis" may be an unrecognised and frequent cause of diarrhoea in man, and selective isolation media should be combined with non-selective isolation systems. Lancet 1990; 335: 584-86.
Introduction
Catalase-negative or catalase-weak (CNW) strains of campylobacter were first isolated from dogs, both with and without diarrhoea.1 DNA hybridisation studies showed that these strains were members of a previously undescribed Campylobacter sp. The name "C upsaliensis" was proposed for the CNW group.2 The role of this organism as a pathogen in man is controversial. Several groups have reported on the association of "C upsaliensis" with
diarrhoea3-{; and bacteraemia. We provide additional evidence about "C upsaliensis" and diarrhoea in man.
Materials and methods The campylobacter-selective media used routinely in our laboratory were: (i) BMV, a solid blood-based medium (Virion AG, Zurich), containing cefoperazone (30 mg/1), rifampicin (10 mg/1), and amphotericin B (2 mg/1), (ii) CCDA, a solid blood-free basal medium CDA (Oxoid CM739, Basingstoke, UK), containing cefoperazone (32 mg/1) ;9 and (iii) a semi-solid medium containing cefoperazone (30 mg/1) and trimethoprim (50 mg/1)." We also included a filtration systemll in which a cellulose triacetate membrane filter (diameter 47 mm) was placed on Mueller-Hinton agar (Oxoid) with 5% sheep blood prepared in small petri dishes. Initially, from July 1, 1986, to Jan 31, 1987, we used filters with a pore size of 0-65 (im (Gelman, Michigan); however, because of a high rate of contamination with faecal flora (12% of the plates), we decided to use 0 45 pm filters (Oxoid). Clinical data were collected retrospectively and prospectively. The appearance of the stools was noted, and the presence of leucocytes and erythrocytes in the stools was evaluated by Giemsa
stain.
ADDRESSES
WHO Collaborating Centre for Enteric Campylobacter, St Pieters University Hospital, Brussels (H. Goossens, MD, L. Vlaes, M. De Boeck, J. Levy, MD, P. De Mol, MD, Prof J.-P. Butzler, MD,); and Laboratory for Microbiology and Microbial Genetics, Rijksuniversiteit, Gent, Belgium (Prof K. Kersters, MD, B.Pot, BSc, P. Vandamme, BSc). Correspondence to Dr H. Goossens, Laboratorium voor Microbiologie, St Pieters University Hospital, 322 Hoogstraat, B-1000 Brussels, Belgium.