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B19 virus is a single-strand DNA virus, theoretically our method can detect approximately 40 copies of B19 DNA. The pre-treatment B19 viral load was roughly 431010 copies per 10 ml plasma (dilution fold 109 3 detection limit 40 copies) in our patient. There was a rapid decline of serum B19 DNA copies initially after IVIG therapy. A 5 log10 decrease of B19 genome copies occurred on the second day of IVIG treatment and followed by an additional 2 log10 decrease on the fourth day of IVIG treatment (Fig. 1). The B19 DNA continued to be cleared from circulation but with a slower rate after day 4 and was about 40 000 copies per ml plasma on the 13th day (29 April). The B19 viral load increased to the pre-treatment level on 28 August, 6 weeks prior to recurrence of anaemia.
the time ranged from 5 to 7 months.1,2 Monthly maintenance IVIG therapy had been proposed for AIDS patients with persistent B19 infection.2 Due to the long lifetime of red blood cells, we noted that the B19 viral load returned to pre-treatment level 6 weeks before the relapse of anaemia. Therefore, the interval of maintenance IVIG treatment could be determined by monitoring B19 viral load monthly. In the era of highly active anti-retroviral therapy, AIDS patients with persistent B19 infection no longer required maintenance therapy.8,9 However AIDS patients with treatment failure or patients with primary immunodeficiency4 may still need maintenance IVIG to control persistent infection. The measurement of B19 viral load can help to individualize maintenance IVIG therapy and may reduce the cost of treatment.
Discussion
References
The method of PCR and end-point dilution to measure the B19 viral load is simple and easy to perform. However, the sensitivity of this method may be influenced by several factors. First, certain amount of B19 DNA may be lost during extraction. Second, the dilution procedure may be subjected to error. Third, the possible existence of inhibitors in plasma may hinder PCR. Fourth, PCR performed on different days may have difference in sensitivity. We had repeated the sensitivity study on different occasions and the detection limit lied in a small range from 10–30 molecules. To determine the impact of plasma inhibitors, parallel sensitivity study with or without adding DNA extracted from 3 ml of B19 negative plasma to each PCR tube was done. The detection limit in the absence or presence of plasma extract was 10 and 30 molecules, respectively. Therefore, it is unlikely that the inhibitors will be a problem. The result of semi-quantitative PCR is reproducible if the whole procedure is done with extra care. The reported clearance rate of circulating B19 DNA was very rapid after administration of IVIG.1 We found similar result by using the semi-quantitative PCR method. The nadir of B19 viral load in our patient was below the reported range of 105 to 107 per ml serum, however, different method was used to measure viral load. Although our patient and patients reported in literature had very low CD4 cell count, the function of phagocytic cells seemed to be intact because of the rapid clearance of B19. Difference in residual B19 viral load could be due to various titer of neutralizing anti-B19 antibodies contained in IVIG. AIDS patients who received IVIG 2 g/kg had longer period of remission than those who were treated with IVIG 1 g/kg.2 The duration of remission varied among AIDS patients but most of
1 Frickhofen N, Abkowitz JL, Safford M et al. Persistent B19 parvovirus infection in patients infected with human immunodeficiency virus type 1 (HIV-1): a treatable cause of anaemia in AIDS. Ann Intern Med 1990; 113: 926–932. 2 Koduri PR, Kumapley R, Valladares J, Teter C. Chronic pure red cell aplasia caused by parvovirus B19 in AIDS: use of intravenous immunoglobulin – A report of eight patients. Am J Hematol 1999; 61: 16–20. 3 Kurtzman G, Frickhofen N, Kimball J, Jenkins DW, Nienhuis AW, Young NS. Pure red-cell aplasia of 10 years’ duration due to persistent parvovirus B19 infection and its cure with immunoglobulin therapy. N Engl J Med 1989; 321: 519–523. 4 Tang MLK, Kemp AS, Moaven LD. Parvovirus B19-associated red blood cell aplasia in combined immunodeficiency with normal immunoglobulins. Pediatr Infect Dis J 1994; 13: 539–542. 5 Koch WC, Massey G, Russell CE, Adler SP. Manifestations and treatment of human parvovirus B19 infection in immunocompromised patients. J Pediatr 1990; 116: 355–359. 6 Young NS. Parvovirus infection and its treatment. Clin Exp Immunol 1996; 104(Suppl. 1): 26–30. 7 Shade RO, Blundell MC, Cotmore SF et al. Nucleotide sequence and genome organization of human parvovirus B19 isolated from the serum of a child during aplastic crisis. J Virol 1986; 58: 921–936. 8 Chen MY, Hung CC, Fan CT, Hsieh SM. The reconstituted immunity against persistent parvovirus B19 infection in an AIDS patient after highly active antiretroviral treatment. Clin Infect Dis 2001; 32: 1361–1365. 9 Mylonakis E, Dickinson BP, Mileno MD, Flanigan T, Schiffman FJ, Mega A, Rich JD. Persistent parvovirus B19 related anemia of seven years’ duration in an HIV-infected patient: Complete remission associated with highly active antiretroviral therapy. Am J Hematol 1999; 60: 164–166.
doi:10.1053/jinf.2001.0870, available online at http://www.idealibrary.com on
Infections caused by Gemella spp.: Case Reports from India R. Chaudhry*1, P. Mathur1, B. Dhawan1, S. Gaur1 and A. B. Dey2 Departments of 1Microbiology and 2Medicine, All India Institute of Medical Sciences, New Delhi, India Human infections caused by Gemella spp. are rare. We report here our experience of the isolation of species of Gemellae from various clinical samples. Careful and complete identification of this organism will prevent diagnostic and therapeutic delays and bring more such cases to light. © 2001 The British Infection Society
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Case Three
Members of the genus Gemella consist of catalase negative, facultatively anaerobic, Gram-positive cocci which occur in pairs (often with adjacent sides flattened), tetrads and short chains and possess DNA with a low G C content. Five species, Gemella haemolysans, Gemella morbillorum, Gemella bergeriae, Gemella sanguinis and Gemella palaticanis have been described to date. G. haemolysans and G. morbillorum are residents of the mucous membranes of human and some other animals.1,2 G. sanguinis and G. bergeriae have been recently described from human sources,3,4 while G. palaticanis has been described from a dog.5 In healthy people, G. haemolysans has been found in the oral cavity6 whereas G. morbillorum is in addition found as a component of the normal human intestinal flora. Gemellae, like some other commensal bacterial of the human microbiota, are opportunistic pathogens, causing severe localized and generalized infections in immunocompromised as well as immunocompetent hosts. We have previously reported a case of septicaemia in an immunocompromised patient due to G. morbillorum. Recently, we had the opportunity to diagnose another three cases of infections due to Gemella spp. which presented within a period of 1 year. These cases highlight the diverse clinical spectrum of infections caused by this organism. We present here the details of these cases.
A 10-year-old boy presented with fever, breathlessness, joint pains and oliguria. He gave a history of sore throat six months previously. Fever was intermittent over a period of 1 month, associated with anorexia and weight loss. On examination, the patient was sweating and afebrile, with bilateral pedal oedema, periorbital swelling, splenic enlargement and ascites. The patient was in congestive cardiac failure with a diastolic murmur characteristic of aortic incompetence. Clubbing was present. Splinter haemorrhages were not detected. Laboratory investigations showed haemoglobin 11.6 g/dl, ESR 40 mm/1st hour, white blood cell count 8.6 109/1 (90% neutrophils) and antistreptolysin 0 titre of 200 IU. Echocardiogram showed aortic and mitral incompetence, suggesting a diagnosis of rheumatic heart disease with aortic and mitral regurgitation, pulmonary artery hypertension and valvular dysfunction. After valve replacement, the wound site on the chest discharged pus, which was sent for bacterial culture. A pure culture of an alpha haemolytic Gram-positive cocci was obtained and identified by standard procedures. The patient received cephalexin (250 mg every 6 h.) for a total of 2 weeks after which the wound healed.
Case One
Bacteriology
A 12-year-old boy, with congenital cyanotic heart disease diagnosed at the age of 3 years, was admitted to hospital after an episode of seizures. On examination, he was cyanosed and irritable with pulse 90/min and blood pressure of 130/80 mmHg. Bilateral papilloedema and signs of raised intracranial tension were present. Computed tomography (CT) of the brain showed a right temporal multiloculated abscess with mass effect and a left midline shift. Laboratory investigations revealed a leukocyte count of 9.0 109/1 (85% neutrophils) and haemoglobin of 11.8 g/dl. Echocardiography showed no significant findings. A right temporal burr hole was made with aspiration of about 60 ml of thick, foul smelling pus. A pure growth of alpha haemolytic Gram-positive cocci was obtained from culture of the pus, preliminarily identified as a viridans group Streptococcus. Post-operative intravenous penicillin and gentamicin was initiated and the patient recovered completely.
All the isolates showed ovoid, Gram-positive cocci, arranged singly or in pairs. They were catalase negative, oxidase negative, facultative anaerobes which produced small, alpha haemolytic colonies on 5% sheep blood agar. Growth was better under 5% CO2 incubation. The isolates did not grow in broth containing 6.5% NaCl, at 10 or 45 C, and were relatively biochemically inert (Table I). They were identified by conventional biochemical tests,7±9 and further biochemically characterized by using the API 20 STREP system (bioMereux, U.K.) according to the manufacturer's instructions. Cases one and two were confirmed as G. morbillorum and case three as G. haemolysans. They were differentiated from G. bergeriae on the basis of production of acid from maltose and sucrose,4 and from G. sanguinis by negative mannitol and sorbitol fermentation and lack of alkaline and acid phosphatase production.3 The isolates did not produce pyrrolidonyl arylamidase or arginine dihydrolase, which differentiated them from Dolosigranulum spp. All three isolates were sensitive to benzylpenicillin, ampicillin, cephelexin, gentamicin, vancomycin and ciprofloxacin by the standard Kirby±Bauer sensitivity test. The MIC to penicillin was 0.12 mg/ml, vancomycin 1 mg/ml and chloramphenicol 4 mg/ml by the E-test method.
Case Two A 20-year-old man presented with a swelling on the left half of the palate and poor oral hygiene. A pure growth of an alpha haemolytic Gram-positive cocci was obtained from pus culture and identified according to standard procedures. Antibiotic therapy with amoxycillin was continued for a period of 1 week following which the swelling slowly subsided.
*Please address all correspondence to: Dr. Rama Chaudhry, Department of Microbiology, All India Institute of Medical Sciences. New Delhi110 029, India. Fax: 91-11-6862663; E-mail:
[email protected] or
[email protected] Accepted for publication 6 July 2001.
Conclusions As ``opportunistic pathogens,'' gemellae are able to cause severe localized and generalized infections. Among reported Gemella infections, most are endocarditis, usually associated with previous valvular damage and poor dental state. In a study of 52 cases of ``Streptococcal'' endocarditis, gemellae represented 6% of the ``viridans group streptococci'' and 5% of all isolates.11 Central nervous system and skeletal infections have also been described.12,13 In our first case, G. morbillorum was isolated from a brain abscess in a patient with cyanotic heart disease. A Medline search for reports of brain abscess due to Gemella spp. from # 2001 The British Infection Society
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Case Reports Table I. Biochemical characterization of strains isolated in this study. Biochemicals
Voges Proskauer Alkaline phosphatase Acid phosphatase Pyrrolidonyl arylamidase Leucine aminopeptidase Esculin hydrolysis Hippurate hydrolysis Gelatin hydrolysis Acid from Glucose Acid from Sucrose Acid from Lactose Acid from Maltose Acid from Mannitol Acid from Mannose Acid from Trehalose Acid from Ribose Acid from L-Arabinose Acid from Sorbitol Acid from Inulin Acid from Raffinose Acid from Glycogen Acid from Starch Acid from Mellibiose Acid from D-xylose Arginine dihydrolase galactosidase galactosidase Urease
Case 1 G. morbillorum
Case 2 G. morbillorum
Case 3 G. haemolysans
ÿ ÿ ÿ ÿ + ÿ ÿ ÿ + + ÿ + ÿ ÿ + ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ
ÿ ÿ ÿ ÿ + ÿ ÿ ÿ + + ÿ + ÿ + ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ
+ ÿ ÿ ÿ + ÿ ÿ ÿ + + ÿ + ÿ ÿ + ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ ÿ
1990 to 1999 revealed only one case, where the predisposing factor was sinusitis. Meningitis, subdural empyema and intracerebral abscesses are rare intracranial complications of sinusitis. In our case, cyanotic heart disease leading to chronic oxygen desaturation and polycythaemia may be the facilitating factor for cerebritis, focal encephalomalacia and brain abscess. Since the organism was recovered in a pure growth and the patient responded to antibiotic therapy after drainage of pus, G. morbillorum appears to be the only aetiological agent in this case. In the second case, poor oral hygiene may have led to the localized palatal abscess due to G. morbillorum. Retropharyngeal abscess due to G. morbillorum has been previously reported14,15 leading to meningitis in one case,14 but palatal abscess has not been reported. In the third case, wound infection due to G. haemolysans was diagnosed in a patient who had valvular surgery. G. haemolysans was until recently considered to be a harmless commensal of the upper respiratory tract, carried by approximately 30% of healthy young adults.6 However, in the last decade, there have been reports of septicaemia, endocarditis and meningitis due to G. haemolysans indicating the clinical relevance of this organism.12,16,17 Most isolates of G. haemolysans are highly susceptible to penicillin. However, isolates with reduced sensitivity to penicillin (MIC 0.5 mg/l) and resistance to vancomycin (> 32 mg/C), teicoplanin, erythromycin and tetracyline have been reported.17 Our isolates were sensitive to all routinely used antimicrobials. These cases illustrate the need to identify G. haemolysans and its antimicrobial susceptibility pattern.
We have previously reported bacteremia due to G. morbillorum in a 9-year-old immunocompromised boy with neuroblastoma.18 The isolation of Gemella spp. from previously healthy, immunocompetent individuals emphasises the pathogenic potential of this organism. We believe that full identification of Gemella spp. could prevent diagnostic and therapeutic delays and bring more cases to light. During gram staining, cells may be easily decolourized and may therefore appear to be Gram variable and even Gram negative. It is likely that variable gram staining and morphological polymorphism are responsible for the misidentification of Gemella spp., and may explain why few cases of Gemella infection are reported.11 Gemella spp., may sometimes be incorrectly identified as viridans groups streptococci.19 Our cases suggest that the pathogenicity and clinical significance of Gemella spp. should not be under estimated. Prompt appropriate treatment will usually lead to a favourable outcome.
Acknowledgement We acknowledge the help of Dr P. Panigrahi, Dept. of Pediatrics, University of Maryland, U.S.A., for providing the API20 STREP System and Mr Madho Prasad for technical assistance.
References 1 Berger V. A proposed New genus of gram-negative cocci: Gemella. Int Bull Bacteriol Nomencl Taxon 1961; 11: 17±19.
Case Reports 2 Berger U. The genus Gemella. In: Balows A, Touper HG, Workin MD, Harder W, Schliefer KH (ed.) The Prokaryotes 2nd edn. New York: Springer Verlag, 1992; pp. 1643±1653. 3 Collins MD, Hutson R, Faisen E, Sjoden B, Facklam R. Description of Gemella sanguinis Sp. Nov., isolated from human clinical specimens. J Clin Microbial 1998; 36: 3090±3093. 4 Collins MD, Hutson R, Faisen E, Sjoden B, Facklam R. Gemella bergeriae Sp. Nov., isolated from human clinical specimens. J Clin Mibrobial 1998; 36: 1290±1293. 5 Collins MD, Rodriguez J.M., Faster G. Sjoden B, Falsen E. Characterization of a gemella-like organism from the oral cavity of a dog; description of Gemella palaticanis Sp. Nov. Int J Syst Bact 1999; 49: 1523±1526. 6 Berger U. Prevalence of Gemella haemolysans on the pharyngeal mucosa of man. Med Microbiol Immunol (Berl.) 1985; 174: 267±274. 7 Collee JG, Miles RS, Watt B. Tests for the identification of bacteria. In: Collee JG, Fraser AG, Marmion BP, Simmons A (eds). Mackie and McCartney. Practical Medical Microbiology, 14th edn. New York: Churchill Livingstone, 1996; pp. 131±145. 8 Forbes BA, Sahm DF, Weissfeld AS. Bailey and Scott's Diagnostic Microbiology, 10th edn. St. Louis: Mosby, 1998. 9 Facklam R, Elliot JA. Identification, classification and clinical relevance of catalase-negative, Gram positive cocci, excluding streptococci and enterococci. Clin Microbial Rev 1995; 8: 479±495. 10 Aguirre M, Morrison D, Cookson BD, Gay FW, Collins MD. Phenotypic and phylogenetic characterization of some Gemella like organisms from human Infection: description of Dolosigranulum pigrum gen. Nov., Sp. Nov. J Appl Bacteriol 1993; 73: 608±612.
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11 LaScola B, Raoult D. Molecular identification of Gemella species from three patients with endocarditis. J Clin Microbiol 1998; 36: 866± 871. 12 Aspevall O., Hillebrandt E., Linderoth B. and Rylander M. Meningitis due to Gemella haemolysans after neurosurgical treatment of trigeminal neuralgia. Scand J Infect Dis 1991; 23: 503±505. 13 Omran Y, Wood CA. Endovascular infection and septic arthritis caused by Gemella morbillorum. Diagn Microbiol Infect Dis 1993; 16: 131±134. 14 Tokuoka K, Hamano H, Ohta T, Tamura Y, Shinohara Y. An adult case of purulent meningitis secondary to retropharyngeal and deep neck abscess after treatment of odontogenic infection. Rinsho Shinkeigaku 1997; 37: 417±419. (Japanese.) 15 Pradeep R, Ali M, Encarnacion CF. Retropharyngeal abscess due to G.morbillorum CID 1997; 24: 284±285. 16 Helft G, Tabone X, Metzer JP, Vacheron A. Gemella haemolysans endocarditis with colonic carcinoma. Eur J Med 1993; 2: 369±370. 17 Reed C, Efstratiou H, Morrisson AD, Woodford N. Glycopeptide resistant Gemella haemolysans from blood. Lancet 1993; 342: 927± 928. 18 Mathur P, Dhawan B, Kumar L, Arya LS, Chaudhry R. Bacteremia due to Gemella morbillorum. Indian Pediatr 1999; 36: 1264±1266. 19 Ruoff KL. Gemella: a tale of two new species (and five genera). Clin Microbial Newsl 1990; 12: 1±4.
doi:10.1053/jinf.2001.0873, available online at http://www.idealibrary.com on
Spontaneous Bacterial Peritonitis and Bacteraemia due to Leuconostoc Species in a Patient with End-stage Liver Disease: A Case Report K. S. Templin1, T. Crook* 2, T. Riley III3, C. Whitener2 and R. C. Aber2 1
Department of Medicine, 2Division of Infectious Diseases and 3Division of Gastroenterology, Penn State College of Medicine, The Milton S. Hershey Center, 500 University Drive, Hershey, Pennsylvania, U.S.A. This report describes a case of spontaneous bacterial peritonitis in a patient with end stage liver disease in whom Leuconostoc spp. was isolated from blood and ascitic fluid. In common with several previously described patients with cultures positive for Leuconostoc from other body sites, this patient had recently received vancomycin. The antibiotic susceptibilities and mechanism of vancomycin resistance of this Gram-positive bacteria are reviewed. # 2001 The British Infection Society
INTRODUCTION Leuconostoc spp. are Gram-positive facultative anaerobic cocci or coccobacilli, that are not part of the usual human flora but found commonly in dairy products, legumes and vegetables, as well as in the wine and pickling industries. Until 1985 Leuconostoc spp. were not thought to be pathogenic to humans, but over the past 15 years there have been occasional reports of
infections in patients with underlying immune defects,1,2 and in otherwise healthy individuals.3 All Leuconostoc spp. are intrinsically resistant to vancomycin due to the structure of their cell wall precursors. Leuconostoc spp. have been isolated from blood, pleural, and bronchoalveolar fluid,4,5 as well as bone,6 urine,7 and cerebrospinal fluid.8 To our knowledge we describe the first reported case in which Leuconostoc spp. was cultured from ascitic fluid.