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Cross-recognition of aspergillus galactomannan caused by Listeria monocytogenes infection
Diagnostic Microbiology and Infectious Disease 76 (2013) 250–251
Contents lists available at SciVerse ScienceDirect
Diagnostic Microbiology and Infectious Disease journal homepage: www.elsevier.com/locate/diagmicrobio
Cross-recognition of aspergillus galactomannan caused by Listeria monocytogenes infection☆ Maria Concetta Petti a, Grazia Prignano b, Andrea Mengarelli a, Antonio Spadea a, Laura Cilli b, Corrado Girmenia c,⁎ a b c
Department of Hematology, Regina Elena National Cancer Institute, Rome, Italy Clinical Pathology and Microbiology Laboratory, San Gallicano Dermatology Institute, Rome, Italy Department of Hematology, Azienda Policlinico Umberto I, Rome, Italy
a r t i c l e
i n f o
Article history: Received 28 December 2012 Received in revised form 11 February 2013 Accepted 12 February 2013 Available online 19 March 2013
a b s t r a c t We report a case of Listeria monocytogenes bacteremia in a leukemic patient having a positive assay for aspergillus galactomannan (GM), although no evidence of aspergillosis was found. Supernatant obtained from L. monocytogenes strain suspension was reactive with GM-assay. L. monocytogenes produces a soluble antigen that is cross-reactive with Aspergillus GM. © 2013 Elsevier Inc. All rights reserved.
Keywords: Listeria monocytogenes Galactomannan Cross-reaction
Aspergillus galactomannan (GM) detection by Platelia® assay has been introduced among the microbiologic criteria for the diagnosis of invasive aspergillosis (IA) (de Pauw et al., 2008). A major problem with the detection of circulating GM is the occurrence of false-positive results, which, in some cases, have been shown to be related to a cross-recognition of non-Aspergillus pathogens such as Fusarium spp, Penicillium species, and Geotrichum capitatum (Bonini et al., 2008; Huang et al., 2007; Mennink-Kersten et al., 2004a; Tortorano et al., 2012). We describe the case of a positive GM assay in a leukemic patient with Listeria monocytogenes bacteremia. A 61-year-old man with an acute myeloid leukemia underwent a salvage treatment with fludarabine, idarubicine and cytosinearabinoside after failure of first induction chemotherapy which had not been complicated by any infection. Oral ciprofloxacin and posaconazole prophylaxis were administered during neutropenia. Clinical and microbiologic assessment during the period following chemotherapy are detailed in Fig. 1. The patient developed a febrile neutropenia and an empirical antibiotic therapy with piperacillintazobactam plus amikacin was started. After 3 days of persistent fever, and following the detection of Escherichia coli in the blood, piperacillin-tazobactam was replaced with ertapenem. In the following 24 hours the fever disappeared. However, a new febrile
☆ The study was performed at the Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144, Rome, Italy. ⁎ Corresponding author. Department of Hematology, Azienda Policlinico Umberto I, 00161, Rome, Italy. Tel.: +39-06-857951; fax: +39-06-44241984. E-mail address: [email protected] (C. Girmenia). 0732-8893/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.diagmicrobio.2013.02.005
episode recurred after 6 days, while still under antibacterial therapy. Pulmonary CT scan showed a lung consolidation and serum GM assay was positive. A presumed diagnosis of IA was posed and amphotericin B lipid complex (5 mg/kg/d) was administered to the patient. After 3 days of antifungal treatment, the patient continued to be febrile and serially collected serum samples still showed positive GM assay. In the mean time, the microbiology laboratory identified the presence of L.monocytogenes in multiple blood cultures from samples collected since the first day of recurrent fever (BacTALERT 3D aerobic/anerobic blood cultures system and VITEK 2 Gram-positive microbial identification card were used). Ertapenem and amikacin therapy was replaced with intravenous ampicillin (2 g/4 hours), and within 24 hours the fever disappeared and the patient's clinical condition started to consistently improve. Blood cultures performed on samples collected after starting ampicillin administration confirmed the disappearance of L. monocytogenes and the intensity of GM detection in sera showed a progressive reduction. Both antibacterial and antifungal therapy were administered for further 4 weeks until complete resolution of the pulmonary infiltrate. Although the possibility of an undetected pulmonary Aspergillus infection could not be completely ruled out in the absence of invasive diagnostic exams (for this reason we decided to administer both antibacterial and antifungal therapy until resolution of the pulmonary infection), the microbiologic assessment and clinical findings suggested that a coinfection by L. monocytogenes and Aspergillus spp. was an unlikely event and the pulmonary infiltrate was probably due to the bacterial pathogen. It should be also noted that at the time of serum sample collection, the patient did not receive any antibiotics,
M.C. Petti et al. / Diagnostic Microbiology and Infectious Disease 76 (2013) 250–251
251
Fig. 1. Clinical and microbiological findings of the patient.
such as piperacillin-tazobactam (discontinues several days before) or amoxicillin-clavulanate, which are known to cause a false positive result for GM (Mennink-Kersten et al., 2004a). We therefore hypothesized that the positive GM testing might depend on a crossrecognition of antigens released by L. monocytogenes. To verify this, we explored whether the L. monocytogenes strain isolated from the patient was capable of producing antigens cross-reacting with the Aspergillus GM. Briefly, after growth on Columbia blood agar, a colony of L. monocytogenes was isolated and suspended in saline solution at a 0.5 Mc Farland concentration. After vigorous agitation, the suspension was centrifuged for 5 min at 10,000×g, and serial dilutions of the supernatant were tested with GM assay. Control for the experiment included saline solution alone, supernatants of 0.5 Mc Farland suspension of heterologous bacteria (Staphylococcus aureus and Escherichia coli strains grown on Columbia blood agar) and of another L. monocytogenes strain from our laboratory collection, as well as negative, positive, and standard (1-ng/ml) serum samples, respectively, provided by the assay manufacturer. The L. monocytogenes strain from our patient showed positive indexes in a concentrationdependent manner, starting from 3.7 of the undiluted supernatant to 2.0, 1.2, 0.9 and 0.5 of the 1:2, 1:4, 1:8 and 1:16 dilutions, respectively. The other control L. monocytogenes strain showed positive indexes starting from 3.1 of the undiluted supernatant to 0.7 of the 1:8 dilution. The two heterologous bacteria controls showed a minimal response only with undiluted supernatant 0.8 index for S. aureus and 0.5 for E. coli. To date, no evidence of false-positive results due to bacterial invasive infection has been reported by using the GM assay. However, cross-recognition of heterologous antigens by the GM assay has been reported with Bifidobacterium sp, a Gram-positive bacteria that commonly colonize the gut in neonates and infants (Mennink-Kersten et al., 2004b, 2005). It has been suggested that in these latter cases, the immaturity of the intestinal mucosa might determine the translocation of lipoteichoic acid (LTA), a polymer tethered by a lipid anchor to the bacterial membrane, which, in turn, has been shown to cause a false positive result in serum by GM assay. In fact, it has been found that a LTA molecule of Bifidobacterium bifidum subsp. Pennsylvanicum contained a terminal linear polysaccharide which mimics the epitope recognized by EB-A2, the immunoglobulin M monoclonal antibody representing the detection antibody in the GM Platelia® assay (Mennink-Kersten et al., 2004b, 2005). Considering that all gram positive bacteria harbour a highly variable protective surface structure, composed by thick layers of peptidoglycan interlaced with glycopolymers, including LTA, we can hypothesize that the GM positive detection in sera from our patient might depend on a cross
recognition of a L. monocytogenes LTA, or, possibly another still unrecognized exoantigen, with the EB-A2 monoclonal antibody. This hypothesis is supported by the results of our “in vitro” studies, which showed a significant positive detection of GM in supernatants of both patient and control L. monocytogens strains as well as the progressive reduction of GM antigenemia “in vivo” after starting a specific ampicillin treatment for Listeria infection. Previous studies (Mennink-Kersten et al., 2005) directed at establish the potential for a cross-recognition of GM induced by several bacteria did not report any significant cross recognition induced by L. monocytogenes (a single strain was tested). This apparent discrepancy in the results emerging from our study is intriguing, and might involve structural variants of LTA from L. monocytogenes, as previously demonstrated by several authors (Fischer 1988; Hether and Jackson, 1983; Uchikawa et al., 1986), which may be responsible of generating a variable recognition by the EB-A2 monoclonal antibody. Further “in vitro” studies directed at exploring multiple L. monocytogenes strains, should be performed to finely dissect this issue. References Bonini A, Capatti C, Parmeggiani M, Gugliotta L, Micozzi A, Gentile G, et al. Galactomannan detection in Geotrichum capitatum invasive infections: report of 2 new cases and review of diagnostic options. Diagn Microbiol Infect Dis 2008;62: 450–2. De Pauw B, Walsh TJ, Donnelly JP, Stevens DA, Edwards JE, Calandra T, et al. Revised definitions of invasive fungal disease from the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) Consensus Group. Clin Infect Dis 2008;46:1813–21. Fischer W. Physiology of lipoteichoic acids in bacteria. Adv Microb Physiol 1988;29: 233–302. Hether NW, Jackson LL. Lipoteichoic acid from Listeria monocytogenes. J Bacteriol 1983;156:809–17. Huang YT, Hung CC, Liao CH, Sun HY, Chang SC, Chen YC. Detection of circulating galactomannan in serum samples for diagnosis of Penicillium marneffei infection and cryptococcosis among patients infected with human immunodeficiency virus. J Clin Microbiol 2007;45:2858–62. Mennink-Kersten MA, Donnelly JP, Verweij PE. Detection of circulating galactomannan for the diagnosis and management of invasive aspergillosis. Lancet Infect Dis 2004a;4:349–57. Mennink-Kersten MA, Klont RR, Warris A, Op den Camp HJ, Verweij PE. Bifidobacterium lipoteichoic acid and false ELISA reactivity in aspergillus antigen detection. Lancet 2004b;363:325–7. Mennink-Kersten MA, Ruegebrink D, Klont RR, Warris A, Gavini F, Op den Camp HJ, et al. Bifidobacterial lipoglycan as a new cause for false-positive platelia Aspergillus enzyme-linked immunosorbent assay reactivity. J Clin Microbiol 2005;43:3925–31. Tortorano AM, Esposto MC, Prigitano A, Grancini A, Ossi C, Cavanna C. Cross-reactivity of Fusarium spp. in the aspergillus galactomannan enzyme-linked immunosorbent assay. J Clin Microbiol 2012;50:1051–3. Uchikawa K, Sekikawa I, Azuma I. Structural studies on lipoteichoic acids from four Listeria strains. J Bacteriol 1986;168:115–22.
Contents lists available at SciVerse ScienceDirect
Diagnostic Microbiology and Infectious Disease journal homepage: www.elsevier.com/locate/diagmicrobio
Cross-recognition of aspergillus galactomannan caused by Listeria monocytogenes infection☆ Maria Concetta Petti a, Grazia Prignano b, Andrea Mengarelli a, Antonio Spadea a, Laura Cilli b, Corrado Girmenia c,⁎ a b c
Department of Hematology, Regina Elena National Cancer Institute, Rome, Italy Clinical Pathology and Microbiology Laboratory, San Gallicano Dermatology Institute, Rome, Italy Department of Hematology, Azienda Policlinico Umberto I, Rome, Italy
a r t i c l e
i n f o
Article history: Received 28 December 2012 Received in revised form 11 February 2013 Accepted 12 February 2013 Available online 19 March 2013
a b s t r a c t We report a case of Listeria monocytogenes bacteremia in a leukemic patient having a positive assay for aspergillus galactomannan (GM), although no evidence of aspergillosis was found. Supernatant obtained from L. monocytogenes strain suspension was reactive with GM-assay. L. monocytogenes produces a soluble antigen that is cross-reactive with Aspergillus GM. © 2013 Elsevier Inc. All rights reserved.
Keywords: Listeria monocytogenes Galactomannan Cross-reaction
Aspergillus galactomannan (GM) detection by Platelia® assay has been introduced among the microbiologic criteria for the diagnosis of invasive aspergillosis (IA) (de Pauw et al., 2008). A major problem with the detection of circulating GM is the occurrence of false-positive results, which, in some cases, have been shown to be related to a cross-recognition of non-Aspergillus pathogens such as Fusarium spp, Penicillium species, and Geotrichum capitatum (Bonini et al., 2008; Huang et al., 2007; Mennink-Kersten et al., 2004a; Tortorano et al., 2012). We describe the case of a positive GM assay in a leukemic patient with Listeria monocytogenes bacteremia. A 61-year-old man with an acute myeloid leukemia underwent a salvage treatment with fludarabine, idarubicine and cytosinearabinoside after failure of first induction chemotherapy which had not been complicated by any infection. Oral ciprofloxacin and posaconazole prophylaxis were administered during neutropenia. Clinical and microbiologic assessment during the period following chemotherapy are detailed in Fig. 1. The patient developed a febrile neutropenia and an empirical antibiotic therapy with piperacillintazobactam plus amikacin was started. After 3 days of persistent fever, and following the detection of Escherichia coli in the blood, piperacillin-tazobactam was replaced with ertapenem. In the following 24 hours the fever disappeared. However, a new febrile
☆ The study was performed at the Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144, Rome, Italy. ⁎ Corresponding author. Department of Hematology, Azienda Policlinico Umberto I, 00161, Rome, Italy. Tel.: +39-06-857951; fax: +39-06-44241984. E-mail address: [email protected] (C. Girmenia). 0732-8893/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.diagmicrobio.2013.02.005
episode recurred after 6 days, while still under antibacterial therapy. Pulmonary CT scan showed a lung consolidation and serum GM assay was positive. A presumed diagnosis of IA was posed and amphotericin B lipid complex (5 mg/kg/d) was administered to the patient. After 3 days of antifungal treatment, the patient continued to be febrile and serially collected serum samples still showed positive GM assay. In the mean time, the microbiology laboratory identified the presence of L.monocytogenes in multiple blood cultures from samples collected since the first day of recurrent fever (BacTALERT 3D aerobic/anerobic blood cultures system and VITEK 2 Gram-positive microbial identification card were used). Ertapenem and amikacin therapy was replaced with intravenous ampicillin (2 g/4 hours), and within 24 hours the fever disappeared and the patient's clinical condition started to consistently improve. Blood cultures performed on samples collected after starting ampicillin administration confirmed the disappearance of L. monocytogenes and the intensity of GM detection in sera showed a progressive reduction. Both antibacterial and antifungal therapy were administered for further 4 weeks until complete resolution of the pulmonary infiltrate. Although the possibility of an undetected pulmonary Aspergillus infection could not be completely ruled out in the absence of invasive diagnostic exams (for this reason we decided to administer both antibacterial and antifungal therapy until resolution of the pulmonary infection), the microbiologic assessment and clinical findings suggested that a coinfection by L. monocytogenes and Aspergillus spp. was an unlikely event and the pulmonary infiltrate was probably due to the bacterial pathogen. It should be also noted that at the time of serum sample collection, the patient did not receive any antibiotics,
M.C. Petti et al. / Diagnostic Microbiology and Infectious Disease 76 (2013) 250–251
251
Fig. 1. Clinical and microbiological findings of the patient.
such as piperacillin-tazobactam (discontinues several days before) or amoxicillin-clavulanate, which are known to cause a false positive result for GM (Mennink-Kersten et al., 2004a). We therefore hypothesized that the positive GM testing might depend on a crossrecognition of antigens released by L. monocytogenes. To verify this, we explored whether the L. monocytogenes strain isolated from the patient was capable of producing antigens cross-reacting with the Aspergillus GM. Briefly, after growth on Columbia blood agar, a colony of L. monocytogenes was isolated and suspended in saline solution at a 0.5 Mc Farland concentration. After vigorous agitation, the suspension was centrifuged for 5 min at 10,000×g, and serial dilutions of the supernatant were tested with GM assay. Control for the experiment included saline solution alone, supernatants of 0.5 Mc Farland suspension of heterologous bacteria (Staphylococcus aureus and Escherichia coli strains grown on Columbia blood agar) and of another L. monocytogenes strain from our laboratory collection, as well as negative, positive, and standard (1-ng/ml) serum samples, respectively, provided by the assay manufacturer. The L. monocytogenes strain from our patient showed positive indexes in a concentrationdependent manner, starting from 3.7 of the undiluted supernatant to 2.0, 1.2, 0.9 and 0.5 of the 1:2, 1:4, 1:8 and 1:16 dilutions, respectively. The other control L. monocytogenes strain showed positive indexes starting from 3.1 of the undiluted supernatant to 0.7 of the 1:8 dilution. The two heterologous bacteria controls showed a minimal response only with undiluted supernatant 0.8 index for S. aureus and 0.5 for E. coli. To date, no evidence of false-positive results due to bacterial invasive infection has been reported by using the GM assay. However, cross-recognition of heterologous antigens by the GM assay has been reported with Bifidobacterium sp, a Gram-positive bacteria that commonly colonize the gut in neonates and infants (Mennink-Kersten et al., 2004b, 2005). It has been suggested that in these latter cases, the immaturity of the intestinal mucosa might determine the translocation of lipoteichoic acid (LTA), a polymer tethered by a lipid anchor to the bacterial membrane, which, in turn, has been shown to cause a false positive result in serum by GM assay. In fact, it has been found that a LTA molecule of Bifidobacterium bifidum subsp. Pennsylvanicum contained a terminal linear polysaccharide which mimics the epitope recognized by EB-A2, the immunoglobulin M monoclonal antibody representing the detection antibody in the GM Platelia® assay (Mennink-Kersten et al., 2004b, 2005). Considering that all gram positive bacteria harbour a highly variable protective surface structure, composed by thick layers of peptidoglycan interlaced with glycopolymers, including LTA, we can hypothesize that the GM positive detection in sera from our patient might depend on a cross
recognition of a L. monocytogenes LTA, or, possibly another still unrecognized exoantigen, with the EB-A2 monoclonal antibody. This hypothesis is supported by the results of our “in vitro” studies, which showed a significant positive detection of GM in supernatants of both patient and control L. monocytogens strains as well as the progressive reduction of GM antigenemia “in vivo” after starting a specific ampicillin treatment for Listeria infection. Previous studies (Mennink-Kersten et al., 2005) directed at establish the potential for a cross-recognition of GM induced by several bacteria did not report any significant cross recognition induced by L. monocytogenes (a single strain was tested). This apparent discrepancy in the results emerging from our study is intriguing, and might involve structural variants of LTA from L. monocytogenes, as previously demonstrated by several authors (Fischer 1988; Hether and Jackson, 1983; Uchikawa et al., 1986), which may be responsible of generating a variable recognition by the EB-A2 monoclonal antibody. Further “in vitro” studies directed at exploring multiple L. monocytogenes strains, should be performed to finely dissect this issue. References Bonini A, Capatti C, Parmeggiani M, Gugliotta L, Micozzi A, Gentile G, et al. Galactomannan detection in Geotrichum capitatum invasive infections: report of 2 new cases and review of diagnostic options. Diagn Microbiol Infect Dis 2008;62: 450–2. De Pauw B, Walsh TJ, Donnelly JP, Stevens DA, Edwards JE, Calandra T, et al. Revised definitions of invasive fungal disease from the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) Consensus Group. Clin Infect Dis 2008;46:1813–21. Fischer W. Physiology of lipoteichoic acids in bacteria. Adv Microb Physiol 1988;29: 233–302. Hether NW, Jackson LL. Lipoteichoic acid from Listeria monocytogenes. J Bacteriol 1983;156:809–17. Huang YT, Hung CC, Liao CH, Sun HY, Chang SC, Chen YC. Detection of circulating galactomannan in serum samples for diagnosis of Penicillium marneffei infection and cryptococcosis among patients infected with human immunodeficiency virus. J Clin Microbiol 2007;45:2858–62. Mennink-Kersten MA, Donnelly JP, Verweij PE. Detection of circulating galactomannan for the diagnosis and management of invasive aspergillosis. Lancet Infect Dis 2004a;4:349–57. Mennink-Kersten MA, Klont RR, Warris A, Op den Camp HJ, Verweij PE. Bifidobacterium lipoteichoic acid and false ELISA reactivity in aspergillus antigen detection. Lancet 2004b;363:325–7. Mennink-Kersten MA, Ruegebrink D, Klont RR, Warris A, Gavini F, Op den Camp HJ, et al. Bifidobacterial lipoglycan as a new cause for false-positive platelia Aspergillus enzyme-linked immunosorbent assay reactivity. J Clin Microbiol 2005;43:3925–31. Tortorano AM, Esposto MC, Prigitano A, Grancini A, Ossi C, Cavanna C. Cross-reactivity of Fusarium spp. in the aspergillus galactomannan enzyme-linked immunosorbent assay. J Clin Microbiol 2012;50:1051–3. Uchikawa K, Sekikawa I, Azuma I. Structural studies on lipoteichoic acids from four Listeria strains. J Bacteriol 1986;168:115–22.