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Emergence of OXA-72-producing Acinetobacter pittii clinical isolates
International Journal of Antimicrobial Agents 43 (2014) 195–200
Contents lists available at ScienceDirect
International Journal of Antimicrobial Agents journal homepage: http://www.elsevier.com/locate/ijantimicag
Letters to the Editor Emergence of OXA-72-producing Acinetobacter pittii clinical isolates Sir, The genus Acinetobacter comprises 47 characterised genomic species, among which species belonging to the Acinetobacter calcoaceticus–Acinetobacter baumannii complex are the most clinically relevant. Within this complex, A. baumannii, Acinetobacter nosocomialis (formerly genomic species 13TU) and Acinetobacter pittii (formerly genomic species 3) are frequently associated with hospital-acquired infections [1]. Carbapenem resistance is being increasingly reported in Acinetobacter spp. isolates and this resistance trait is often related to the production of acquired carbapenem-hydrolysing class D -lactamases (CHDLs) that are disseminating worldwide [2]. Five groups of acquired CHDLs have been identified to date in A. baumannii, namely OXA-23, OXA24/-40, OXA-58, OXA-143 and OXA-235 [2]. OXA-72 is a point mutant of OXA-40 that was first described in carbapenem-resistant A. baumannii clinical isolates in China [2]. It was then reported in Colombia from a clinical isolate (A. pittii 2688), which has been used here as a reference strain [3]. This study was initiated by the isolation of three imipenemnon-susceptible Acinetobacter spp. isolates recovered in three hospitals in France in 2011–2013. Isolate RA1 was from the sputum of a patient hospitalised in November 2011, isolate RA2 was from pus of an 84-year-old patient in December 2011, and isolate RA3 was recovered after rectal screening of a 56-year-old patient in May 2013. These isolates were resistant to penicillins and penicillin–inhibitor combinations and were of intermediate susceptibility to carbapenems according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints (http://www.eucast.org/clinical breakpoints/). By contrast, they remained susceptible to ceftazidime and cefepime as well as to amikacin, rifampicin, colistin, fluoroquinolones, tetracycline and tigecycline according to the EUCAST guidelines. The isolates were identified using the API32GN system (bioMérieux, Marcy l’Étoile, France), partial sequencing of their 16S rDNA genes and matrix-assisted laser desorption/ionisation time-of-flight mass (MALDI-TOF) analysis. Identification results showed that the three Acinetobacter spp. strains belonged to the A. pittii species. Since the resistance phenotype to -lactams suggested the production of a CHDL, corresponding genes were searched by PCR as described previously [2]. Interestingly, PCR followed by sequencing analysis identified the blaOXA-72 gene in the three isolates. To determine the genetic location of the blaOXA-72 gene, transfer of the ticarcillin resistance marker into A. baumannii BM4547 was attempted by liquid mating-out assays at 37 ◦ C and by electrotransformation of a plasmid DNA suspension extracted from the three clinical isolates and the reference strain (A. pittii 2688). Conjugation remained unsuccessful; nevertheless, transformants were obtained for the three clinical isolates and the reference strain, revealing
0924-8579/$ – see front matter © 2013 Published by Elsevier B.V.
Fig. 1. Results of DiversiLab (bioMérieux, La Balme-les-Grottes, France) analysis. The horizontal similarity line showed the cut-off to separate different clones.
that blaOXA-72 was plasmid-located in all isolates. Plasmid analysis using the A. baumannii PCR-based replicon typing (AB-PBRT) scheme revealed that all French isolates possessed a plasmid of ca. 20 kb in size belonging to the GR12 family plasmid, as defined previously [4], whereas the Colombian isolate was negative for this PCR. Shotgun DNA cloning was then performed to identify the genetic structure surrounding the blaOXA-72 gene. It revealed very similar structures to those identified on the GR12 plasmid-type and blaOXA-72 -positive plasmid pMMD identified in a clinical isolate of A. baumannii from Spain [5]. Altogether, these data indicated that these three plasmids, although originating from different strains, were likely the same. Genotypic comparison was performed by DiversiLab following the manufacturer’s instructions (bioMérieux, La Balme-les-Grottes, France). The clinical isolate of OXA-72-producing A. pittii 2688 from Colombia was used as a reference strain for comparison [3]. Genotyping analysis showed that the four isolates corresponded to three distinct clones (A–C) (Fig. 1), with the Colombian isolate being distantly related to the French isolates. Two isolates, namely RA2 and RA3, were closely related. These two isolates have been recovered, respectively, in northern and southern suburb hospitals of Paris in 2011 and 2013. The remaining isolate recovered in another city in France was not related to the others. This study constitutes the very first report of OXA-72-producing A. pittii in Europe following the initial identification of an OXA-72producing A. pittii in Colombia. The fact that the same clone has been recovered in two different hospital settings 2 years apart likely indicated that this clone might be more widespread than expected. The difficulties in identifying A. pittii species might underestimate their clinical relevance, in accordance with a series of recent studies showing that non-baumannii Acinetobacter spp. were more clinically significant than expected. Funding: This work was partially funded by a grant from INSERM (UMR914), by the Université Paris-Sud (Paris, France) and by grants from the European Community [R-GNOSIS, FP7/HEALTH-F3-2011282512 and MAGIC-BULLET, FP7/HEALTH-F3-2001-278232]. Competing interests: None declared. Ethical approval: Not required.
196
Letters to the Editor / International Journal of Antimicrobial Agents 43 (2014) 195–200
References [1] Nemec A, Krizova L, Maixnerova M, van der Reijden TJ, Deschaght P, Passet V, et al. Genotypic and phenotypic characterization of the Acinetobacter calcoaceticus–Acinetobacter baumannii complex with the proposal of Acinetobacter pittii sp. nov. (formerly Acinetobacter genomic species 3) and Acinetobacter nosocomialis sp. nov. (formerly Acinetobacter genomic species 13TU). Res Microbiol 2011;162:393–404. [2] Bonnin RA, Nordmann P, Poirel L. Screening and deciantibiotic resistance phering in Acinetobacter baumannii: a state of the art. Expert Rev Anti Infect Ther 2013;11:571– 83. [3] Montealegre MC, Maya JJ, Correa A, Espinal P, Mojica MF, Ruiz SJ, et al. First identification of OXA-72 carbapenemase from Acinetobacter pittii in Colombia. Antimicrob Agents Chemother 2012;56:3996–8. [4] Bertini A, Poirel L, Mugnier PD, Villa L, Nordmann P, Carattoli A. Characterization and PCR-based replicon typing of resistance plasmids in Acinetobacter baumannii. Antimicrob Agents Chemother 2010;54: 4168–77. [5] Grosso F, Quinteira S, Poirel L, Novais Â, Peixe L. Role of common blaOXA-24/OXA-40 -carrying platforms and plasmids in the spread of OXA-24/OXA40 among Acinetobacter species clinical isolates. Antimicrob Agents Chemother 2012;56:3969–72.
Rémy A. Bonnin a Fernando Docobo-Pérez a Laurent Poirel a,b,∗ Maria-Virginia Villegas c Patrice Nordmann a,b a INSERM U914 ‘Emerging Resistance to Antibiotics’, K.-Bicêtre, France b Medical and Molecular Microbiology Unit, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland c International Center for Medical Research and Training, CIDEIM, Cali, Colombia ∗ Corresponding
author. Present address: Medical and Molecular Microbiology Unit, Department of Medicine, Faculty of Science, University of Fribourg, 3 rue Albert Gockel, CH-1700 Fribourg, Switzerland. Tel.: +41 26 300 9580. E-mail address: [email protected] (L. Poirel) 7 October 2013
http://dx.doi.org/10.1016/j.ijantimicag.2013.10.005
International gatherings and potential for global dissemination of São Paulo metallo--lactamase (SPM) from Brazil Keywords: blaSPM Carbapenemase Pseudomonas aeruginosa Antibiotic resistance Resistance gene
Sir, Brazil will soon host two of the world’s biggest sporting events, ‘2014 FIFA World Cup Brazil’ (http://www.fifa.com/ worldcup/index.html) and ‘Olympic Games Rio de Janeiro (http:// www.olympic.org/rio-2016-summer-olympics). These events are an opportunity for starting the global spread of São Paulo metallo-lactamase (SPM) from Brazil. SPM-1 is a -lactamase with great clinical and epidemiological importance in Brazil [1]. This enzyme is an acquired metallocarbapenemase that confers resistance to all -lactam antibiotics (including carbapenems, cephalosporins and cephamycins), except monobactams. The blaSPM-1 gene is associated with insertion sequence ISCR4, which is a member of the ISCR family and can mobilise flanking DNA segments [2].
SPM-1 was first reported in 2002 in Pseudomonas aeruginosa isolated in Brazil, but SPM-producing P. aeruginosa have now become disseminated to all Brazilian regions; the gene has not (yet) spread to other bacterial species or genera. Even 11 years after their initial description, to date only one case has been reported outside Brazil, in a Swiss patient who had previous healthcare contact in north-east Brazil [2]. There is no obvious explanation for the continuing restricted geography of SPM-1, which contrasts markedly with the global spread observed for other acquired metallo-carbapenemases belonging to the IMP, VIM and NDM families. SPM-producing P. aeruginosa isolates are genetically related and the main clone belongs to sequence type 277 (ST277) [3]. Little is known about the virulence potential associated with SPM-producing P. aeruginosa clones, but the species shows important pathogenic mechanisms involved, for instance, in exoenzyme production and biofilm formation, aggravating diseases and providing great adaptation to persist in hospitals. Importantly, SPM-producing P. aeruginosa frequently display resistance to non-lactams, expressing multiresistance. Therefore, treatment of infections necessitates using antibiotics of last choice such as polymyxins, and infections are associated with increased morbidity and mortality [1]. As the numbers of infections and colonisations by SPMproducers increase, so too does the possibility that blaSPM-1 will ‘escape’ to recombine with a broader range of mobile genetic elements and with potential to spread beyond P. aeruginosa to other Gram-negative bacteria. There is concern that the gene might become established on successful plasmids [4] or associated with high-risk clones [3], and this could aid the international dissemination of blaSPM-1 . Increased globalisation also presents opportunities for the dissemination of infectious diseases and micro-organisms. It is known that international gatherings and international travellers are very involved in the dissemination of micro-organisms and genetic resistance determinants from endemic areas [5,6]. Athletes and spectators from around the world will come to Brazil for the FIFA World Cup in 2014 and the Olympic Games in 2016 and will stay ca. 30 days before returning to their home countries. Some of these people will require hospitalisation for medical care, with the possibility of becoming colonised by acquiring healthcare-associated infections caused by antibiotic-resistant bacteria, such as SPMproducing P. aeruginosa. Infection prevention and control teams, clinicians and microbiology laboratories should be alert to carbapenem- and ceftazidimeresistant bacteria, mainly P. aeruginosa, isolated from people returning from Brazil, and should seek metallo-carbapenemase production in such isolates. We call attention to the opportunity that forthcoming major sporting events offer for the blaSPM-1 gene to travel worldwide and thereafter to become yet another globally disseminated antibiotic resistance and public health problem. Funding: Research grant 2012/14740-3, São Paulo Research Foundation (FAPESP) . L.N. Andrade was supported by postdoctoral fellowship, grant 2011/08892-2, São Paulo Research Foundation (FAPESP). This letter was based on observations and reflections about antibiotic-resistant bacteria during studies supported by the funding agencies. Competing interests: None declared. Ethical approval: Not required.
References [1] Rossi F. The challenges of antimicrobial resistance in Brazil. Clin Infect Dis 2011;52:1138–43.
Contents lists available at ScienceDirect
International Journal of Antimicrobial Agents journal homepage: http://www.elsevier.com/locate/ijantimicag
Letters to the Editor Emergence of OXA-72-producing Acinetobacter pittii clinical isolates Sir, The genus Acinetobacter comprises 47 characterised genomic species, among which species belonging to the Acinetobacter calcoaceticus–Acinetobacter baumannii complex are the most clinically relevant. Within this complex, A. baumannii, Acinetobacter nosocomialis (formerly genomic species 13TU) and Acinetobacter pittii (formerly genomic species 3) are frequently associated with hospital-acquired infections [1]. Carbapenem resistance is being increasingly reported in Acinetobacter spp. isolates and this resistance trait is often related to the production of acquired carbapenem-hydrolysing class D -lactamases (CHDLs) that are disseminating worldwide [2]. Five groups of acquired CHDLs have been identified to date in A. baumannii, namely OXA-23, OXA24/-40, OXA-58, OXA-143 and OXA-235 [2]. OXA-72 is a point mutant of OXA-40 that was first described in carbapenem-resistant A. baumannii clinical isolates in China [2]. It was then reported in Colombia from a clinical isolate (A. pittii 2688), which has been used here as a reference strain [3]. This study was initiated by the isolation of three imipenemnon-susceptible Acinetobacter spp. isolates recovered in three hospitals in France in 2011–2013. Isolate RA1 was from the sputum of a patient hospitalised in November 2011, isolate RA2 was from pus of an 84-year-old patient in December 2011, and isolate RA3 was recovered after rectal screening of a 56-year-old patient in May 2013. These isolates were resistant to penicillins and penicillin–inhibitor combinations and were of intermediate susceptibility to carbapenems according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints (http://www.eucast.org/clinical breakpoints/). By contrast, they remained susceptible to ceftazidime and cefepime as well as to amikacin, rifampicin, colistin, fluoroquinolones, tetracycline and tigecycline according to the EUCAST guidelines. The isolates were identified using the API32GN system (bioMérieux, Marcy l’Étoile, France), partial sequencing of their 16S rDNA genes and matrix-assisted laser desorption/ionisation time-of-flight mass (MALDI-TOF) analysis. Identification results showed that the three Acinetobacter spp. strains belonged to the A. pittii species. Since the resistance phenotype to -lactams suggested the production of a CHDL, corresponding genes were searched by PCR as described previously [2]. Interestingly, PCR followed by sequencing analysis identified the blaOXA-72 gene in the three isolates. To determine the genetic location of the blaOXA-72 gene, transfer of the ticarcillin resistance marker into A. baumannii BM4547 was attempted by liquid mating-out assays at 37 ◦ C and by electrotransformation of a plasmid DNA suspension extracted from the three clinical isolates and the reference strain (A. pittii 2688). Conjugation remained unsuccessful; nevertheless, transformants were obtained for the three clinical isolates and the reference strain, revealing
0924-8579/$ – see front matter © 2013 Published by Elsevier B.V.
Fig. 1. Results of DiversiLab (bioMérieux, La Balme-les-Grottes, France) analysis. The horizontal similarity line showed the cut-off to separate different clones.
that blaOXA-72 was plasmid-located in all isolates. Plasmid analysis using the A. baumannii PCR-based replicon typing (AB-PBRT) scheme revealed that all French isolates possessed a plasmid of ca. 20 kb in size belonging to the GR12 family plasmid, as defined previously [4], whereas the Colombian isolate was negative for this PCR. Shotgun DNA cloning was then performed to identify the genetic structure surrounding the blaOXA-72 gene. It revealed very similar structures to those identified on the GR12 plasmid-type and blaOXA-72 -positive plasmid pMMD identified in a clinical isolate of A. baumannii from Spain [5]. Altogether, these data indicated that these three plasmids, although originating from different strains, were likely the same. Genotypic comparison was performed by DiversiLab following the manufacturer’s instructions (bioMérieux, La Balme-les-Grottes, France). The clinical isolate of OXA-72-producing A. pittii 2688 from Colombia was used as a reference strain for comparison [3]. Genotyping analysis showed that the four isolates corresponded to three distinct clones (A–C) (Fig. 1), with the Colombian isolate being distantly related to the French isolates. Two isolates, namely RA2 and RA3, were closely related. These two isolates have been recovered, respectively, in northern and southern suburb hospitals of Paris in 2011 and 2013. The remaining isolate recovered in another city in France was not related to the others. This study constitutes the very first report of OXA-72-producing A. pittii in Europe following the initial identification of an OXA-72producing A. pittii in Colombia. The fact that the same clone has been recovered in two different hospital settings 2 years apart likely indicated that this clone might be more widespread than expected. The difficulties in identifying A. pittii species might underestimate their clinical relevance, in accordance with a series of recent studies showing that non-baumannii Acinetobacter spp. were more clinically significant than expected. Funding: This work was partially funded by a grant from INSERM (UMR914), by the Université Paris-Sud (Paris, France) and by grants from the European Community [R-GNOSIS, FP7/HEALTH-F3-2011282512 and MAGIC-BULLET, FP7/HEALTH-F3-2001-278232]. Competing interests: None declared. Ethical approval: Not required.
196
Letters to the Editor / International Journal of Antimicrobial Agents 43 (2014) 195–200
References [1] Nemec A, Krizova L, Maixnerova M, van der Reijden TJ, Deschaght P, Passet V, et al. Genotypic and phenotypic characterization of the Acinetobacter calcoaceticus–Acinetobacter baumannii complex with the proposal of Acinetobacter pittii sp. nov. (formerly Acinetobacter genomic species 3) and Acinetobacter nosocomialis sp. nov. (formerly Acinetobacter genomic species 13TU). Res Microbiol 2011;162:393–404. [2] Bonnin RA, Nordmann P, Poirel L. Screening and deciantibiotic resistance phering in Acinetobacter baumannii: a state of the art. Expert Rev Anti Infect Ther 2013;11:571– 83. [3] Montealegre MC, Maya JJ, Correa A, Espinal P, Mojica MF, Ruiz SJ, et al. First identification of OXA-72 carbapenemase from Acinetobacter pittii in Colombia. Antimicrob Agents Chemother 2012;56:3996–8. [4] Bertini A, Poirel L, Mugnier PD, Villa L, Nordmann P, Carattoli A. Characterization and PCR-based replicon typing of resistance plasmids in Acinetobacter baumannii. Antimicrob Agents Chemother 2010;54: 4168–77. [5] Grosso F, Quinteira S, Poirel L, Novais Â, Peixe L. Role of common blaOXA-24/OXA-40 -carrying platforms and plasmids in the spread of OXA-24/OXA40 among Acinetobacter species clinical isolates. Antimicrob Agents Chemother 2012;56:3969–72.
Rémy A. Bonnin a Fernando Docobo-Pérez a Laurent Poirel a,b,∗ Maria-Virginia Villegas c Patrice Nordmann a,b a INSERM U914 ‘Emerging Resistance to Antibiotics’, K.-Bicêtre, France b Medical and Molecular Microbiology Unit, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland c International Center for Medical Research and Training, CIDEIM, Cali, Colombia ∗ Corresponding
author. Present address: Medical and Molecular Microbiology Unit, Department of Medicine, Faculty of Science, University of Fribourg, 3 rue Albert Gockel, CH-1700 Fribourg, Switzerland. Tel.: +41 26 300 9580. E-mail address: [email protected] (L. Poirel) 7 October 2013
http://dx.doi.org/10.1016/j.ijantimicag.2013.10.005
International gatherings and potential for global dissemination of São Paulo metallo--lactamase (SPM) from Brazil Keywords: blaSPM Carbapenemase Pseudomonas aeruginosa Antibiotic resistance Resistance gene
Sir, Brazil will soon host two of the world’s biggest sporting events, ‘2014 FIFA World Cup Brazil’ (http://www.fifa.com/ worldcup/index.html) and ‘Olympic Games Rio de Janeiro (http:// www.olympic.org/rio-2016-summer-olympics). These events are an opportunity for starting the global spread of São Paulo metallo-lactamase (SPM) from Brazil. SPM-1 is a -lactamase with great clinical and epidemiological importance in Brazil [1]. This enzyme is an acquired metallocarbapenemase that confers resistance to all -lactam antibiotics (including carbapenems, cephalosporins and cephamycins), except monobactams. The blaSPM-1 gene is associated with insertion sequence ISCR4, which is a member of the ISCR family and can mobilise flanking DNA segments [2].
SPM-1 was first reported in 2002 in Pseudomonas aeruginosa isolated in Brazil, but SPM-producing P. aeruginosa have now become disseminated to all Brazilian regions; the gene has not (yet) spread to other bacterial species or genera. Even 11 years after their initial description, to date only one case has been reported outside Brazil, in a Swiss patient who had previous healthcare contact in north-east Brazil [2]. There is no obvious explanation for the continuing restricted geography of SPM-1, which contrasts markedly with the global spread observed for other acquired metallo-carbapenemases belonging to the IMP, VIM and NDM families. SPM-producing P. aeruginosa isolates are genetically related and the main clone belongs to sequence type 277 (ST277) [3]. Little is known about the virulence potential associated with SPM-producing P. aeruginosa clones, but the species shows important pathogenic mechanisms involved, for instance, in exoenzyme production and biofilm formation, aggravating diseases and providing great adaptation to persist in hospitals. Importantly, SPM-producing P. aeruginosa frequently display resistance to non-lactams, expressing multiresistance. Therefore, treatment of infections necessitates using antibiotics of last choice such as polymyxins, and infections are associated with increased morbidity and mortality [1]. As the numbers of infections and colonisations by SPMproducers increase, so too does the possibility that blaSPM-1 will ‘escape’ to recombine with a broader range of mobile genetic elements and with potential to spread beyond P. aeruginosa to other Gram-negative bacteria. There is concern that the gene might become established on successful plasmids [4] or associated with high-risk clones [3], and this could aid the international dissemination of blaSPM-1 . Increased globalisation also presents opportunities for the dissemination of infectious diseases and micro-organisms. It is known that international gatherings and international travellers are very involved in the dissemination of micro-organisms and genetic resistance determinants from endemic areas [5,6]. Athletes and spectators from around the world will come to Brazil for the FIFA World Cup in 2014 and the Olympic Games in 2016 and will stay ca. 30 days before returning to their home countries. Some of these people will require hospitalisation for medical care, with the possibility of becoming colonised by acquiring healthcare-associated infections caused by antibiotic-resistant bacteria, such as SPMproducing P. aeruginosa. Infection prevention and control teams, clinicians and microbiology laboratories should be alert to carbapenem- and ceftazidimeresistant bacteria, mainly P. aeruginosa, isolated from people returning from Brazil, and should seek metallo-carbapenemase production in such isolates. We call attention to the opportunity that forthcoming major sporting events offer for the blaSPM-1 gene to travel worldwide and thereafter to become yet another globally disseminated antibiotic resistance and public health problem. Funding: Research grant 2012/14740-3, São Paulo Research Foundation (FAPESP) . L.N. Andrade was supported by postdoctoral fellowship, grant 2011/08892-2, São Paulo Research Foundation (FAPESP). This letter was based on observations and reflections about antibiotic-resistant bacteria during studies supported by the funding agencies. Competing interests: None declared. Ethical approval: Not required.
References [1] Rossi F. The challenges of antimicrobial resistance in Brazil. Clin Infect Dis 2011;52:1138–43.