First case of bacteraemia due to Acinetobacter schindleri harbouring blaNDM-1 in an immunocompromised patient.

Clinically significant NDM-1-producing Acinetobacter schindleri has not yet been described in the literature. We report the first case of bacteraemia due to an A. schindleri strain harbouring blaNDM-1 recovered from an immunocompromised patient. Our report reinforces the fact that NDM-1 can easily be acquired by Acinetobacter species.

Caracterización fenotípica y genotípica de la resistencia a imipenem en Pseudomonas aeruginosa aisladas en un hospital de Buenos Aires / Phenotypic and genotypic characterization of imipenem-resistant Pseudomonas aeruginosa isolated in Buenos Aires

En el presente estudio, que tuvo por objeto analizar los mecanismos involucrados en la resistencia a carbapenemes, se incluyeron 129 aislamientos de Pseudomonas aeruginosa recuperados durante el año 2006 en el Hospital "Eva Perón" de la Provincia de Buenos Aires. La caracterización fenotípica y genotípica de la resistencia permitió reconocer la presencia de metalo-beta-lactamasas (MBL) en el 14% de esos aislamientos. En todos ellos se identificó la presencia de la enzima IMP-13; sin embargo, algunos aislamientos resultaron sensibles a carbapenemes de acuerdo con los puntos de corte establecidos por el CLSI e incluso con las sugerencias de la Subcomisión de Antimicrobianos de SADEBAC, AAM. El ensayo de detección fenotípica de MBL de sinergia con doble disco resultó útil en este estudio. Sólo aquellos aislamientos productores de IMP-13 que a su vez presentaron alteraciones en las proteínas de membrana externa resultaron completamente resistentes a imipenem. Los aislamientos productores de MBL correspondieron a varios tipos clonales, lo cual sugiere no sólo la diseminación de una cepa resistente, sino también la diseminación horizontal de este mecanismo de resistencia entre clones diferentes.

From 129 P. aeruginosa isolated at a health care centre located in Buenos Aires (Hospital "Eva Perón"), 14% produced IMP-13. Although 18 isolates were metallo-beta-lactamases (MBL) producers, only those isolates that displayed altered outer membrane protein profiles correlated with the resistant category according to CLSI or even Subcomisión de Antimicrobianos, SADEBAC, AAM. Phenotypic screening of metallo-beta-lactamases proved to be appropriate for detecting MBL producing isolates. IMP-13 producing isolates corresponded to at least five different clonal types, which not only suggests the dissemination of the resistant strain but also of the resistant marker.

[Phenotypic and genotypic characterization of imipenem-resistant Pseudomonas aeruginosa isolated in a Buenos Aires hospital]. / Caracterización fenotípica y genotípica de la resistencia a imipenem en Pseudomonas aeruginosa aisladas en un hospital de Buenos Aires.

From 129 P. aeruginosa isolated at a health care centre located in Buenos Aires (Hospital "Eva Perón"), 14% produced IMP-13. Although 18 isolates were metallo-beta-lactamases (MBL) producers, only those isolates that displayed altered outer membrane protein profiles correlated with the resistant category according to CLSI or even Subcomisión de Antimicrobianos, SADEBAC, AAM. Phenotypic screening of metallo-beta-lactamases proved to be appropriate for detecting MBL producing isolates. IMP-13 producing isolates corresponded to at least five different clonal types, which not only suggests the dissemination of the resistant strain but also of the resistant marker.

[Community-acquired methicillin-resistant Staphylococcus aureus infections in a hospital for acute diseases]. / Infecciones adquiridas en la comunidad por Staphylococcus aureus resistente a meticilina en un hospital de agudos.

Community-acquired methicillin-resistant Staphylococcus aureus infections in a hospital for acute diseases. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent pathogens associated with nosocomial infections. However, most recently, MRSA has arisen as an emerging community pathogen, causing serious infections, mainly among young patients. We herein describe 33 cases of infections caused by community-acquired MRSA (C-MRSA), diagnosed between May 2005 and June 2006, at "Eva Perón" Hospital. The isolations were retrospectively studied. Methicillin resistance was confirmed by means of the detection of the mecA gene, and the genes for two virulence factors (Panton-Valentine Leucocidin -PVL- and gamma-haemolysin) as well as the cassette mec type were screened by PCR. All the patients were previously healthy. Four patients under 12, presented bacteremia, one had serious pneumonia, and the three remaining patients had osteoarticular infections; all the patients over 12, had skin and soft tissue infections without systemic damage. The C-MRSA strains harboured cassette mec type IV, and the PVL and gamma-haemolysin genes. They were methicillin-resistant, with no other associated resistances. It is important to consider the presence of these community- acquired strains in order to develop strategies for their correct treatment.

Infecciones adquiridas en la comunidad por Staphylococcus aureus resistente a meticilina en un hospital de agudos / Community-acquired methicillin-resistant Staphylococcus aureus infections in a hospital for acute diseases

Staphylococcus aureus resistente a meticilina (SAMR) es uno de los principales agentes asociados a infecciones intrahospitalarias; sin embargo, en los últimos años ha surgido como un patógeno emergente de la comunidad, causando infecciones graves, principalmente en jóvenes. Se describen 33 casos de infecciones por SAMR de origen comunitario, diagnosticadas entre mayo de 2005 y junio de 2006 en el HIGA "Eva Perón". Se estudiaron retrospectivamente los aislamientos; se confirmó la resistencia a meticilina mediante la detección del gen mecA, se investigó la presencia de genes que codifican dos factores de virulencia (leucocidina de Panton-Valentine -LPV- y g-hemolisina) y el tipo de casete mec mediante PCR. Todos los pacientes se encontraban sanos previamente. Cuatro pacientes menores de 12 años presentaron bacteriemia, uno con neumonía grave y los 3 restantes con infección osteoarticular; todos los pacientes mayores de 12 años presentaron infecciones de piel y partes blandas sin compromiso sistémico. Se constató la presencia de casete mec tipo IV en todos los aislamientos; la resistencia a meticilina no se acompañó de resistencia a otros antimicrobianos; los aislamientos fueron portadores de genes que codifican para LPV y para g-hemolisina. Es importante considerar la presencia de estas cepas de origen comunitario a fin de elaborar estrategias para su correcto tratamiento.

Methicillin- resistant Staphylococcus aureus (MRSA) is one of the most prevalent pathogens associated with nosocomial infections. However, most recently, MRSA has arisen as an emerging community pathogen, causing serious infections, mainly among young patients. We herein describe 33 cases of infections caused by community-acquired MRSA (CMRSA), diagnosed between May 2005 and June 2006, at "Eva Perón" Hospital. The isolations were retrospectively studied. Methicillin resistance was confirmed by means of the detection of the mecA gene, and the genes for two virulence factors (Panton-Valentine Leucocidin -PVL- and g-haemolysin) as well as the cassette mec type were screened by PCR. All the patients were previously healthy. Four patients under 12, presented bacteremia, one had serious pneumonia, and the three remaining patients had osteoarticular infections; all the patients over 12, had skin and soft tissue infections without systemic damage. The C-MRSA strains harboured cassette mec type IV, and the PVL and g-haemolysin genes. They were methicillin-resistant, with no other associated resistances. It is important to consider the presence of these community- acquired strains in order to develop strategies for their correct treatment.

[Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study]. / Sistema automatizado de hemocultivos Bact-Alert: 5 vs 7 dias de incubación. Primer estudio multicéntrico argentino.

Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study. Between January and December 2001, we analyzed 80,141 blood cultures by the Bact-Alert system (14,960 FAN aerobics, 3,855 FAN anaerobic, 11,114 standards aerobics, 11,367 standards anaerobic, 12,054 pediatrics and 26,791 FAN pediatrics bottles) and 44.235 series from 27.615 patients at eight hospitals of Buenos Aires city, one of La Plata city and three of the Buenos Aires province. A total of 13,657 blood cultures yielded a positive result. Only 181 of them had been detected as positive between the 5th and 7th day of incubation and only 26 (0.19%) had clinical significance (Staphylococcus aureus 3; coagulase negative staphylococci 2; Enterococcus faecalis 1; Streptococcus pneumoniae 2; Campylobacter spp 1; Escherichia coli 1; Enterobacter cloacae 1; Enterobacteraerogenes 1; Citrobacter freundii 1; Klebsiella pneumoniae 1; Proteus mirabilis 1; Serratia marcescens 4; yeasts 7, including one strain of Cryptococcus neoformans). Of the total of contaminants, 38% were isolated by the anaerobic standard (65% were Propionibacterium spp and 29% coagulase negative staphylococci), 31.2% by the FAN aerobic (33.3% difphteroids and 28.9% Bacillus spp), 11.8% by the pediatric, 9% by FAN pediatric, 8.33% by aerobic standard and 1.4% by FAN anaerobic bottle. Our results show that the prolonged incubation of blood cultures for more than 5 days using the Bact-Alert system is unnecessary.

Sistema automatizado de hemocultivos Bact-Alert: 5 vs 7 dias de incubación. Primer estudio multicéntrico argentino / [Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study]

Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study. Between January and December 2001, we analyzed 80,141 blood cultures by the Bact-Alert system (14,960 FAN aerobics, 3,855 FAN anaerobic, 11,114 standards aerobics, 11,367 standards anaerobic, 12,054 pediatrics and 26,791 FAN pediatrics bottles) and 44.235 series from 27.615 patients at eight hospitals of Buenos Aires city, one of La Plata city and three of the Buenos Aires province. A total of 13,657 blood cultures yielded a positive result. Only 181 of them had been detected as positive between the 5th and 7th day of incubation and only 26 (0.19

) had clinical significance (Staphylococcus aureus 3; coagulase negative staphylococci 2; Enterococcus faecalis 1; Streptococcus pneumoniae 2; Campylobacter spp 1; Escherichia coli 1; Enterobacter cloacae 1; Enterobacteraerogenes 1; Citrobacter freundii 1; Klebsiella pneumoniae 1; Proteus mirabilis 1; Serratia marcescens 4; yeasts 7, including one strain of Cryptococcus neoformans). Of the total of contaminants, 38

were isolated by the anaerobic standard (65

were Propionibacterium spp and 29

by the FAN aerobic (33.3

difphteroids and 28.9

by the pediatric, 9

by aerobic standard and 1.4

by FAN anaerobic bottle. Our results show that the prolonged incubation of blood cultures for more than 5 days using the Bact-Alert system is unnecessary.

Sistema automatizado de hemocultivos Bact-Alert: 5 vs 7 dias de incubación. Primer estudio multicéntrico argentino. / [Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study]

Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study. Between January and December 2001, we analyzed 80,141 blood cultures by the Bact-Alert system (14,960 FAN aerobics, 3,855 FAN anaerobic, 11,114 standards aerobics, 11,367 standards anaerobic, 12,054 pediatrics and 26,791 FAN pediatrics bottles) and 44.235 series from 27.615 patients at eight hospitals of Buenos Aires city, one of La Plata city and three of the Buenos Aires province. A total of 13,657 blood cultures yielded a positive result. Only 181 of them had been detected as positive between the 5th and 7th day of incubation and only 26 (0.19

) had clinical significance (Staphylococcus aureus 3; coagulase negative staphylococci 2; Enterococcus faecalis 1; Streptococcus pneumoniae 2; Campylobacter spp 1; Escherichia coli 1; Enterobacter cloacae 1; Enterobacteraerogenes 1; Citrobacter freundii 1; Klebsiella pneumoniae 1; Proteus mirabilis 1; Serratia marcescens 4; yeasts 7, including one strain of Cryptococcus neoformans). Of the total of contaminants, 38

were isolated by the anaerobic standard (65

were Propionibacterium spp and 29

coagulase negative staphylococci), 31.2

by the FAN aerobic (33.3

difphteroids and 28.9

Bacillus spp), 11.8

by the pediatric, 9

by FAN pediatric, 8.33

by aerobic standard and 1.4

by FAN anaerobic bottle. Our results show that the prolonged incubation of blood cultures for more than 5 days using the Bact-Alert system is unnecessary.

[Dog bite infections associated with CDC group EF-4a. Report of 2 cases]. / Infecciones por mordedura de perro asociadas a CDC grupo EF-4a. Comunicación de 2 casos.

BACKGROUND: Group EF-4 bacteria make up part of the normal flora of the oral cavity of dogs and cats. Few reports have been published on the incidence of human infections by this group of bacteria and these are associated with animal bite or scratch. Two cases of infections by CDC group EF-4 by dog bite were diagnosed in 1996 by the Bacteriology Laboratory of the authors' hospital. These cases are herein described and the biochemical analysis and profile of sensitivity of this little known group of bacteria evaluated. METHODS: Two clinical cases of infection by CDC group EF-4a by dog bite are described. Identification of the bacteria was performed by conventional biochemical tests and quantitative antibiotic sensitivity to 12 antibiotics was carried out by the seried broth macrodilution method. RESULTS: The two strains isolated corresponded to biovar "a" of group EF-4 being sensitive to: ampicillin, ceftriaxone, aminoglycosides, chloramphenicol, rifamipicin, TMS and ciprofloxacin, intermediate sensitivity to erythromycin and were resistant to cefalotine, oxacillin and vancomycin. With respect to penicillin, one of the strains was sensitive and the other presented intermediate sensitivity. Neither of the strains produced beta lactamase. CONCLUSIONS: Although Pasteurella sp. is usually considered in dog bite wounds, the possible presence of group EF-4 should be taken into account since the sensitivity of both microorganisms against penicillin and cefalotin, which are effective against Pasteurella but less active against group EF-4 bacteria differ.

Hereditary angioedema: therapeutic effect of danazol on C4 and C1 esterase inhibitors.

Hereditary angioedema (HAE) is an inherited deficiency of C1 esterase inhibitor (C1 inh). The two types of genetic C1 inh deficiency are type I, which is quantitative, and type II, which is functional. For the purpose of the present study, four HAE patients were selected. None of them had received any androgenic therapy. The group included three type I and one type II cases. All patients that entered the protocol received danazol, 400 mg/day for 14 days. The complement system was evaluated by monitoring C4, hemolytic complement 50% (CH50), circulating immune complexes (CIC), and antigenic and functional C1 inh during the study. The level of complement factors at the beginning and at the end of this period demonstrated a statistically significant increase in C4 and CH50 and the disappearance of CIC, while C1 inh remained unmodified. These results suggest that the therapeutic effect of danazol may have two mechanisms of action: (1) promotion of C4 synthesis by anabolic effect resulting in an improvement of the complement system with the disappearance of CIC and (2) a minor increase in C1 inh level primarily due to the lack of its consumption.

[Hereditary angioedema. Effect of danazol on C4 and functional C1INH]. / Angioedema hereditario (AEH). Acción del danazol sobre el C4 y C1INH funcional.

Hereditary angioedema (HAE) is an inherited deficiency of the inhibitor of C1 esterase (C1 inh). Two types of genetic C1 inh deficiency have been described, type I: quantitative, and type II: functional. For the purpose of the present study, 4 out of 51 HAE patients were selected. None of them had received any previous androgenic therapy. The group was integrated by two type I and one type II cases. All patients that entered in the protocol received 400 mg/day of danazol over 14 days. The complement system was evaluated by monitoring C4, Hemolytic complement 50% (CH50), Circulating Immune Complexes (CIC), and antigenic and functional C1 INH during the study. The level of the complement factors at the beginning and the end of this period demonstrated a statistically significant increase of C4 and CH50 and the disappearance of CIC, while C1INH remained unmodified. These results suggest that the therapeutic effect of Danazol may have two mechanisms of action: i. promotion of C4 synthesis by anabolic effect resulting in an improvement of the complement system with the disappearance of CIC, and ii, a minor increase of C1 inh level primarily due to the lack of its consumption.