Restricción programada de cefalosporinas de tercera generación en contexto de un brote de bacilos gramnegativos productores de beta-lactamasas tipo AmpC en unidades críticas: una experiencia de la vida real / Third-generation cephalosporins programmed restriction in the context of an outbreak of AmpC beta-lactamase-producing gram-negative bacilli in critical units: a real-life experience

INTRODUCCIÓN: La restricción programada (RP) de antimicrobianos puede disminuir selectivamente la tasa de infecciones por determinados microorganismos. En este sentido, los bacilos gramnegativos productores de beta-lactamasas AmpC (BGN-blaAmpC) son seleccionados por el sobreuso de cefalosporinas de tercera generación (C3G). Estas bacterias, también adquieren genes y co-producen otras beta-lactamasas, como las de Nueva Delhi (BGN-blaNDM). OBJETIVOS: Disminuir la tasa de aislamiento de BGN-blaAmpC y BGN-blaNDM en cultivos de pacientes de la UCI luego de una RP de C3G en el marco de un brote nosocomial por estos microrganismos. MATERIALES Y MÉTODOS: Estudio cuasi-experimental, previo (P1= 12 meses) y posterior (P2= 12 meses) a una RP de C3G en un hospital de adultos, donde, en el contexto de brote mencionado, se aplicaron medidas de control de infecciones generales. El uso de antimicrobianos se expresó como "porcentaje de los días de tratamiento (%DDT)"/100 camas ocupadas al día (100-COD). Se compararon las tasas de aislamiento de BGN-blaAmpC y BGN-blaNDM en hemocultivos (HC), mini-lavados bronquio-alveolares (mB) y urocultivos (UC) en la UCI. RESULTADOS: En P2 el consumo de C3G fue 2,5% DDT/100-COD. Hubo un descenso en los aislamientos de BGN-blaAmpC en HC (RR 0,48 [0,2-0,9] p < 0,02) y mB (RR 0,52 [0,3-0,9] p < 0,02), así como también de BGN-blaNDM en HC (RR 8,1 [1,6-39,4] p < 0,00). Conclusiones: La RP de C3G se asoció con la reducción de los BGN-blaAmpC y BGN-blaNDM en HC, así como de los BGN-blaAmpC mB.

BACKGROUND: Programmed restriction (PR) of antimicrobials can selectively decrease the rate of infections by certain microorganisms. In this sense, AmpC beta-lactamase-producing gram-negative bacilli (GNB-blaAmpC) are selected for the overuse of third generation cephalosporins (3GC). These bacteria also acquire genes and co-produce other β-lactamases, such as New Delhi ones (GNB-blaNDM). AIM: To decrease the isolation rate of GNB- blaAmpC and GNB- blaNDM in cultures from ICU patients after a PR of 3GC. METHODS: Quasi-experimental study, before (P1= 12 months) and after (P2= 12 months) a PR of 3GC in an adults' hospital. The use of antibiotics was expressed as "percentage days of treatment (%DOT)" /100 beds occupied per day (100-BOD). The rates of GNB-blaAmpC and GNB-blaNDM were compared in blood cultures (BC), mini-bronchio alveolar lavages (mB) and urine cultures (UC) in the ICU. RESULTS: In P2, 3GC consumption was 2.5% DOT/100-COD. There was a decrease in GNB-blaAmpC from BC (RR 0.48 [0.2-0.9] p < 0.02) and mB (RR 0.52 [0.3-0.9] p < 0.02), as well as of GNB-blaNDM from BC (RR 8.1 [1.6-39.4] p < 0.00). Conclusions: PR of 3GC was linked to the reduction of GNB-blaAmpC and GNB-blaNDM in BC, as well as GNB-blaAmpC in mB from ICU patients.

Evaluation of a Lyophilized CRISPR-Cas12 Assay for a Sensitive, Specific, and Rapid Detection of SARS-CoV-2.

We evaluated a lyophilized CRISPR-Cas12 assay for SARS-CoV-2 detection (Lyo-CRISPR SARS-CoV-2 kit) based on reverse transcription, isothermal amplification, and CRISPR-Cas12 reaction. From a total of 210 RNA samples extracted from nasopharyngeal swabs using spin columns, the Lyo-CRISPR SARS-CoV-2 kit detected 105/105 (100%; 95% confidence interval (CI): 96.55-100) positive samples and 104/105 (99.05%; 95% CI: 94.81-99.97) negative samples that were previously tested using commercial RT-qPCR. The estimated overall Kappa index was 0.991, reflecting an almost perfect concordance level between the two diagnostic tests. An initial validation test was also performed on 30 nasopharyngeal samples collected in lysis buffer, in which the Lyo-CRISPR SARS-CoV-2 kit detected 20/21 (95.24%; 95% CI: 76.18-99.88) positive samples and 9/9 (100%; 95% CI: 66.37-100) negative samples. The estimated Kappa index was 0.923, indicating a strong concordance between the test procedures. The Lyo-CRISPR SARS-CoV-2 kit was suitable for detecting a wide range of RT-qPCR-positive samples (cycle threshold range: 11.45-36.90) and dilutions of heat-inactivated virus (range: 2.5-100 copies/µL); no cross-reaction was observed with the other respiratory pathogens tested. We demonstrated that the performance of the Lyo-CRISPR SARS-CoV-2 kit was similar to that of commercial RT-qPCR, as the former was highly sensitive and specific, timesaving (1.5 h), inexpensive, and did not require sophisticated equipment. The use of this kit would reduce the time taken for diagnosis and facilitate molecular diagnosis in low-resource laboratories.

[Third-generation cephalosporins programmed restriction in the context of an outbreak of AmpC ß-lactamase-producing gram-negative bacilli in critical units: a real-life experience]. / Restricción programada de cefalosporinas de tercera generación en contexto de un brote de bacilos gramnegativos productores de ß-lactamasas tipo AmpC en unidades críticas: una experiencia de la vida real.

BACKGROUND: Programmed restriction (PR) of antimicrobials can selectively decrease the rate of infections by certain microorganisms. In this sense, AmpC ß-lactamase-producing gram-negative bacilli (GNB-blaAmpC) are selected for the overuse of third generation cephalosporins (3GC). These bacteria also acquire genes and co-produce other ß-lactamases, such as New Delhi ones (GNB-blaNDM). AIM: To decrease the isolation rate of GNB- blaAmpC and GNB- blaNDM in cultures from ICU patients after a PR of 3GC. METHODS: Quasi-experimental study, before (P1= 12 months) and after (P2= 12 months) a PR of 3GC in an adults' hospital. The use of antibiotics was expressed as "percentage days of treatment (%DOT)" /100 beds occupied per day (100-BOD). The rates of GNB-blaAmpC and GNB-blaNDM were compared in blood cultures (BC), mini-bronchio alveolar lavages (mB) and urine cultures (UC) in the ICU. RESULTS: In P2, 3GC consumption was 2.5% DOT/100-COD. There was a decrease in GNB-blaAmpC from BC (RR 0.48 [0.2-0.9] p < 0.02) and mB (RR 0.52 [0.3-0.9] p < 0.02), as well as of GNB-blaNDM from BC (RR 8.1 [1.6-39.4] p < 0.00). CONCLUSIONS: PR of 3GC was linked to the reduction of GNB-blaAmpC and GNB-blaNDM in BC, as well as GNB-blaAmpC in mB from ICU patients.

Vigilancia y prevención de gripe A H1N1: estableicmiento del perfil clínico epidemiológico de la morbi-mortalidad en la provincia de Buenos Aires / Surveillance and prevention of H1N1 influenza: stermination of the clinical and epidemiologic profile of morbi-mortality in Buenos Aires province

INTRODUCCION: El virus de Influenza A es un patógeno viral de gran impacto clínico que causa infecciones respiratorias agudas. En 2009 la OMS declaró una pandemia por la emergencia de un nuevo subtipo H1N1 de origen porcino.OBJETIVOS: Describir las características de la infección por Influenza A H1N1 en la Provincia de Buenos Aires a partir de la pandemia de 2009.METODOS: Se realizó un estudio retrospectivo de los datos ingresados al Sistema de Vigilancia Laboratorial (SIVILA) de la Provincia de Buenos Aires y de muestras de aspirados nasofaríngeos en 3 centros de diagnóstico desde mayo de 2009 hasta abril de 2010. Se utilizó RT-PCR y RT-PCR en tiempo real para el diagnóstico.RESULTADOS: Durante 2009 en la provincia se notificaron 2.316 casos de Influenza A H1N1 al SIVILA. La incidencia más baja se observó en mayores de 65 años, en tanto que la mayor fue en pacientes ambulatorios de entre 5 y 9 años y en pacientes internados menores a 4 años. Entre los pacientes fallecidos se observó mayor incidencia en menores a 4 años y 2 picos en pacientes jóvenes (20-24 y 40-44 años). La tasa de mortalidad fue de 2,36/100.000 habitantes y la de letalidad de 7,85%. En 2010 los 3 centros participantes procesaron 1.000 muestras. Se detectó ARN de virus Influenza A en 25 muestras y una fue diagnosticada por RT-PCR como del subtipo pandémico H1N1.CONCLUSIONES: La mayor incidencia de casos observada en pacientes fallecidos, tanto en jóvenes como en menores de 4 años, coincide con lo descrito en pandemias anteriores. Se detectó solamente un caso de H1N1 al año siguiente de la declaración de la pandemia.

INTRODUCTION: The influenza A virus is highly pathogenic and causes acute respiratory infections. In 2009 the World Health Organization declared a pandemic due to an emergent new variant of the influenza virus, the strain H1N1 from porcine origin.OBJECTIVE: To describe the profile of H1N1 infection in Buenos Aires Province since 2009 pandemic.METHODS: A retrospective study was conducted with data collected from the National Laboratory Survey System (SIVILA) of Buenos Aires Province. Samples of nasopharyngeal aspirates were used, obtained between May 2009 and April 2010 from three diagnostic reference centers. RT-PCR and Real Time RT-PCR were used for diagnostic purposes.RESULTS: During 2009, 2.316 cases of H1N1 influenza were reported to SIVILA. The lowest incidence was observed in patients of 65 years or older. On the other hand, the highest incidence was detected among non-hospitalized children aged 5 to 9 years and hospitalized children under 4 years old. Among dead patients, the highest incidence was observed in children under 4 years old and in young people aged 40-40 and 20-24 years. Mortality rate was 2.36/100.000 and lethality was 7.85%. In 2010, the three diagnostic centers screened 1.000 samples. 25 samples were positive for influenza A virus, and only one sample tested positive for H1N1 virus subtype by RT-PCR analysis.CONCLUSIONS: The highest incidence of cases observed in dead patients, both in young people and in children under 4 years old, was compatible with the data of previous influenza pandemics. Onle one case of H1N1 infection was detected one year after the pandemic declaration.

Vigilancia y prevención de gripe A H1N1: estableicmiento del perfil clínico epidemiológico de la morbi-mortalidad en la provincia de Buenos Aires / Surveillance and prevention of H1N1 influenza: stermination of the clinical and epidemiologic profile of morbi-mortality in Buenos Aires province

INTRODUCCION: El virus de Influenza A es un patógeno viral de gran impacto clínico que causa infecciones respiratorias agudas. En 2009 la OMS declaró una pandemia por la emergencia de un nuevo subtipo H1N1 de origen porcino.OBJETIVOS: Describir las características de la infección por Influenza A H1N1 en la Provincia de Buenos Aires a partir de la pandemia de 2009.METODOS: Se realizó un estudio retrospectivo de los datos ingresados al Sistema de Vigilancia Laboratorial (SIVILA) de la Provincia de Buenos Aires y de muestras de aspirados nasofaríngeos en 3 centros de diagnóstico desde mayo de 2009 hasta abril de 2010. Se utilizó RT-PCR y RT-PCR en tiempo real para el diagnóstico.RESULTADOS: Durante 2009 en la provincia se notificaron 2.316 casos de Influenza A H1N1 al SIVILA. La incidencia más baja se observó en mayores de 65 años, en tanto que la mayor fue en pacientes ambulatorios de entre 5 y 9 años y en pacientes internados menores a 4 años. Entre los pacientes fallecidos se observó mayor incidencia en menores a 4 años y 2 picos en pacientes jóvenes (20-24 y 40-44 años). La tasa de mortalidad fue de 2,36/100.000 habitantes y la de letalidad de 7,85%. En 2010 los 3 centros participantes procesaron 1.000 muestras. Se detectó ARN de virus Influenza A en 25 muestras y una fue diagnosticada por RT-PCR como del subtipo pandémico H1N1.CONCLUSIONES: La mayor incidencia de casos observada en pacientes fallecidos, tanto en jóvenes como en menores de 4 años, coincide con lo descrito en pandemias anteriores. Se detectó solamente un caso de H1N1 al año siguiente de la declaración de la pandemia.

INTRODUCTION: The influenza A virus is highly pathogenic and causes acute respiratory infections. In 2009 the World Health Organization declared a pandemic due to an emergent new variant of the influenza virus, the strain H1N1 from porcine origin.OBJECTIVE: To describe the profile of H1N1 infection in Buenos Aires Province since 2009 pandemic.METHODS: A retrospective study was conducted with data collected from the National Laboratory Survey System (SIVILA) of Buenos Aires Province. Samples of nasopharyngeal aspirates were used, obtained between May 2009 and April 2010 from three diagnostic reference centers. RT-PCR and Real Time RT-PCR were used for diagnostic purposes.RESULTS: During 2009, 2.316 cases of H1N1 influenza were reported to SIVILA. The lowest incidence was observed in patients of 65 years or older. On the other hand, the highest incidence was detected among non-hospitalized children aged 5 to 9 years and hospitalized children under 4 years old. Among dead patients, the highest incidence was observed in children under 4 years old and in young people aged 40-40 and 20-24 years. Mortality rate was 2.36/100.000 and lethality was 7.85%. In 2010, the three diagnostic centers screened 1.000 samples. 25 samples were positive for influenza A virus, and only one sample tested positive for H1N1 virus subtype by RT-PCR analysis.CONCLUSIONS: The highest incidence of cases observed in dead patients, both in young people and in children under 4 years old, was compatible with the data of previous influenza pandemics. Onle one case of H1N1 infection was detected one year after the pandemic declaration.