Oral administration of recombinant Neisseria meningitidis PorA genetically fused to H. pylori HpaA antigen increases antibody levels in mouse serum, suggesting that PorA behaves as a putative adjuvant.

The Neisseria meningitidis outer membrane protein PorA from a Chilean strain was purified as a recombinant protein. PorA mixed with AbISCO induced bactericidal antibodies against N. meningitidis in mice. When PorA was fused to the Helicobacter pylori HpaA antigen gene, the specific response against H. pylori protein increased. Splenocytes from PorA-immunized mice were stimulated with PorA, and an increase in the secretion of IL-4 was observed compared with that of IFN-γ. Moreover, in an immunoglobulin sub-typing analysis, a substantially higher IgG1 level was found compared with IgG2a levels, suggesting a Th2-type immune response. This study revealed a peculiar behavior of the purified recombinant PorA protein per se in the absence of AbISCO as an adjuvant. Therefore, the resistance of PorA to proteolytic enzymes, such as those in the gastrointestinal tract, was analyzed, because this is an important feature for an oral protein adjuvant. Finally, we found that PorA fused to the H. pylori HpaA antigen, when expressed in Lactococcus lactis and administered orally, could enhance the antibody response against the HpaA antigen approximately 3 fold. These observations strongly suggest that PorA behaves as an effective oral adjuvant.

Situación epidemiológica y cumplimiento de indicadores de la vigilancia de la enfermedad meningocócica / Epidemiologic status and fulfillment of surveillance indicators of meningococcal disease

La enfermedad meningocócica es de distribución mundial y presenta brotes de gran magnitud en el cinturón de la meningitis (África Subsahariana). A partir de 2001, la tendencia de la enfermedad en Chile disminuye, cambiando su presentación a baja endemia. Así, en el 2010 presentó una incidencia de 0,5 por cien mil habitantes. El grupo más afectado son los menores de 5 años, y de éstos, los menores de un año. Además, desde 1994 el serogrupo C fue considerado reemergente, produciendo brotes en 1999 y 2002. Esta enfermedad es de vigilancia universal e inmediata, cuyo sistema de vigilancia contempla indicadores de calidad, que evalúan los componentes clínico, epidemiológico y laboratorio. Este artículo analiza la situación epidemiológica de la enfermedad en Chile y su tendencia mundial, así como el fundamento para el cumplimiento de indicadores que requieren una respuesta oportuna frente al caso sospechoso sin esperar la confirmación de laboratorio.

Meningococcal disease has worldwide distribution and present large-scale outbreaks on the meningitis belt (sub-Saharian Africa). Since 2001, disease trend in Chile decreases, changing its presentation to low endemicity. Thus, 2010 registered an incidence of 0.5 per 100 thousand habitants. The most affected group was < 5 years old, specifically < 1 year old. Besides,since 1994, serogroup C was considered re-emergent, causing outbreaks in 1999 and 2002. This disease considersimmediate and universal surveillance and comprise quality indicators that assess clinical, epidemiological and laboratory components. This article analyze the epidemiological situation in Chile and its world trend, also the fundamental basis for indicator fullfilments that requires a fast response against a suspected case, without waiting for laboratory confirmation.

Deletion of the Correia element in the mtr gene complex of Neisseria meningitidis.

The mtr gene complex in Neisseria meningitidis encodes an efflux pump that is responsible for export of antibacterial hydrophobic agents. The promoter region of the mtrCDE operon harbours an insertion sequence known as a Correia element, and a binding site for the integration host factor (IHF) is present at the centre of the Correia element. It has been suggested that the expression of the mtrCDE operon in meningococci is subject to transcriptional regulation by the IHF and post-transcriptional regulation by cleavage in the inverted repeat of the Correia element. The promoter region of the mtrCDE operon as well as the association of changes at that point with decreased susceptibility to antimicrobial drugs in 606 Neisseria meningitidis strains were analysed in this study. Two different deletions were present in the analysed region. The first one, found in seven strains, corresponded to absence of the Correia element. The second one, affecting the -10 region and first 100 bp of the mtrR gene and present in 57 isolates, was only found in ST-1624 isolates. None of the deletions were associated with decreased susceptibility to antimicrobial drugs. Although most of the meningococcal strains carry the Correia element at that position, its deletion is not an exception.

Flora conjuntival y sensibilidad antibiótica en pacientes a ser sometidos a cirugía de catarata y LASIK / Antibiotic susceptibility of bacterial conjunctival flora isolated from patients undergoing LASIK and cataract surgery

Objetivo: Conocer y proveer de evidencia acerca de la sensibilidad de la flora bacteriana normal de la superficie ocular aislada en dos diferentes grupos sociales y etáreos de pacientes prontos a someterse a cirugía de Catarata y LASIK en nuestro país. Materiales y Métodos: Se cultivaron muestran conjuntivales de 221 pacientes previo a LASIK y de 180 pacientes de un grupo de Cataratas. De haber un cultivo positivo se realizó aislamiento e identificación bacteriana utilizando la técnica de difusión en disco de Kirby-Bauer para doce antibióticos. El análisis estadístico se hizo con chi-cuadrado y el test exacto de Fisher. Resultados: Hubo 66,8 por ciento de cultivos positivos, más frecuentemente gran positivos. SCN fue el aislado en mayor porcentaje (92,2 por ciento) y mostró una alta sensibilidad a Cloramfenicol, Tobramicina, Moxifloxacino y Gatifloxacino, intermedia para Levofloxacino, Gentamicina y Ciprofloxacino y menor para Eritromicina, Oxacilina, Cefalotina y Ceftriaxona (p<0,01). Todos los cultivos fueron sensibles a Vancomicina. No hubo diferencia estadísticamente significativa entre ambos grupos. Conclusiones: 1. Por primera vez nuestros resultados muestran que la flora y sensibilidad antibiótica son similares en pacientes a ser sometidos a LASIK y Catarata, siendo los SCN los más frecuentemente encontrados en ambos grupos de pacientes. 2. Las bacterias más comúnmente aisladas permanecen altamente sensibles a Cloramfenicol, Tobramicina, Moxifloxacino y Gatifloxacino.

Purpose: To know and provide a background on antibiotic susceptibility of normal ocular surface bacterial flora isolated from two different social and age groups of patients undergoing LASIK and cataract surgery in our country. Material and Methods: Conjunctival samples of 221 patients in a LASIK group and 180 patients in a cataract surgery group were cultivated. When there were a positive cultures, isolation and identification of the bacteria were made and antibiotic susceptibility tests were carried out, using the Kirby-Bauer disc diffusion technique for twelve antibiotics. Statistical analysis was performed using chi-square and exact Fisher test. Results: There were 66.8 percent of positive cultures, most of them gram positives. The most frequently isolated bacteria were the CNS (92,2 percent) that showed high sensitivity for Chloramphenicol, Tobramycin, Moxifloxacin and Gatifloxacin, intermedia for Levofloxacin, Gentamicin and Ciprofloxacin and lowest for Erytomycin, Oxacillin, Cefalotin and Ceftriaxone (p<0,01). All the cultures were susceptible to Vancomycin. There was not statistically difference between LASIK and cataract group. Conclusions: 1. For the first time, our results have shown that the conjunctival flora and its sensitivity to antibiotics are similar in the conjunctival flora of the patients undergoing LASIK surgery and Cataract, being CNS the bacterium most frequently found in both different groups of patients. 2. The most frequently isolated conjunctival bacteria remained highly sensitive to Chloramphenicol, Tobramycin, Moxifloxacin and Gatifloxacin.

Laboratory-based surveillance of Streptococcus pneumoniae invasive disease in children in 10 Latin American countries: a SIREVA II project, 2000-2005.

BACKGROUND: For the last 14 years the Pan American Health Organization has been promoting surveillance of invasive pneumococcal disease in Latin American children for better understanding of the disease tendencies regarding capsular types circulation in each country and susceptibility to antimicrobials. METHODS: Laboratory-based surveillance data from 10 Latin American countries collected from 2000 to 2005 were analyzed, including serotype distribution and susceptibility to beta-lactam antibiotics. RESULTS: Although 61 different capsular types were identified during the 6-year surveillance, 13 serotypes accounted for 86% of all isolates. These were consistently the most prevalent throughout the study period with serotype 14 predominating. Diminished susceptibility to penicillin was detected in 38% of all Streptococcus pneumoniae isolates, with the highest prevalence in Dominican Republic and Mexico. Decreased susceptibility to penicillin increased in Brazil and Colombia whereas decreased high resistance rates was recorded in Chile. CONCLUSIONS: These data indicate that 10 countries of the Region continue to have high quality laboratory-based surveillance for pneumococcal disease thus generating valuable information so that healthcare decision makers may prioritize interventions. The heptavalent vaccine will potentially cover from 52.4% to 76.5% of strains causing invasive pneumococcal disease and the 13 valent from 76.7% to 88.3%.

Molecular characterization of invasive serogroup Y Neisseria meningitidis strains isolated in the Latin America region.

OBJECTIVES: To improve the understanding of serogroup Y invasive meningococcal disease (IMD) in Latin America, particularly IMD molecular epidemiology; 166 Y serogroup isolates received at the National Reference Laboratories of Argentina, Brazil, Chile, Colombia, and Costa Rica during 2000-2006 were characterized by their molecular markers. METHODS: This analysis included serological assays to determine serogroup/serotype/serosubtype, DNA sequencing and genotyping of the porB and/or porA genes, multilocus sequence typing (MLST) and fetA allele determination. RESULTS: Sixteen different antigenic combinations were observed. Sixty-two (37.3%) isolates were NT:P1.5 and 36 (21.7%) isolates were 14:NST. Thirty-two different STs appeared, but 3 STs (ST-1624, ST-23, and ST-5770) accounted for 69.9% (116) of the strains. Most of the IMD isolates belonged to the ST-23, ST-167 clonal complexes or the group composed by ST-5770 and related STs. CONCLUSIONS: Isolates obtained in Colombia and Costa Rica were similar to that of the United States, in that most sequence types belonged to the ST-23 clonal complex. IMD isolates found in Argentina appear to be the result of an independent event and did not spread from nearby countries, being the sequence type ST-1624 (ST-167 clonal complex) the most frequently found. We were unable to correlate an antigenic shift of outer membrane proteins with an increase of serogroup Y meningococcal cases in our collection of isolates.

[Resistance to non-beta-lactam antibiotics in the clinical isolates of Streptococcus pneumoniae of children in Latin America. SIREVA II, 2000-2005]. / Resistencia a antibióticos no betalactámicos de aislamientos invasores de Streptococcus pneumoniae en niños latinoamericanos. SIREVA II, 2000-2005.

OBJECTIVE: To examine the development of resistance to erythromycin, chloramphenicol, trimethoprim-sulfamethoxazole (TMP-SMZ), and vancomycin of the invasive isolates of Streptococcus pneumoniae obtained from children in 10 Latin American/Caribbean countries during six years of surveillance. METHODS: Analysis of 8 993 isolates of S. pneumoniae recovered in 2000-2005 from children with invasive infections, who were less than 6 years of age, and from Argentina, Brazil, Chile, Colombia, Cuba, Dominican Republic, Mexico, Paraguay, Uruguay, or Venezuela. Antibiotic susceptibility was determined through the methods established and standardized by the SIREVA project. Multidrug resistance was defined as: resistance to three or more antibiotics of the same class; to the non-beta-lactams analyzed by this study; or, to the beta-lactams evaluated by a previous study, in which 37.8% of these isolates showed decreased susceptibility to penicillin. RESULTS: Some degree of resistance was found to TMP-SMZ and erythromycin (56.4% and 15.4% of the isolates studied, respectively), with 4.6% highly resistant to chloramphenicol. All isolates were susceptible to vancomycin. The highest prevalence of TMP-SMZ resistance was observed in the pneumonia isolates; and that of erythromycin, in cases of sepsis (61.6% and 25.5%, respectively; P < 0.01). The highest prevalence of TMP-SMZ resistance was found in Brazil (71.9%), and that of erythromycin, in Mexico (38.2%) and Venezuela (32.9%). The 14, 6B, 19F, and 23F serotypes were most often associated with resistance to the antibiotics in the study. CONCLUSIONS: High and increasing rates of isolates resistant to TMP-SMZ and erythromycin were observed, as well as a decreasing percentage of isolates resistant to chloramphenicol. These trends highlight differences among the countries studied.

Circulation of Streptococcus pneumoniae clone Colombia 5 ST289 in nine Latin American countries.

OBJECTIVE: To determine genetic relatedness of clone Colombia(5) ST289 with invasive Streptococcus pneumoniae serotype 5 isolates recovered in nine Latin American countries. METHODS: Forty-four invasive S. pneumoniae serotype 5 isolates recovered from children under 5 years of age in Bolivia, Chile, Dominican Republic, Ecuador, Nicaragua, Panama, Paraguay, Peru, and Venezuela were studied. Pulsed-field gel electrophoresis patterns of DNA treated with SmaI restriction enzyme were classified using Tenover's criteria and analyzed with the Fingerprinting II program to determine their genetic relatedness with the Colombian clone. RESULTS: All isolates had a genetic similarity of 78.5% or more with the Colombian clone. Thirteen electrophoretic subtypes derived of pattern A were identified, and five of them (A5, A6, A8, A13, A27) comprised 61.4% of the isolates. CONCLUSIONS: Clone Colombia(5) ST289 is disseminated in Latin America. This is important because S. pneumoniae serotype 5 frequently causes invasive disease in the region and is associated with trimethoprim-sulfamethoxazole resistance.

[Association between genotype screening results obtained by PFGE and PCR for hypervariable regions of the mecA gene in methicillin-resistant Staphylococcus aureus]. / Asociación entre los criterios de clasificación genotípica de Staphylococcus aureus resistente a meticilina que se obtuvo mediante electroforesis en geles de campos pulsantes y mediante reacción en cadena de la polimerasa de regiones hipervariables del gen mecA.

INTRODUCTION: The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has become a major epidemiological problem worldwide. METHODS: We determined the degree of association between the genotype screening results obtained by pulse-field gel electrophoresis (PFGE) and polymerase chain reaction (PCR) for 7 hypervariable DNA regions associated with the mecA gene (HVR-mecA PCR), in the epidemiological analysis of 36 MRSA strains unrelated to nosocomial outbreaks, isolated from hospitalized patients at the County Hospital of Valdivia (Chile). RESULTS: The strains were classified into 15 pulse types (A-O) and 5 genotypes (6, 14, 15, 16, and 17) by PFGE and HVR-mecA PCR, respectively. Most of the strains were grouped in pulse types D, E and I, which presented 85.7% similarity. The most common genotypes were 14 (36.1%) and 15 (33.3%). Each genotype detected by HVR-mecA PCR was distributed in more than one pulse type. The degree of association between genotypic screening by PFGE or HVR-mecA PCR was determined by calculating Cramer's V statistic and the contingency coefficient. In both cases, a value near 1 (0.84 and 0.78, respectively) was obtained, indicating a high association between these genotypic screenings. Thus these are complementary, not exclusionary techniques that can be equally applied. CONCLUSIONS: PFGE is a standardized, high-technology molecular tool with considerable discriminatory power. HVR-mecA PCR is a fast, simple, accessible tool that has lower discriminatory power; nonetheless it can serve as an alternative method for epidemiological research in MRSA strains.

Asociación entre los criterios de clasificación genotípica de Staphylococcus aureus resistente a meticilina que se obtuvo mediante electroforesis en geles de campos pulsantes y mediante reacción en cadena de la polimerasa de regiones hipervariables del gen meca / Association between genotype screening results obtained by PFGE and PCR for hypervariable regions of the mecA gene in methicillin-resistant Staphylococcus aureus

Introducción: El Staphylococcus aureus resistente a meticilina (SARM) es un problema epidemiológico en el ámbito mundial. Métodos: Se determinó el grado de asociación entre los criterios de clasificación genotípica que se obtuvieron mediante PFGE (pulsed-field gel electrophoresis‘electroforesis en geles de campos pulsantes’) y PCR (polymerase chain reaction‘reacción en cadena de la polimerasa’) de 7 regiones hipervariables de ácido desoxirribonucleico asociadas al gen mecA (PCR RHV-mecA) que se aplicaron al análisis de 36 cepas de SARM no relacionadas con brotes epidémicos, aisladas de sujetos que ingresaron en el Hospital Regional de Valdivia, Chile. Resultados: Las cepas se clasificaron en 15 pulsotipos (de la A a la O) y en 5 genotipos (6, 14, 15, 16 y 17) según PFGE y PCR RHV-mecA, respectivamente. La mayoría de las cepas se agruparon en los pulsotipos D, E e I que presentaron un porcentaje de similitud del 85,7%. Los genotipos PCR RHV-mecA de mayor frecuencia fueron el genotipo 14 (36,1%) y el genotipo 15 (33,3%). Cada uno de los genotipos detectados mediante PCR RHV-mecA se distribuyó en más de un pulsotipo. El grado de asociación entre los criterios de clasificación genotípica de PFGE y de PCR RHV-mecA se determinó mediante el coeficiente de contingencia y el coeficiente v de Cramer. En ambos se obtuvo un valor cercano a 1 (0,84 y 0,78, respectivamente) que indicaba una alta asociación entre estos criterios, por tanto, se trataría de técnicas complementarias y no excluyentes que pueden aplicarse indistintamente. Conclusiones: La PFGE representa una herramienta molecular de alta tecnología, estandarización y poder discriminatorio; sin embargo, la tipificación por PCR RHV-mecA es una herramienta simple, accesible y rápida que a pesar de su menor poder discriminatorio puede utilizarse como alternativa en estudios epidemiológicos de las cepas de SARM (AU)

Introduction: The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has become a major epidemiological problem worldwide.Methods: We determined the degree of association between the genotype screening results obtained by pulse-field gel electrophoresis (PFGE) and polymerase chain reaction (PCR) for 7 hypervariable DNA regions associated with the mecA gene (HVR-mecA PCR), in the epidemiological analysis of 36 MRSA strains unrelated to nosocomial outbreaks, isolated from hospitalized patients at the County Hospital of Valdivia (Chile).Results: The strains were classified into 15 pulse types (A-O) and 5 genotypes (6, 14, 15, 16, and 17) by PFGE and HVR-mecA PCR, respectively. Most of the strains were grouped in pulse types D, E and I, which presented 85.7% similarity. The most common genotypes were 14 (36.1%) and 15 (33.3%). Each genotype detected by HVR-mecA PCR was distributed in more than one pulse type. The degree of association between genotypic screening by PFGE or HVR-mecA PCR was determined by calculating Cramer's V statistic and the contingency coefficient. In both cases, a value near 1 (0.84 and 0.78, respectively) was obtained, indicating a high association between these genotypic screenings. Thus these are complementary, not exclusionary techniques that can be equally applied. Conclusions: PFGE is a standardized, high-technology molecular tool with considerable discriminatory power. HVR-mecA PCR is a fast, simple, accessible tool that has lower discriminatory power; nonetheless it can serve as an alternative method for epidemiological research in MRSA strains (AU)

Circulation of Streptococcus pneumoniae clone Colombia5 ST289 in nine Latin American countries / Circulación de Streptococcus pneumoniae clon Colombia5 ST289 en nueve países de América Latina

OBJECTIVE: To determine genetic relatedness of clone Colombia5 ST289 with invasive Streptococcus pneumoniae serotype 5 isolates recovered in nine Latin American countries. METHODS: Forty-four invasive S. pneumoniae serotype 5 isolates recovered from children under 5 years of age in Bolivia, Chile, Dominican Republic, Ecuador, Nicaragua, Panama, Paraguay, Peru, and Venezuela were studied. Pulsed-field gel electrophoresis patterns of DNA treated with SmaI restriction enzyme were classified using Tenover's criteria and analyzed with the Fingerprinting II program to determine their genetic relatedness with the Colombian clone. RESULTS: All isolates had a genetic similarity of 78.5 percent or more with the Colombian clone. Thirteen electrophoretic subtypes derived of pattern A were identified, and five of them (A5, A6, A8, A13, A27) comprised 61.4 percent of the isolates. CONCLUSIONS: Clone Colombia5 ST289 is disseminated in Latin America. This is important because S. pneumoniae serotype 5 frequently causes invasive disease in the region and is associated with trimethoprim-sulfamethoxazole resistance.

OBJETIVO: Determinar la relación genética del clon Colombia5 ST289 con los aislamientos invasores de Streptococcus pneumoniae serotipo 5 provenientes de nueve países latinoamericanos. MÉTODOS: Se estudiaron 45 aislamientos invasores de Streptococcus pneumoniae serotipo 5 procedentes de niños menores de 5 años de Bolivia, Chile, Ecuador, Nicaragua, Panamá, Paraguay, Perú, República Dominicana y Venezuela. Los patrones en electroforesis en gel de campo pulsante del ADN tratado con la enzima de restricción SmaI se clasificaron mediante el criterio de Tenover y se analizaron con el programa Fingerprinting II para determinar su relación genética con el clon colombiano. RESULTADOS: Todos los aislamientos tuvieron una similitud genética de 78,5 por ciento o mayor con el clon colombiano. Se identificaron 13 subtipos electroforéticos derivados del patrón A y cinco de ellos (A5, A6, A8, A13 y A27) constituyeron 61,4 por ciento de los aislamientos. CONCLUSIONES: El clon Colombia5 ST289 está diseminado por América Latina. Esto es importante ya que S. pneumoniae serotipo 5 es causa frecuente de enfermedades invasoras en la Región y está asociado con la resistencia a trimetoprim-sulfametoxazol.

Age- and serotype-specific pediatric invasive pneumococcal disease: insights from systematic surveillance in Santiago, Chile, 1994--2007.

BACKGROUND: We monitored pediatric invasive pneumococcal disease (IPD) in Santiago, Chile, from 1994 to 2007. METHODS: Three related data sets were generated: (1) IPD cases requiring hospitalization, 1994--2007; (2) cases of bacteremia detected among febrile patients aged 0-35 months seen in emergency departments, 2000--2007; and (3) nasopharyngeal carriage of pneumococcal serotypes, determined from repetitive culturing, among 524 newborns followed up through age 23 months. RESULTS: Of 2369 IPD cases requiring hospitalization, 1878 (79.3%) occurred in those aged 0-59 months, and 1200 (50.7%) occurred in those aged 6-35 months. Among infants aged 0-5 months, meningitis and sepsis comprised 48.4% of all IPD cases (serotype 5 predominated); among those 6-35 months old, 522 (43.5%) of 1200 cases were bacteremic pneumonia (serotype 14 predominated). Serotype 1 peritonitis was common among 5-14-year-old girls. Meningitis and sepsis exhibited high case fatality rates (14%-29%) among all ages. Remarkably, 34 (28.8%) of 118 children with sepsis died, versus 1 fatality (0.4%) among 276 children hospitalized with bacteremia without a focus (P < .001, Fisher's exact test). Serotype 5 was significantly more common among hospitalized patients < 36 months of age, whereas serotype 18C was overrepresented among ambulatory patients. The annual incidence of serotype 14 was stable; those of serotypes 1 and 5 fluctuated markedly. Serotypes 14, 5, and 1 were overrepresented among invasive compared with nasopharyngeal isolates. CONCLUSIONS: Clinical syndromes of IPD and predominant serotypes vary with age.

[Molecular characterization of Chilean isolates of streptococcus agalactiae]. / Caracterización molecular en aislados chilenos de Streptococcus agalactiae.

BACKGROUND: Streptococcus agalactiae is the main causing organism of invasive infections such as sepsis and meningitis in the newborn. AIM: To perform a genotype characterization of Streptococcus agalactiae strains coming form invasive infections of newborns and colonized pregnant women. MATERIAL AND METHODS: A group of 58 strains not related epidemiologically isolated from colonized pregnant women and invasive infections in newborns, were studied. Pulsed field electrophoresis (PFGE) and polymerase chain reaction amplification of hylB and IS 1,548 genes, as possible virulence markers, were performed. RESULTS: Among the studied strains, 37 genetic subtypes were observed. There were nine groups of identical PFGE patterns. Three corresponded to serotype la and six to serotype III. An erythromycin and clindamycin resistant clone was identified in three colonized women and a newborn with sepsis, which were not epidemiologically related. The hylB gene was equally present in cases of neonatal meningitis or colonized pregnant women. CONCLUSIONS: There was a great degree of polymorphism among the studied strains. The ample presence of hylB gene and the absence of the insertion element IS1548 in the hylB gene in invasive and colonizing strains, indicates that both groups of strains are potentially pathogenic.

Caracterización molecular en aislados chilenos de Streptococcus agalactiae / Molecular characterization of Chilean isolates of streptococcus agalactiae

Streptococcus agalactiae is the main causing organism of invasive infections such as sepsis and meningitis in the newborn. Aim: To perform a genotype characterization of Streptococcus agalactiae strains coming form invasive infections of newborns and colonized pregnant women. Material and methods: A group of 58 strains not related epidemiologically isolated from colonized pregnant women and invasive infections in newborns, were studied. Pulsed field electrophoresis (PFGE) and polymerase chain reaction amplification of hylB and IS 1548 genes, as possible virulence markers, were performed. Results: Among the studied strains, 37 genetic subtypes were observed. There were nine groups of identical PFGE patterns. Three corresponded to serotype la and six to serotype III. An erythromycin and clindamycin resistant clone was identified in three colonized women and a newborn with sepsis, which were not epidemiologically related. The hylB gene was equally present in cases of neonatal meningitis or colonized pregnant women. Conclusions: There was a great degree of polymorphism among the studied strains. The ample presence of hylB gene and the absence of the insertion element IS1548 in the hylB gene in invasive and colonizing strains, indicates that both groups of strains are potentially pathogenic.

Evolution of an international external quality assurance model to support laboratory investigation of Streptococcus pneumoniae, developed for the SIREVA project in Latin America, from 1993 to 2005.

In 1993 the Pan American Health Organization initiated a laboratory-based surveillance system, called the SIREVA project, to learn about Streptococcus pneumoniae invasive disease in Latin American children. In 1994, National Laboratories in six countries were trained to perform serotyping and antibiotic susceptibility testing using broth microdilution to determine the MIC for specified antibiotics. An international External Quality Assurance (EQA) program was developed to monitor and support ongoing laboratory performance. The EQA program was coordinated by the National Centre for Streptococcus (NCS), Edmonton, Canada, and included external proficiency testing (EPT) and a validation process requiring regular submission of a sample of isolates from each laboratory to the NCS for verification of the serotype and MIC. In 1999, the EQA program was decentralized to use three of the original laboratories as regional quality control centers to address operational concerns and to accommodate the growth of the laboratory network to more than 20 countries including the Caribbean region. The overall EPT serotyping accuracies for phase I (1993 to 1998) and phase II (1999 to 2005) were 88.0 and 93.8%, respectively; the MIC correlations within +/-1 log(2) dilution of the expected result were 83.0 and 91.0% and the interpretive category agreements were 89.1 and 95.3%. Overall, the validation process serotyping accuracies for phases I and II were 81.9 and 88.1%, respectively, 80.4 and 90.5% for MIC agreement, and 85.8 and 94.3% for category agreement. These results indicate a high level of testing accuracy in participating National Laboratories and a sustained increase in EQA participation in Latin America and the Caribbean.

[Retrospective assessment of laboratory surveillance for invasive Streptococcus pneumoniae isolates from adults of the Metropolitan Region (Chile): 2000-2006]. / Evaluación retrospectiva de la vigilancia de Streptococcus pneumoniae causante de enfermedades invasoras en adultos de la Región Metropolitana-Chile: 2000-2006.

This study assessed the performance of the national norm for laboratory surveillance of invasive Streptococcus pneumoniae in adults of the Metropolitan Region (Chile). Material and Methods. We reviewed all notifications of isolates from patients > 15 years of age received by the Institute of Public Health of Chile during the period 2000-2006, submitted by health care facilities of the study region. We also reviewed the original records of sterile fluid cultures, in 14 public adult hospitals. Results. We found documentation of 1429 invasive S. pneumoniae isolates recovered from adult patients, including 1095 reported and 334 not-reported isolates. A 33% under-reporting rate was estimated for the 14 hospitals where local laboratory records were inspected. Age and clinical diagnosis were omitted in 23% and 78% of the notifications, respectively. Among 303 isolates from patients > 65 years of age that were investigated with Quellung reaction, 235 (78%) had capsular serotypes represented in the 23-valent polysaccharide vaccine. Conclusions. The Ministry of Health of Chile announced implementation of 23-valent vaccine immunization program for the elderly. In the perspective of future evaluations of the impact of this intervention, the results of this study indicate the need of reinforcing adherence and improving the quality of notifications of invasive S. pneumoniae.

Challenges in the control of gonorrhea in South America and the Caribbean: monitoring the development of resistance to antibiotics.

OBJECTIVE: : The objective of this study was to ascertain the antimicrobial susceptibility of Neisseria gonorrhoeae isolates from 6 South American and 13 Caribbean countries participating in the Gonococcal Antimicrobial Surveillance Program (GASP) from 1990 to 1999. STUDY: : A GASP network of laboratories was launched in the Americas and the Caribbean during the 1990s. Standardized methods and interpretative criteria were established for the isolation of N. gonorrhoeae, strain identification, and determination, and quality control of antimicrobial susceptibility. RESULTS: : Two countries (Argentina and Uruguay) maintained continuous surveillance during the study period. Some countries gathered data periodically and several others were unable to initiate antimicrobial surveillance as a result of lack of resources. The percentage of penicillin-resistant N. gonorrhoeae isolated in the region over the decade varied considerably (1.0-11.9% carried chromosomal resistance and 17.9-38.8% produced beta-lactamase) with an overall trend to declining numbers of penicillin-resistant isolates. For tetracycline, 7.4% to 36.3% carried chromosomal resistance, whereas 12.0% to 27.4% carried plasmid-mediated resistance. There were no reports of ciprofloxacin-resistant isolates, although N. gonorrhoeae with decreased susceptibility to ciprofloxacin and azithromycin as well as spectinomycin-resistant isolates were identified in some countries.