Phenotypic and genotypic characterization of oxacillin-susceptible and mecA positive Staphylococcus aureus strains isolated in Uruguay.

The aim of this study was to characterize phenotypically and genotypically 27 mecA positive Staphylococcus aureus strains with oxacillin MICs of ≤2µg/ml by Vitek 2, isolated in different regions of Uruguay. Susceptibility to oxacillin and cefoxitin was studied by gradient diffusion, disk diffusion to cefoxitin, and Phoenix and MicroScan systems. PBP2a was determined. SCCmec typing was performed and the isolates were compared by PFGE. Twenty-six isolates were susceptible to oxacillin; one strain was susceptible to cefoxitin by disk diffusion and 3 strains by gradient diffusion. Phoenix and MicroScan panels detected methicillin resistance in 25 and 27 strains, respectively. Twenty-six strains tested positive for PBP2a. Twenty-six strains carried SCCmec V and 24 belonged to pulsotype A. One strain carried SCCmec IV and did not belong to pulsotype A. Cefoxitin disk diffusion test and PBP2a detection correctly identified 26 of these 27 strains as MRSA. PFGE results suggest the dissemination of a cluster of MRSA carrying SCCmec V.

[Pneumococcal invasive disease in newborns before and after 7-valent and 13-valent universal pneumococcal vaccination in Uruguay]. / Enfermedad neumoccócica invasora en recién nacidos, antes y después de la vacunación universal con vacuna conjugada 7 y 13 valente en Uruguay.

INTRODUCTION: Streptococcus pneumoniae infections are not frequent in neonates, but presents high morbidity and mortality. In 2008, the 7-valent pneumococcal conjugate vaccine (PCV) was introduced in the childhood vaccination schedule and then replaced by 13-valent PCV in 2010. First dose is given at 2 months of age. Protection of neonates is expected with universal vaccination. OBJECTIVE: To describe the clinical presentation, microbiology and outcome of neonates with pneumococcal invasive infections (PII) detected in two hospitals in Uruguay in 2001-2007 (pre-vaccination), 2008 (intervention) and 2009-2013 (post-vaccination). METHODS: A descriptive, retrospective study was done at Pereira Rossell Hospital and Paysandú Hospital. All isolates of S. pneumoniae obtained from normally sterile fluids were included. Data were obtained from the clinical records and the microbiology laboratory. A statistical analysis with absolute frequencies, relative, rates and relative risk was performed. RESULTS: 25 neonates were enrolled with diagnosis of: sepsis (n = 13), meningitis (n = 9), bacteremia (n = 1), pneumonia with empyema (n = 1) and pneumonia (n = 1). The incidence of PII in the prevaccination period was 19/25, with a rate of 0.30/1,000 births, compared to post-vaccination rate of 0.04/1,000. The relative risk was 5.9. 6/20 (30%) cases of death were reported (meningitis n = 3; sepsis n = 2; empyema n = 1). Most common serotypes were 5 and 1 (14/25) and 24/25 strains were susceptible to penicillin. DISCUSSION: The symptoms were indistinguishable to infections caused by other pathogens. PII cases decreased and no deaths occurred in the post-vaccination period. No increase in non-vaccine serotypes was observed.

Intracellular bacteria in the pathogenesis of Escherichia coli urinary tract infection in children.

BACKGROUND: Uropathogenic Escherichia coli (UPEC) is the most common agent of urinary tract infection (UTI). The classic model of pathogenesis proposes the ascent of UPEC by the urethra and external adherence to the urothelium. Recently, the ability of UPEC to invade urothelial cells and to form intracellular bacterial communities (IBCs) has been described. METHODS: The objective of the present study was to determine the presence of intracellular bacteria (IB) in children with UTI caused by E. coli and to characterize its virulence attributes and its relation with clinical outcomes. One hundred thirty-three children with E. coli UTI who attended a reference children's hospital between June and November 2012 were included. Urine samples were analyzed by optical and confocal microscopy looking for exfoliated urothelial cells with IB. Phylogenetic group and 24 virulence factors of UPEC were determined using multiplex polymerase chain reaction. Medical records were analyzed. RESULTS: The presence of IB was detected in 49 of 133 (36.8%) samples by confocal microscopy, in 30 cases as IBC, and in 19 as isolated intracellular bacteria (IIB). Only 50% of these cases could be detected by light microscopy. Seventy-four medical records were analyzed, 34 with IBC/IIB, 40 without IB. Any virulence gene was associated with IBC/IIB. The presence of IBC/IIB was associated with recurrent UTI (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.3-9; P = .017), especially in children without urinary tract functional or morphological abnormalities (OR, 8.0; 95% CI, 2.3-27.4; P = .000). IBCs were associated with lower urinary tract syndrome (OR, 3.6; 95% CI, 1.1-11.8; P = .05) and absence of fever (P = .009). CONCLUSIONS: IBCs/IIB could explain a high proportion of children with recurrent UTI.

[Invasive Streptococcus pyogenes diseases 2005-2013: Pediatric Hospital Pereira Rossell Uruguay]. / Enfermedades invasoras por Streptococcus pyogenes 2005-2013: Hospital Pediátrico del Centro Hospitalario Pereira Rossell, Uruguay.

INTRODUCTION: Streptococcus pyogenes infection causes a wide spectrum of clinical manifestations. Invasive disease (ID) is defined by the isolation of the microorganism from sterile sites. OBJECTIVE: To analyze the clinical, epidemiological and molecular characteristics of ID by S.pyogenes in children hospitalized at Pediatric Hospital Pereira Rossell, from January 2005 to January 2013. MATERIALS AND METHODS: A descriptive retrospective study was done in cases with isolation of S.pyogenes from sterile sites. Epidemiological variables, disease characteristics, laboratory parameters, treatment regimen received, hospitalization days and clinical outcome were analyzed. The presence of 4 genes encoding for virulence factors and chromosome profile studied by pulsed-field electrophoresis were done in the isolated strains. RESULTS: A total of 42 cases (rate: 4.6 out of 10,000 admissions) were detected, from which 32 were analyzed. Average age was 44.7 months (14/32 < 2 years of age). In 5 cases, the portal of entry was identified. Clinical presentations were: osteoarticular infections (n = 15), shock (n = 6), skin and soft-tissue infections (n = 5), pneumonia (n = 3) and bacteremias (n = 3). Twenty cases required surgical procedures and 13 required intensive care admission. Average hospital stay was 17 days and one patient died. Molecular studies were performed in five strains; 4 different toxin profiles and pulsotypes were identified. DISCUSSION: The incidence of ID at our hospital is similar to other series in the region. A better knowledge of clinical presentation and its relation with molecular characteristics represents a challenge.

Detection of Vancomycin Resistance among Methicillin-Resistant Staphylococcus aureus Strains Recovered from Children with Invasive Diseases in a Reference Pediatric Hospital.

Vancomycin is the cornerstone in treating methicillin-resistant Staphylococcus aureus (MRSA) infections. However, therapeutic failures can occur when MRSA strains with decreased susceptibility to glycopeptides (DSG) are involved. The aim of this study was to detect and characterize DSG in MRSA recovered from children with invasive diseases at a reference pediatric hospital between 2009 and 2019. Fifty-two MRSA strains were screened using agar plates with vancomycin 3 and 4 mg/L (BHI-3 and BHI-4); the VITEK2 system; and standard and macro E-tests. Suspicious hVISA were studied by population analysis profiling-area under the curve (PAP-AUC), and wall thickness was analyzed by transmission electron microscopy. Neither VRSA nor VISA were detected in this set. As only three strains met the hVISA criteria, the PAP-AUC study included 12 additional MRSA strains that grew one colony on BHI-4 plates or showed minimum inhibitory concentrations of vancomycin and/or teicoplanin ≥ 1.5 mg/L. One strain was confirmed as hVISA by PAP-AUC. The wall thickness was greater than the vancomycin-susceptible control strain; it belonged to ST30 and carried SCCmec IV. As expected, a low frequency of hVISA was found (1.9%). The only hVISA confirmed by PAP-AUC was not detected by the screening methods, highlighting the challenge that its detection represents for microbiology laboratories.

[Treatment failure due to acquisition of antibiotic resistance: report of two clinical cases]. / Fallo terapéutico por resistencia antibacteriana intra-tratamiento, a propósito de dos casos clínicos.

OBJECTIVE: We describe two cases of treatment failure due to intra-treatment acquisition of antibiotic resistant microorganisms with the aim of highlighting the possible molecular mechanisms by which treatment failure occurred. PATIENTS AND METHODS: We analyzed the clinical histories and the isolates obtained from 2 patients, one with a urinary tract infection (UTI) by E. coli, initially treated with cefuroxim (to which the isolate was susceptible), and another with osteoarthritis (OA) treated initially with meropenem plus vancomycin, developing K. pneumoniae susceptible to meropenem. During treatment, in both patients, resistant microorganisms were isolated, and empirical therapy was modified, initially with ceftriaxone and afterwards meropenem in case 1, and adding amikacin in case 2. Both strains (per patient) were compared by PFGE and resistance genes were sought by PCR. RESULTS: Regarding the UTI, the initial strain acquired an IncFIB SHV-5-producing plasmid. In the OA case, the initial susceptible strain was substituted by a CTX-M-9 and AadB-AadA2-Aac(6')Ib-producing K. pneumoniae.

First human isolate of Salmonella enterica serotype Enteritidis harboring blaCTX-M-14 in South America.

We studied a clinical isolate of Salmonella enterica serotype Enteritidis showing resistance to oxyiminocephalosporins. PCR analysis confirmed the presence of bla(CTX-M-14) linked to IS903 in a 95-kb IncI1 conjugative plasmid. Such a plasmid is maintained on account of the presence of a pndAC addiction system. Multilocus sequence typing (MLST) analysis indicated that the strain belongs to ST11. This is the first report of bla(CTX-M-14) in Salmonella Enteritidis of human origin in South America.

Extended-spectrum ß-lactamases and plasmid-mediated quinolone resistance in enterobacterial clinical isolates in the paediatric hospital of Uruguay.

OBJECTIVES: To analyse the prevalence of resistance to ß-lactams and plasmid-mediated quinolone resistance in Enterobacteriaceae in the paediatric hospital of Uruguay. METHODS: A total of 368 enterobacterial isolates collected between 1 May and 30 November 2009 were studied for the presence of extended-spectrum ß-lactamases (ESBLs), qnr alleles and aac(6')Ib by phenotypic and molecular methods. The genomic context and transferability of ß-lactamase and qnr genes were examined by PCR and conjugation, respectively. RESULTS: The proportion of inpatients having an infection caused by ESBL-producing enterobacteria was 0.23% (16/7073) in paediatrics wards, 0.64‰ (3/4696) in the neonatology department and 0.03‰ (1/32 557) in the emergency department. ESBL-carrying enterobacteria constituted a total of 21.6% (16/74), 13% (3/23) and 0.37% (1/271) when samples were obtained from paediatrics wards, the neonatology department and the emergency department, respectively. Overall, CTX-M-2 (n = 7), CTX-M-9 (n = 3), CTX-M-8 (n = 2), CTX-M-15 (n = 1), SHV-5 (n = 5) and SHV-2 (n = 2) ß-lactamases were detected. Thirteen out of 20 ESBL-producing isolates also carried the aac(6')Ib gene, and the cr variant was detected in one of them. qnr alleles were detected in four isolates comprising two qnrA1 genes, a qnrB8-like variant and a new qnrB gene showing 26 amino acid differences from QnrB1. CONCLUSIONS: The proportion of ESBL-producing enterobacteria in Uruguay's paediatric hospital during the study period was 2.3 per 1000 hospitalized patients. The number of different microorganisms detected, as well as the various EBSLs, suggests the occurrence of sporadic episodes instead of nosocomial outbreaks. Nevertheless, the presence of new resistance genes reinforces the necessity for permanent surveillance programmes.

First three Escherichia coli isolates harbouring mcr-1 in Uruguay.

OBJECTIVE: This report described the first Escherichia coli (E. coli) isolates harbouring mcr-1 in Uruguay. METHODS: Three E. coli isolates were obtained from blood, urine and rectal swabs from different patients in two hospitals. Extended-spectrum ß-lactamases (ESBL), plasmid-encoded (pAmpC) ß-lactamases, plasmid-mediated quinolone resistance (PMQR) genes, class 1 integrons, and mcr-1, mcr-2 and mcr-3 were sought and characterised in three E. coli isolates. Transfer of resistance determinants was assessed by conjugation. Clonality was analysed by multilocus sequence typing. RESULTS: All isolates were categorised as being colistin-resistant and the mcr-1 gene was detected. Two isolates were also resistant to oxyimino cephalosporins: one on account of blaCMY-2 and the other due to blaCTX-M-15, the latter also harbouring transferable quinolone-resistance genes (aac(6')Ib-cr and qnrB). All mcr-1 genes were transferred by conjugation to recipient strains. The mcr-1-bearing isolates belonged to sequence types ST10, ST93 and ST5442. CONCLUSIONS: ST10 is considered as a high-risk clone worldwide. This type of mcr-1-harbouring clone is a major concern for human and animal health and must be under close surveillance. This study detected the presence of mcr-1 for the first time in Uruguay, albeit in an allodemic manner, associated with different antibiotic-resistance genes and from diverse clinical contexts. Considering that colistin is often the last therapeutic option available for multidrug-resistant Gram-negative bacilli infections, it is important to maximise precautions to avoid dissemination of isolates carrying mcr-1.

Haemophilus influenzae type b invasive infections in children hospitalized between 2000 and 2017 in a Pediatric Reference Hospital (PRH).

BACKGROUND: Uruguay incorporated the conjugate vaccine against Haemophilus influenzae b (Hib) in 1994. In 2008, the vaccine was changed from one with natural conjugated capsular polysaccharide to one with a synthetic polysaccharide component. We describe the frequency and characteristics of invasive Hib infections in children hospitalized in a Pediatric Reference Hospital (PRH) between January 1st, 2000 and December 31st, 2017. METHODS: Sterile site Hib isolations from hospitalized children were included. Clinical and microbiological characteristics were analyzed. Favorable conditions for the infection were considered: incomplete immunization, immunodeficiencies and associated pathologies. Two periods are described: 1, prior to vaccine change (1/1 st/2000- 12/31/08) and 2, post-change (1/1 st/09- 12/31st/17). RESULTS: 45 children were hospitalized: 5 in the first period and 40 in the second. The hospitalization rate per 10,000 discharges was 0.41 (95% CI 0.05-0.77) and 4.2/10,000 (95% CI 2.89-5.48), respectively (p < 0.01). The diagnoses at discharge were: meningitis/ventriculitis (20), pneumonia (16), bacteremia (3), epiglottitis (1), arthritis (1), cellulitis (3) and obstruction of the upper airway (1). Four children presented comorbidities. Twenty seven received less than 3 doses of anti-Hib vaccination and 18 were properly vaccinated (2 were immunodeficient). The median hospitalization was 14 days, 18 children required intensive therapy. CONCLUSIONS: Observed change may be due to: incomplete primary series, inhomogeneous vaccine coverage and immunogenicity of the synthetic polysaccharide. To reduce this public health problem, epidemiological surveillance.

Genomic and phenotypic variation in epidemic-spanning Salmonella enterica serovar Enteritidis isolates.

BACKGROUND: Salmonella enterica serovar Enteritidis (S. Enteritidis) has caused major epidemics of gastrointestinal infection in many different countries. In this study we investigate genome divergence and pathogenic potential in S. Enteritidis isolated before, during and after an epidemic in Uruguay. RESULTS: 266 S. Enteritidis isolates were genotyped using RAPD-PCR and a selection were subjected to PFGE analysis. From these, 29 isolates spanning different periods, genetic profiles and sources of isolation were assayed for their ability to infect human epithelial cells and subjected to comparative genomic hybridization using a Salmonella pan-array and the sequenced strain S. Enteritidis PT4 P125109 as reference. Six other isolates from distant countries were included as external comparators.Two hundred and thirty three chromosomal genes as well as the virulence plasmid were found as variable among S. Enteritidis isolates. Ten out of the 16 chromosomal regions that varied between different isolates correspond to phage-like regions. The 2 oldest pre-epidemic isolates lack phage SE20 and harbour other phage encoded genes that are absent in the sequenced strain. Besides variation in prophage, we found variation in genes involved in metabolism and bacterial fitness. Five epidemic strains lack the complete Salmonella virulence plasmid. Significantly, strains with indistinguishable genetic patterns still showed major differences in their ability to infect epithelial cells, indicating that the approach used was insufficient to detect the genetic basis of this differential behaviour. CONCLUSION: The recent epidemic of S. Enteritidis infection in Uruguay has been driven by the introduction of closely related strains of phage type 4 lineage. Our results confirm previous reports demonstrating a high degree of genetic homogeneity among S. Enteritidis isolates. However, 10 of the regions of variability described here are for the first time reported as being variable in S. Enteritidis. In particular, the oldest pre-epidemic isolates carry phage-associated genetic regions not previously reported in S. Enteritidis. Overall, our results support the view that phages play a crucial role in the generation of genetic diversity in S. Enteritidis and that phage SE20 may be a key marker for the emergence of particular isolates capable of causing epidemics.

[Antibiotic consumption and antimicrobial susceptibility evolution in the Centro Hospitalario Pereira Rossell in methicillin resistant Staphylococcus aureus era]. / Evolución del consumo de antibióticos y de la susceptibilidad antimicrobiana en el Centro Hospitalario Pereira Rossell en la era de Staphylococcus aureus resistente a meticilina.

INTRODUCTION: In the past few years, an increase in methicillin resistant-not multiresistant Staphylococcus aureus was observed in Uruguay among children with community acquired infections. Recommendations for empiric antibiotic treatment required adjustments and new national guidelines were recommended in July 2004. Adherence to these guidelines was indirectly performed by monitoring antibiotic consumption and antimicrobial susceptibility patterns in Uruguay. OBJECTIVE: To describe and compare antibiotic consumption and antimicrobial susceptibility of Staphylococcus aureus in a Pediatric Hospital of the Centro Hospitalario Pereira Rossell (PH-CHPR) between 2001 and 2006. METHODS: Antibiotic consumption in hospitalized children was calculated using the Defined Daily Dose per 100 bed-days (DDD/100). Reference values were obtained from the World Health Organization Collaborating Center for Drug Statistics Methodology of. Consumption. Data were obtained using the WinPharma programme of the Pharmacy Department of CHPR. The fraction of annual occupancy of hospital beds was obtained from the Statistic Division of CHPR. Antibiotic consumption was evaluated between 2001 and 2006 and expressed as DDD/100 and percent change. Antimicrobial susceptibility was evaluated using CHPR's Microbiology Laboratory data during the same time period. RESULTS: After 2003 a significant increase in consumption of clindamycin, ceftriaxone, trimethoprim-sulphamethoxazole, cefuroxime, vancomycin and gentamycin was observed, except for cephradine. Consumption of clindamycin, ceftriaxone and trimethoprim-sulphamethoxazole showed the highest increase (6.15%; 1.44% and 1.17% respectively). Detection of Staphylococcus aureus increased significantly mostly from skin and soft tissue infections. Oxacillin susceptibility of S. aureus strains obtained from different sites had a significant and persistent decrease after 2003 (from 81 % during year 2001 to 40% in year 2006 (p < 0.05). Susceptibility to others antibiotics did not decrease. Between 2004 and 2006 the "D effect" decreased from 28% to 21 %. Antimicrobial susceptibility patterns did not differ by site of infection. CONCLUSIONS: Methicillin resistant-not multiresistant Staphylococcus aureus has established itself as a regular community pathogen in Uruguayan children. Changes in antimicrobial consumption patterns reflect the impact of this pathogen in clinical practice and the overall adherence to new recommendations. This change was not associated with an increase in antibiotic resistance. Clindamycin is an alternative treatment although Clindamycin inducible resistance is a worry. Continuous monitoring of antibiotic consumption and local susceptibility patterns are required to promote rational use of antibiotics.

[Incidence of group B streptococcal early-onset sepsis in infants born at Centro Hospitalario Pereira Rossell between 2007-2015]. / Incidencia de sepsis precoz por Streptococcus agalactiae en recién nacidos del Centro Hospitalario Pereira Rossell en el período 2007-2015.

BACKGROUND: Group B Streptococcus (GBS) disease remains the leading cause of early-onset sepsis (EOS) in developed countries despite effective prophylaxis strategies. AIMS: To describe the incidence, clinical features and mortality of GBS EOS in infants born at Centro Hospitalario Pereira Rossell (CHPR) and analyse failure of adherence to prevention strategies. METHODS: Retrospective review of EOS cases between 2007 and 2015 collected from the bacteriology laboratory database. RESULTS: Fifteen cases of GBS EOS were identified, with an incidence of 0.23% during the study period. Intrapartum antibiotic prophylaxis (IAP) was not administered in any of the cases. All infants were symptomatic within the first 15 hours of life, mainly due to respiratory signs (80%). In one case, GBS was isolated from spinal fluid. Mortality rate was 20%. All deaths occurred in the first 24 hours of life, corresponding two thirds to preterm infants. CONCLUSION: The incidence of GBS EOS at CHPR was similar to other centers where IAP is implemented. Better adherence to prophylaxis strategies could reduce the incidence.

[Etiology and evolution of the osteoarticular infections. 2009-2015: Pediatric Hospital Pereira Rossell Uruguay]. / Etiología y evolución de las infecciones osteo-articulares 2009-2015: Hospital Pediátrico del Centro Hospitalario Pereira Rossell, Uruguay.

BACKGROUND: The most frequent osteoarticular infections (OAI) etiological agent is Staphylococcus aureus. The prevalence of other microorganisms has changed after the introduction of new vaccines. AIM: To describe the etiology and evolution of the OAIs in children hospitalized in Pediatric Hospital Pereira Rossell between 2009 and 2015. PATIENTS AND METHODS: Joint fluid and bone puncture studies of hospitalized children suspected of OAI. Epidemiological characteristics, isolated microorganisms, complementary tests, initial treatment, complications, and days of hospitalization were analyzed. RESULTS: 335 patients; the etiology was established in 113. Clinical data could be analyzed in 87 cases. The average age was 6.1 years. They corresponded to: methicillin-sensitive S. aureus (n: 47), community-acquired methicillin-resistant S. aureus (CA-MRSA) (n: 11), Streptococcus pyogenes (n: 6), Streptococcus pneumoniae (n: 1), Haemophilus influenzae type b (n: 2), Gram-negative bacilli (n: 9), Kingella kingae (n: 1) others (n: 6). In 4 cases, more than one microorganism was isolated. CA-MRSA infections were more serious. DISCUSSION: A decrease is observed in the number of CA-MRSA isolates. A fact to be highlighted is the impact of universal vaccination against S. pneumoniae and H. influenzae type b. It is a finding to be monitored the increasing number of Gram-negative bacilli isolates.

Enfermedades invasoras por Streptococcus pyogenes en población pediátrica. Caracterización clínico-molecular 2014-2020 / Invasive diseases due to Streptococcus pyogenes in the pediatric population. Clinical-molecular characterization 2014-2020

INTRODUCCIÓN: Streptococcuspyogenes (EGA) es agente de enfermedad invasora (EI); su alta morbimortalidad exige vigilancia epidemiológica. OBJETIVO: Describir características clínicas y epidemiológicas de niños hospitalizados con EI por EGA en un centro de referencia de Uruguay del 1/1/2014 al 31/12/2020 incluyendo el estudio de los factores de virulencia encontrados en las cepas aisladas. MATERIALES Y MÉTODOS: Descriptivo y retrospectivo. Definición de caso: aislamiento de EGA. en sitios estériles. Variables: epidemiológicas, clínicas, laboratorio, tratamiento y evolución. Se tipificó por secuenciación del gen emm. Se obtuvieron perfiles cromosómicos por digestión del ADN con la enzima SmaI. Presencia de los genes que codifican SpeB, SpeA, SpeC y Ssa, y susceptibilidad a antimicrobianos. RESULTADOS: Tasa de admisiones: 3,98/10.000. Se incluyeron 22 pacientes; infección osteoarticular (n = 11), infección pleuropulmonar (n = 6), absceso no cutáneo (n = 4) y aislamiento en sangre (n = 1). Media de edad: 44 meses; 8 fueron graves, siendo su media de edad menor (16 meses) Todas los casos con neumonías fueron graves y un paciente falleció. Se secuenciaron 12 cepas: 5 emm1 (4 emm 1.29 y 1 emm 1) y 1 de cada uno de los siguientes: emm 6.4, emm 81, emm12, emm28, emm 22, emm 87, emm 11. Todas eran SpeB+. Perfiles de toxinas: SpeA+SpeC-Ssa-(5), SpeA-SpeC+Ssa-(4) SpeA-SpeC-Ssa-(2) y SpeA-SpeC+Ssa+ (2). CONCLUSIONES: Este estudio permite dar continuidad a un estudio previo. Se logró mayor tipificación de EGA. que puede contribuir a su conocimiento clínico molecular. No hubo registro de pacientes con diagnóstico de SST ni de fascitis necrosante, a diferencia de la serie anterior.

BACKGROUND: Streptococcus pyogenes (GAS) is an agent of invasive disease (ID); its high morbidity and mortality requires epidemiological surveillance. AIM: To describe the clinical and epidemiological characteristics of children hospitalized with ID due to GAS in a reference center in Uruguay from January 1-2014 to December 31-2020, including a study of virulence factors. METHODS: Descriptive and retrospective. Case definition: Isolation of GAS in sterile sites. Variables: epidemiological, clinical, laboratory, treatment and evolution. Strains were typified by sequencing of the emm gene. Chromosomal profiles were obtained by digestion of the DNA. with the Smal enzyme. Presence of SpeB, SpeA and SpeC genes and susceptibility to antibiotics were performed. RESULTS: Admissions rate: 3.98/10,000. 22 patients were included; osteoarticular infection (n = 11), pleuropulmonary infection (n = 6), non-cutaneous abscess (n = 4) and blood isolation (n = 1). Mean age: 44 months; 8 cases were severe, their mean age was lower (16 months). All pneumonia cases were severe and one patient died. Twelve strains were sequenced: 5 emm1 (4 emm1.29 and 1 emm1) and 1 of each: emm6.4, emm81, emm 12, emm28, emm 22, emm 87, emm 11. All were SpeB+. Toxin profiles: SpeA+SpeC-Ssa-(5), SpeA-SpeC+Ssa-(4) SpeA-SpeC-Ssa-(2) and SpeA-SpeC+Ssa+(2). CONCLUSIONS: This study allows to give continuity to a previous study. Greater typing of GAS was achieved, which may contribute to its molecular clinical knowledge. There was no record of patients diagnosed with TSS or necrotizing fascitis, unlike the previous series.

Full-Genome Sequence of Listeria monocytogenes Strain H34, Isolated from a Newborn with Sepsis in Uruguay.

The foodborne pathogen Listeria monocytogenes causes severe disease mainly in the vulnerable populations of the young, old, pregnant, and immunocompromised. Here, we present the genome sequence of L. monocytogenes H34, a serotype 1/2b, lineage I, sequence type 489 (ST489) strain, isolated from a neonatal sepsis case in Uruguay.

[A five-year experience with zoonotic Salmonella at a pediatric reference centre]. / Un quinquenio de experiencia (2005-2010) con infecciones por Salmonella spp en un centro nacional de referencia en pediatría.

BACKGROUND: Salmonella can cause asymptomatic infections, diarrhea, bacteremia and focal infections such as meningitis and osteomyelitis. AIM: To describe clinical and microbiological aspects of infections by Salmonella spp. in children in a pediatric referral hospital: Centro Hospitalario Pereira Rossell, in Montevideo, Uruguay. MATERIALS AND METHODS: Descriptive and retrospective study of 46 patients, from which Salmonella spp was isolated between January 1, 2005 and December 31, 2010. RESULTS: Salmonella spp was isolated in 46 children younger than 15 years old. 18 were below 2 years old and 5 children below three months. 24% of the children had risk factors, such as HIV infection, oncological diseases and malnutrition; low birth weight and pneumonia were associated conditions. No deaths were reported. The serotypes more frequently found were: Typhimurium and Enteritidis. Most of the strains were susceptible to ampicillin and third generation of cephalosporins. DISCUSSION: Diarrhea with blood was the predominant clinical presentation, and there were no outbreaks. Typhimurium and Enteritidis were the most common serotypes. Based on the profiles of susceptibility antimicrobial, we could maintain the same recommendations until the moment suggested. CONCLUSIONS: we must consider the Salmonella infection in febrile children under risk of an invasive bacterial disease, with or without focal infection.

Pneumococcal Meningitis Before and After Universal Vaccination With Pneumococcal Conjugate Vaccines 7/13, Impact on Pediatric Hospitalization in Public and Nonpublic Institutions, in Uruguay.

This is the first study showing the impact of 13-valent pneumococcal conjugate vaccine on pneumococcal meningitis in Latin America; a significant (63.5%) reduction in hospitalization was observed during the first 6 years after starting vaccination. A 90% reduction of pneumococcal conjugate vaccines 7/13 serotypes was observed (P < 0.0001). After vaccination, all strains were penicillin susceptible. Mortality had a reduction of 71%.

Phenotypic and genotypic characterization of oxacillin-susceptible and mecA positive Staphylococcus aureus strains isolated in Uruguay / Caracterización fenotípica y genotípica de cepas de Staphylococcus aureus sensibles a oxacilina y mecA positivas aisladas en Uruguay

Abstract The aim of this study was to characterize phenotypically and genotypically 27 mecApositive Staphylococcus aureus strains with oxacillin MICs of ≤2 g/ml by Vitek 2, isolated indifferent regions of Uruguay. Susceptibility to oxacillin and cefoxitin was studied by gradient dif-fusion, disk diffusion to cefoxitin, and Phoenix and MicroScan systems. PBP2a was determined.SCCmec typing was performed and the isolates were compared by PFGE. Twenty-six isolateswere susceptible to oxacillin; one strain was susceptible to cefoxitin by disk diffusion and 3strains by gradient diffusion. Phoenix and MicroScan panels detected methicillin resistance in25 and 27 strains, respectively. Twenty-six strains tested positive for PBP2a. Twenty-six strainscarried SCCmec V and 24 belonged to pulsotype A. One strain carried SCCmec IV and did notbelong to pulsotype A. Cefoxitin disk diffusion test and PBP2a detection correctly identified 26of these 27 strains as MRSA. PFGE results suggest the dissemination of a cluster of MRSA carryingSCCmec V.

Resumen El objetivo de este estudio fue caracterizar fenotípicamente y genotípicamente 27 cepas de Staphylococcus aureus positivas para mecA y con CIM de oxacilina <2 pg/ml según Vitek 2, obtenidas en diferentes regiones del país. La sensibilidad frente a la oxacilina y la cefoxitina se estudió por difusión en gradiente, por disco-difusión (cefoxitina) y por los sistemas Phoenix y MicroScan. Se analizó la portación de PBP2a, se realizó la tipificación de SCCmec y las cepas se compararon mediante PFGE. Resultaron sensibles a oxacilina por difusión en gradiente 26 cepas; una fue sensible a cefoxitina por disco-difusión y 3 lo fueron por difusión en gradiente. Los sistemas Phoenix y MicroScan detectaron resistencia a meticilina en 25 y 27 cepas, respectivamente. Asimismo, 26 cepas portaban PBP2a y 26 cepas mostraron presencia de SCCmec V, 24 correspondieron al pulsotipo A. Una portaba SCCmec IV y no perteneció al pulsotipo A. La prueba de disco-difusión con cefoxitina y la detección de PBP2a identificaron 26 de 27 cepas como MRSA. La PFGE sugiere la diseminación de un grupo MRSA con SCCmec V. © 2022 Asociación Argentina de Microbiología. Publicado por Elsevier Espana, S.L.U. Este es un artículo Open Access bajo la licencia CC BY-NC-ND (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Utilidad del panel FilmArray® BCID en la detección de bacteriemia: estudio multicéntrico latinoamericano / Usefulness of the FilmArray® BCID panel in the detection of bacteremia: Latin American multicenter study

Resumen Los objetivos de este estudio fueron determinar el desempeño del panel BCID de FilmArray® y establecer el impacto de estos resultados en el tratamiento antimicrobiano de pacientes con bacteriemia en 11 hospitales de Latinoamérica. Se incluyeron 397 episodios de bacteriemia y se documentaron 551 microorganismos aislados de hemocultivos. La identificación microbiana fue correcta en el 91,4% (504/551) de los aislados y en el 98,6% (504/511) si se consideran solo los microorganismos incluidos en el panel BCID. La sensibilidad en la detección de los genes mecA, vanA/B y blaKPC fue del 100% y la especificidad fue del 97%, 100% y 99,6% respectivamente. La notificación temprana del resultado permitió cambios terapéuticos en 242 episodios (60,9%). El panel BCID es un método confiable y rápido para la detección de mecanismos críticos de resistencia y de los microorganismos más frecuentemente aislados de bacteriemias y permite la optimización temprana del tratamiento antimicrobiano.

Abstract The objectives of this study were to determine the performance of the BCID panel and to establish the impact of these results on the antimicrobial treatment of patients with bacteremia in 11 hospitals in Latin America. Three hundred and ninety-seven episodes of bacteremia were included and 551 microorganisms isolated from blood cultures were documented. Microbial identification was correct in 91.4% (504/551) of the isolates and in 98.6% (504/511) if only the microorganisms included in the BCID panel are considered. The sensitivity in the detection of the genes mecA, vanA/B and blaKPC was 100% and the specificity was 97%, 100% and 99.6% respectively. Early notification of the outcome allowed therapeutic changes in 242 episodes (60.9%). The BCID panel is a reliable and rapid method for the detection of critical resistance mechanisms and of the microorganisms most frequently isolated from bacteremia and it enables early optimisation of antimicrobial treatment.

Resumo Os objetivos deste estudo foram determinar o desempenho do painel BCID do FilmArray® e estabelecer o impacto desses resultados no tratamento antimicrobiano de pacientes com bacteremia em 11 hospitais da América Latina. Trezentos e noventa e sete episódios de bacteremia foram incluídos e 551 microrganismos isolados de hemoculturas foram documentados. A identificação microbiana foi correta em 91,4% (504/551) dos isolados e em 98,6% (504/511) considerando apenas os microrganismos incluídos no painel BCID. A sensibilidade na detecção dos genes mecA, vanA/B e blaKPC foi de 100% e a especificidade foi de 97%, 100% e 99,6% respectivamente. A notificação precoce do desfecho permitiu mudanças terapêuticas em 242 episódios (60,9%). O painel BCID é um método confiável e rápido para a detecção de mecanismos críticos de resistência e dos microrganismos mais frequentemente isolados da bacteremia e permite a otimização precoce do tratamento antimicrobiano.