Dominance of ST131, B2, blaCTX-M-15, and papA-papC-kpsMII-uitA among ESBL Escherichia coli isolated from bloodstream infections in Quito, Ecuador: a 10-year surveillance study (2009-2019).

AIMS: This study aimed to examine antibiotic resistance and the epidemiology of extended-spectrum ß-lactamases (ESBL)-producing Escherichia coli associated with bloodstream infections over a period of 10 years. METHODS AND RESULTS: Isolates were collected from January 2009 to December 2019 and those testing for E. coli were included. Antibiotic susceptibility was tested using the VITEK® system. Selected isolates were further characterized by amplification of marker genes (virulence traits, phylogroups, and sequence types). A total of 166 ESBL-producing E. coli were recovered. The blaCTX-M-15 allele was the most abundant. Most of the isolates were resistant to ceftriaxone, cefepime, ceftazidime, ampicillin/sulbactam, piperacillin/tazobactam, and ciprofloxacin. No resistance to carbapenems was registered. More than 80% of bacteria were classified as extraintestinal pathogenic E. coli (ExPEC), and the combination of virulence traits:papA-papC-kpsMII-uitA was the most common. Phylogroup B2 was the most prevalent, and bacteria predominantly belonged to ST131. CONCLUSIONS: There was an increase in the ExPEC ESBL-E coli in bloodstream infections and the relationship between the isolates found in these infections during these 10 years.

Diseminación clonal de KPC-2 en Klebsiella pneumoniae resistente a carbapenémicos / Clonal dissemination of KPC-2 in carbapenem resistant Klebsiella pneumoniae

Objetivo: Determinar los mecanismos de resistencia antibiótica y la epidemiología molecular de aislados clínicos de Klebsiella pneumoniae resistentes a carbapenémicos. Materiales y métodos: 30 aislados multirresistentes de K. pneumoniae fueron obtenidos a partir de: urocultivo, aspirado traqueal, secreción de herida, sonda vesical, hemocultivo, líquido peritoneal, punta de catéter, colección abdominal y secreción bronquial. Los aislados fueron colectados de noviembre de 2012 a abril de 2013. La identificación y susceptibilidad antibiótica fue determinada por el sistema automatizado VITEK 2. Para la amplificación de genes de resistencia se empleó PCR, la determinación de las Secuencias Tipo (ST) fue obtenida por tipificación multilocus de secuencias (MLST) y la relación clonal fue establecida por electroforesis en gel de campo pulsado (PFGE). Resultados: Todos los aislados mostraron fenotipos multirresistentes, excepto a colistina y tigeciclina. El 100% de los aislados fue productor de la carbapenemasa KPC-2. La determinación de la presencia de genes codificantes de β-lactamasas de Espectro Extendido mostró que el 67% de los aislados fue positivo para el gen blaCTX-M, el 100% fue positivo para el gen blaSHV y 93% fue positivo para el gen blaTEM. El análisis de la relación clonal de los 30 aislados agrupó a 20 en un mismo pulso tipo. El análisis por MLST demostró que la ST predominante fue ST258 presente en el 60% de la población, seguida de ST1199 presente en el 20% de la población analizada. Conclusiones: Los resultados obtenidos demuestran la importancia de implementar y combinar estudios epidemiológicos, clínicos y moleculares para comprender la distribución de la resistencia entre bacterias de interés clínico.

Objective: To determine the mechanism of antibiotic resistance and molecular epidemiology of carbapenem resistant isolates of Klebsiella pneumoniae. Materials and Methods: 30 multidrug resistant isolates of K. pneumoniae were obtained from urine culture, tracheal aspirate, wound secretion, bladder catheter, blood culture, peritoneal fluid, catheter tip, abdominal collection, and bronchial secretion. K. pneumoniae isolates were collected between November 2012 and April 2013. Identification and susceptibility were determined by the VITEK 2 system. Resistance genes were identified by PCR, sequence type (ST) was established by multilocus sequence typing (MLST), and clonal relationship was defined by pulsed field gel electrophoresis (PFGE). Results: All isolates were multidrug resistant and susceptible to colistin and tigecycline. 100% of isolates produced KPC-2 carbapenemase. This study detected Extended Spectrum β-Lactamases enconding genes. 67% of isolates were positive for blaCTX-M, 100% were positive for blaSHV, and 93% of isolates were positive for blaTEM. Analysis of the clonal relationship clustered 20 isolates in the same clonal complex. Multilocus sequence typing showed the predominant sequence type ST 258 in 60% of population. ST 1199 were present in 20% of bacterial population. Conclusion: Molecular epidemiology, clinical research and molecular biology studies improve understanding of mechanisms of resistance distribution among bacteria of clinical interest.

Ciprofloxacin susceptibility reduction of salmonella strains isolated from outbreaks

The antimicrobial susceptibility of 212 Salmonella strains isolated from patients and foods was evaluated and 45 percent were found to be resistant to nalidixic acid. Nalidixic acid resistant strains showed a higher minimal inhibitory concentration for ciprofloxacin than sensitive strains. During the study an increase of strains with reduced susceptibility to ciprofloxacin was also observed.

Ciprofloxacin susceptibility reduction of Salmonella strains isolated from outbreaks.

The antimicrobial susceptibility of 212 Salmonella strains isolated from patients and foods was evaluated and 45% were found to be resistant to nalidixic acid. Nalidixic acid resistant strains showed a higher minimal inhibitory concentration for ciprofloxacin than sensitive strains. During the study an increase of strains with reduced susceptibility to ciprofloxacin was also observed.

Avaliação epidemiológica de surtos de salmonelose ocorridos no período de 1999 a 2008 no Estado do Paraná, Brasil / Epidemiological data of salmonellosis outbreaks occured between 1999 and 2008 in Parana State, Brazil

No Paraná, são poucas as informações sobre a prevalência dos sorovares e fagotipos de Salmonella envolvidos em surtos. Este trabalho foi realizado com o objetivo de conhecer o perfil epidemiológico dos surtos de salmonelose notificados no Estado do Paraná entre janeiro de 1999 e dezembro de 2008. Neste período ocorreram 286 surtos nos quais 5.641 pessoas foram expostas, 2.027 (35,9%) manifestaram sintomas da doença e 881 (16,3%) foram hospitalizadas. Cinquenta e dois municípios do Paraná (13,0%) notificaram surtos de salmonelose. Alimentos à base de ovos, carnes e derivados e produtos classificados como alimentos variados foram, respectivamente, associados a 45,0; 34,8 e 20,2% dos surtos. O sorovar prevalente foi Enteritidis, encontrado em 87,8% das cepas isoladas de pacientes e em 80,6% das cepas provenientes dos alimentos envolvidos nos surtos. Salmonella Enteritidis PT4 foi o fagotipo predominante, porém foi observada maior prevalência de PT9 a partir de 2003. Do total de surtos analisados, 49,7% estiveram associados a reuniões familiares. Esse fato sugere que as ações da Vigilância Sanitária devem assumir um caráter educativo, tanto para trabalhadores de estabelecimentos comerciais quanto para manipuladores domésticos.

Epidemiological data of foodborne diseases in Brazil are scarce. In Paraná State, there is little information on the prevalence of Salmonella serovars and fagotypes involved in outbreaks. The aim of this study was to evaluate epidemiological data of salmonellosis outbreaks notified in Paraná State between January 1999 and December 2008. During the study period, 286 Salmonella outbreaks occurred and a total of 5,641 people were exposed, 2,027 (35.9%) became ill, and 881 (16.3%) were hospitalized. Fifty-two cities (13.0%) in Paraná notified Salmonella outbreaks. Eggs and egg products, meat and meat products and other foods were, respectively, associated with 45.0, 34.8 and 20.2% of the notified outbreaks. Serovar Enteritidis was prevalent and identified in 87.8% of the strains isolated from patients and in 80.6% of the strains isolated from food involved in outbreaks. Salmonella Enteritidis PT4 was the prevalent phagotype. However, a prevalence of PT9 occurred after 2003. Of the total number of outbreaks analyzed, 49.7% occurred in residences. This result indicates that educational actions of the State Food Safety and Inspection Service should be for both commercial and domestic food handlers.

Produção e purificação de anticorpos policlonais para Salmonella Enteritidis (Enterobacteriaceae) / Production and purification of polyclonal antibodies for Salmonella Enteritidis (Enterobacteriaceae)

O objetivo deste trabalho foi produzir e purificar anticorpos policlonais específicos para Salmonella Enteritidis (Enterobacteriaceae). O anti-soro foi produzido em coelhos, empregando-se flagelina purificada. O título e a especificidade foram determinados através do ensaio imunoenzimático - ELISA e a purificação por cromatografia de afinidade com sepharose Proteína A. As suspensões bacterianas foram cultivadas em cinco diferentes meios de cultura (infusão de cérebro coração - BHI, caldo tripticase soja, caldo lactosado, caldo nutriente - CN e água peptonada). Observou-se que dependendo do meio o título do anti-soro pode variar e os melhores resultados foram obtidos com BHI e CN. O anti-soro foi específico para Salmonella Enteritidis, apresentando porcentagens de reações cruzadas com Salmonella Typhimurium, Salmonella Infantis e Salmonella Newport de 16,0, 11,9 e 6,4 por cento, respectivamente. Menores porcentagens foram obtidas com outras enterobactérias testadas. Esses resultados indicam a possibilidade da utilização desses anticorpos na padronização de ensaios imunológicos para a detecção de Salmonella Enteritidis

Urea is Necessary for the Culture of Embryos of the Marsupial Frog Gastrotheca riobambae, and is Tolerated by Embryos of the Aquatic Frog Xenopus laevis: (ureotelism/urea concentration in frog blood/culture of frog embryos/mesoderm induction).

Urea was found in the capsular fluid that bathes Gastrotheca riobambae embryos during incubation in the maternal pouch. The urea concentration in this fluid is higher than in blood from the mother, indicating that urea is accumulated by the embryo during the period of maternal incubation. Gastrotheca tadpoles tolerate up to 500 mM urea with 86% survival after 24 hours and die in solutions of 0.5 mM ammonia. These findings suggest that urea plays a role in the adaptation of G. riobambae embryos to the conditions of water stress within the maternal pouch. To improve the in vitro culture conditions of early embryos taken from the maternal pouch, a saline solution that contains urea was designed (GRS). GRS plus 30 mM urea was used for the culture of cleavage to the neurula stage embryos of G. riobambae. During organogenesis, the urea concentration was raised to 60 mM. Early embryos of Xenopus laevis tolerate urea, and in addition, no inducing effects of urea have been detected in animal cap explants of Xenopus.