Cutaneous infection by non-diphtheria-toxin producing and penicillin-resistant Corynebacterium diphtheriae strain in a patient with diabetes mellitus.

Diphtheria is a potentially fatal infection, mostly caused by diphtheria toxin (DT)-producing Corynebacterium diphtheriae strains. During the last decades, the isolation of DT-producing C. diphtheriae strains has been decreasing worldwide. However, non-DT-producing C. diphtheriae strains emerged as causative agents of cutaneous and invasive infections. Although endemic in countries with warm climates, cutaneous diphtheria is rarely reported in Brazil. Presently, an unusual case of skin lesion in a Brazilian elderly diabetic patient infected by a penicillin-resistant non-DT-producing C. diphtheriae strain was reported. Laboratory diagnosis included mass spectrometry and multiplex PCR analyses. Since cutaneous diphtheria lesions are possible sources of secondary diphtheria cases and systemic diseases and considering that penicillin is the first line of antimicrobial agent for the treatment of these infections, the detection of penicillin-resistant strains of diphtheria bacilli should be a matter of concern. Thus, cases similar to the presently reported should be appropriately investigated and treated, particularly in patients with risk factor (s) for the development of C. diphtheriae invasive infections, such as diabetes. Moreover, health professionals must be aware of the presence of C. diphtheriae in cutaneous lesions of lower limbs, a common type of morbidity in diabetic patients, especially in tropical and subtropical countries.

Frecuencia y susceptibilidad a penicilina y meticilina de aislamientos ambientales de Staphylococcus aureus en un hospital de Cuenca / Frequency and susceptibility to penicillin and methicillin of Staphylococcus aureus environmental isolations at a Cuenca´s hospital

Staphylococcus aureus es un patógeno asociado con infecciones intrahospitalarias comúnmente hallado en las fosas nasales y las manos del personal de salud; así como, en superficies ambientales, las cuales se convierten en potenciales reservorios y vehículos de transmisión de infecciones. En este estudio se analizó la frecuencia y la susceptibilidad a penicilina y meticilina de aislamientos ambientales de S. aureus en un hospital de Cuenca. Se recolectaron 50 muestras (30 de dos quirófanos y 20 de la sala de cuidados intensivos). S. aureus se identificó por pruebas fenotípicas y detección molecular del gen nuc. La susceptibilidad a meticilina y penicilina se determinó por el método de difusión del disco en agar y los genes blaZ y mecA por reacción en cadena de la polimerasa. La frecuencia de S. aureus fue de 6% (3/50 cepas). La resistencia a penicilina y meticilina fue de 66,6% (2/3 cepas). Los genes blaZ y mecA se detectaron en las dos cepas resistentes a penicilina y meticilina. La baja frecuencia de S. aureus puede estar relacionada con los ambientes analizados; ya que, las superficies muestreadas son áreas donde se hace énfasis en la aplicación de protocolos de higiene y desinfección para asegurar una adecuada descontaminación

Staphylococcus aureus is a pathogen associated with intrahospital infections commonly found in the nasal cavities and the hands of health personnel, as well as, on environmental surfaces; which become potential reservoirs and transmission vehicles of infections. In this study the frequency and susceptibility to penicillin and methicillin of environmental isolates of S. aureus in a hospital to Cuenca were analyzed. 50 samples (30 of two operating room and 20 of the intensive care room) were collected. S. aureus was identified by phenotypic tests and molecular detection of the nuc gene. The susceptibility to methicillin and penicillin was determined by agar disc diffusion method and the blaZ and mecA genes by polymerase chain reaction. The frequency of S. aureus was 6% (3/50 strains). Resistance to penicillin and methicillin was 66.6% (2/3 strains). The blaZ and mecA genes were detected in the two strains resistant to penicillin and methicillin. The low frequency of S. aureus may be related to the environments analyzed; because the surfaces sampled are areas where emphasis is placed on the application of hygiene and disinfection protocols for ensure adequate decontamination

High Prevalence of the aac(6')-Ie-aph(2'')-Ia Gene in Hospital Isolates of Enterococcus faecalis Co-Resistant to Gentamicin and Penicillin.

Objectives: This study aimed to characterize the molecular mechanism of resistance to gentamicin among penicillin-resistant, ampicillin-susceptible Enterococcus faecalis (PRASEF) isolates by investigating the presence of the aac(6')-Ie-aph(2'')-Ia gene. The co-resistance to antimicrobials of other classes was also evaluated. Results: Among the 151 isolates evaluated, 70 were PRASEF and 81 were penicillin-susceptible and ampicillin-susceptible E. faecalis (PSASEF). No ß-lactamase producing isolate was detected. Eighty-three (55.0%) and 35 (23.2%) out of the 151 E. faecalis isolates showed high-level gentamicin resistance (HLGR) and high-level streptomycin resistance (HLSR) phenotypes. However, a significantly higher rate of PRASEF (88.6%) showed HLGR phenotype in comparison with PSASEF (23.5%) (p < 0.01). Conversely, a significantly lower rate of PRASEF (14.3%) showing HLSR was observed in comparison with PSASEF (30.9%) (p = 0.02). The prevalence of isolates displaying multidrug resistance (MDR) phenotype was significantly higher (p < 0.01) in the group of PRASEF (81.4%) than in PSASEF (18.6%). The majority of PSASEF (61.9%) and PRASEF (90.3%) isolates showing HLGR phenotype was harboring the aac(6')-Ie-aph(2'')-Ia gene, which encodes a bifunctional enzyme that inactivates all aminoglycosides except streptomycin. Conclusion: The aac(6')-Ie-aph(2'')-Ia gene was prevalent among the Brazilian PRASEF isolates that usually exhibit co-resistance to gentamicin and to multiple other drugs.

Evaluation of polymorphisms in pbp4 gene and genetic diversity in penicillin-resistant, ampicillin-susceptible Enterococcus faecalis from hospitals in different states in Brazil.

The aim of the present study was to verify whether penicillin-resistant, ampicillin-susceptible Enterococcus faecalis (PRASEF) occurred in Brazil prior to the beginning of the 21st century, and to verify whether ampicillin susceptibility can predict susceptibility to other ß-lactams in E. faecalis with this inconsistent phenotype. The presence of polymorphisms in the pbp4 gene and genetic diversity among the isolates were investigated. Of 21 PRASEF analyzed, 5 (23.8%) and 4 (19.0%) were imipenem and piperacillin resistant simultaneously by disk diffusion and broth dilution respectively, contradicting the current internationally accepted standards of susceptibility testing. Sequencing of pbp4 gene revealed an amino acid substitution (Asp-573→Glu) in all PRASEF isolates but not in the penicillin-susceptible, ampicillin-susceptible E. faecalis. Most PRASEF (90.5%) had related pulsed-field gel electrophoresis profiles, but were different from other PRASEF described to date. Results demonstrate that penicillin-resistant, ampicillin-susceptible phenotype was already a reality in the 1990s in E. faecalis isolates in different Brazilian states, and some of these isolates were also imipenem- and piperacillin-resistant; therefore, internationally accepted susceptibility criteria cannot be applied to these isolates. According to pbp4 gene sequencing, this study suggests that a specific amino acid substitution in pbp4 gene found in all PRASEF analyzed is associated with penicillin resistance.

Comparison of phenotypic tests for detecting penicillin G resistance with presence of blaZ gene in Staphylococcus aureus isolated from bovine intramammary infections.

Few studies have described the relationship between genotypic and phenotypic methods for detecting penicillin resistance in Staphylococcus aureus isolated from bovine intramammary infection (IMI). Six phenotypic methods for penicillinase detection were compared with a genotypic method testing the presence of the ß-lactamase gene blaZ in Staph. aureus (n = 150) isolated from bovine IMI. Highest sensitivities and specificities were observed for disk diffusion (DD) (93 and 97.4%), minimum inhibitory concentration (MIC) (90.3 and 97.4%), Cefinase™ (85.9 and 97.4%) and Diatabs™ (85.7 and 98.7%). The estimated cut-off points estimated in the present study can be considered close to the ones indicated by CLSI (2013). The molecular detection of blaZ gene is the only method that may indicate the real or potential capacity of producing ß-lactamase in Staph. aureus. Considering that from a clinical standpoint a false negative result from a phenotypic test is the most unfavourable situation, a combination of standard DD with Diatabs™ or Cefinase™ should be performed by routine mastitis laboratories to minimise false negative results.

Penicillin-resistant, ampicillin-susceptible Enterococcus faecalis of hospital origin: pbp4 gene polymorphism and genetic diversity.

Despite the spread of penicillin-resistant, ampicillin-susceptible Enterococcus faecalis (PRASEF) isolates in diverse countries, the mechanisms leading to this unusual resistance phenotype have not yet been investigated. The aim of this study was to evaluate whether polymorphism in the pbp4 gene is associated with penicillin resistance in PRASEF isolates and to determine their genetic diversity. E. faecalis isolates were recovered from different clinical specimens of hospitalized patients from February 2006 to June 2010. The ß-lactam minimal inhibitory concentrations (MICs) were determined by E-test®. The PCR-amplified pbp4 gene was sequenced with an automated sequencer. The genetic diversities of the isolates were established by PFGE (pulsed-field gel electrophoresis) and MLST (multilocus sequencing typing). Seventeen non-producing ß-lactamase PRASEF and 10 penicillin-susceptible, ampicillin-susceptible E. faecalis (PSASEF) strains were analyzed. A single-amino-acid substitution (Asp-573→Glu) in the penicillin-binding domain was significantly found in all PRASEF isolates by sequencing of the pbp4 gene but not in the penicillin-susceptible isolates. In contrast to the PSASEF isolates, a majority of the PRASEFs had similar PFGE profiles. Six representative PRASEF isolates were resolved by MLST into ST9 and ST524 and belong to the globally dispersed clonal complex 9 (CC9). In conclusion, it appears quite likely that the amino acid alteration (Asp-573→Glu) found in the PBP4 of the Brazilian PRASEF isolates may account for their reduced susceptibility to penicillin, although other resistance mechanisms remain to be investigated.

Spatial exploration of Streptococcus pneumoniae clonal clustering in São Paulo, Brazil

OBJECTIVES: To examine the spatial distribution of Streptococcus pneumoniae and its clonal patterns collected between 2002 and 2006 in São Paulo, Brazil. METHODS: As part of an observational study in São Paulo city, Brazil, S. pneumoniae isolates routinely cultured from blood, respiratory specimens, or cerebrospinal and other profound fluids were selected. Additionally, only isolates with either penicillin (PEN) intermediate (I) or resistant (R) status on routine antibiogram were included, in order to obtain a higher probability of clonal isolates. A single I/R S. pneumoniae isolate per patient was included and submitted to genotypic determination by pulsed field gel electrophoresis (PFGE). Minimum inhibitory concentrations (MICs) were determined for the isolates by Etest® to PEN and other antimicrobials. Each isolate was geocoded in a digital map. The Kernel function and ratio methods between total isolates vs. clones were used in order to explore possible cluster formations. RESULTS: Seventy-eight (78) S. pneumoniae community isolates from two major outpatient centers in São Paulo, Brazil, were selected from the databank according to their penicillin susceptibility profile, i.e. R or I to penicillin assessed by oxacillin disc diffusion. Of these, 69 were submitted to PFGE, 65 to MIC determination, and 48 to spatial analytical procedures. Preliminary spatial analysis method showed two possible cluster formation located in southwest and southeast regions of the city. CONCLUSION: Further analyses are required for precisely determining the existence of S. pneumoniae clusters and their related risk factors. Apparently there is a specific transmission pattern of S. pneumoniae clones within certain regions and populations. GIS and spatial methods can be applied to better understand epidemiological patterns and to identify target areas for public health interventions.

Alta prevalência de crianças portadoras de Streptococcus pneumoniae resistentes à penicilina em creches públicas / High prevalence of children colonized with penicillin-resistant Streptococcus pneumoniae in public day-care centers

OBJETIVOS: Investigar a prevalência de Streptococcus pneumoniae (pneumococos) na nasofaringe de crianças sadias atendidas em creches municipais da cidade de Umuarama (PR). Avaliar a susceptibilidade aos antimicrobianos dos pneumococos isolados. MÉTODOS: Secreção da nasofaringe de 212 crianças foi coletada no período de abril a outubro de 2008. Após semeadura dos espécimes em ágar sangue e incubação a 37 °C por 24-48 horas, as colônias suspeitas de pertencerem a S. pneumoniae foram identificadas pela α-hemólise, sensibilidade à optoquina e bile solubilidade. A susceptibilidade à penicilina foi investigada pelos testes de disco-difusão e de diluição. A susceptibilidade aos demais antimicrobianos indicados no tratamento das infecções pneumocócicas foi realizada por disco-difusão RESULTADOS: A prevalência de pneumococos na nasofaringe foi de 43,4 por cento (92/212), sendo maior em crianças com idade entre 2 e 5 anos (p = 0,0005). Não houve diferença significativa entre os sexos. Resistência intermediária e resistência plena à penicilina foram encontradas respectivamente em 34,8 (32/92) e 22,8 por cento (21/92) dos isolados. Sessenta e sete amostras (72,8 por cento) foram resistentes ao sulfametoxazol-trimetoprim, oito (8,7 por cento) à eritromicina e seis (6,5 por cento) à tetraciclina. Uma amostra apresentou resistência à clindamicina (1,1 por cento), e outra ao cloranfenicol (1,1 por cento). Todas as amostras foram sensíveis a levofloxacina, ofloxacina, rifampicina, telitromicina, linezolide e vancomicina. Nove amostras foram consideradas multirresistentes, por apresentarem resistência a três ou mais classes de antimicrobianos. CONCLUSÕES: O presente estudo registrou uma alta prevalência de crianças portadoras sadias de amostras de S. pneumoniae resistentes à penicilina que podem constituir importantes reservatórios desse patógeno na comunidade.

OBJECTIVES: To investigate the prevalence of Streptococcus pneumoniae (pneumococci) in the nasopharynx of healthy children enrolled in public day-care centers of the municipality of Umuarama, state of Paraná, Brazil. The susceptibility of the pneumococcal strains to antimicrobial agents was also studied. METHODS: Nasopharyngeal specimens from 212 children were collected from April to October 2008. After the specimens were seeded in blood agar and incubated at 37 °C for 24-48 hours, the colonies suspected of belonging to S. pneumoniae were identified using α-hemolysis, optochin sensitivity, and bile solubility test. Penicillin susceptibility was investigated using the disk diffusion and dilution tests. Susceptibility to the other antimicrobial agents indicated for the treatment of pneumococcal infections was investigated using the disk diffusion test. RESULTS: The prevalence of nasopharyngeal pneumococci was 43.4 percent (92/212), with higher rates in children between 2 and 5 years old (p = 0.0005). There was no significant difference between sexes. Intermediate and full resistance to penicillin were found in 34.8 (32/92) and 22.8 percent (21/92) isolates, respectively. Sixty-seven strains (72.8 percent) were resistant to sulfamethoxazole-trimethoprim, eight (8.7 percent) were resistant to erythromycin, and six (6.5 percent) to tetracycline. One strain was resistant to clindamycin (1.1 percent) and another was resistant to chloramphenicol (1.1 percent). All strains were sensitive to levofloxacin, ofloxacin, rifampicin, telithromycin, linezolid, and vancomycin. Nine strains were considered multiresistant because they were resistant to three or more classes of antimicrobial agents. CONCLUSIONS: The present study detected a high prevalence of healthy children colonized with penicillin-resistant S. pneumoniae strains who may be important reservoirs of this pathogen in the community.

Distribución de serotipos y patrón de sensibilidad in vitro a diferentes antibióticos de cepas de Streptococcus pneumoniae obtenidas de niños menores de 15 años en aislamientos invasores en el departamento de Risaralda, 1999 a 2004 / Serotype Distribution and in Vitro Antibiotic Sensitivity of Streptococcuspneumoniae Strains from Invasive Disease Isolates among Children Under 15Years Old, in Risaralda, Colombia, 1999 to 2004

Objetivo. Identificar las cepas prevalecientes de Streptococcus pneumoniae causantes de enfermedad invasiva y su patrón de sensibilidad a la penicilina en niños menores de 15 años que habitan el departamento de Risaralda. Método. Análisis descriptivo a partir de muestras de fluidos estériles analizados por el Instituto Nacional de Salud dentro de su programa de vigilancia epidemiológica del neumococo, y provenientes de niños menores de 15 años del departamento de Risaralda durante los años 1999 a 2004. Resultados. Las cepas prevalentes de S. pneumoniae en Risaralda no son diferentes a las halladas en otras regiones del país. La tasa de resistencia del neumococo aislado en fluidos estériles por ciento - 26,2 por ciento). Para menores de 5 años fue de 35 por ciento. No hay datos de sensibilidad a las cefalosporinas de tercera generación. Conclusión. La implementación de un programa de vacunación contra neumococo en el departamento del Risaralda prevendría en un alto porcentaje la posibilidad de adquirir enfermedad invasiva. Dado el alto índice de resistencia a la penicilina, los esquemas antibióticos empíricos para enfermedad invasiva por neumococo en menores de 5 años deben incluir la vancomicina y las cefalosporinas de tercera generación hasta que se obtengan cultivos definitivos

AbstarctObjective: To identify the most prevalent sero-types and in vitro antimicrobial susceptibility topenicillin and other antibiotics in children under 15years old who have Streptococcus pneumoniaeinvasive disease and live in the department ofRisaralda (Colombia). Method: We reviewed thedata analyzed by the Instituto Nacional de Saludfrom S. pneumoniae sterile fluid's isolated during5 years (1999 to 2004). Results: Most prevalentserotypes of S. pneumoniae in Risaralda are notdifferent from others departments of Colombia. Itsresistance to penicillin was 22% for all childrenand 35% for children under 5 years old. 7.5% ofthe isolates had intermediated sensitivity toceftriaxone. Conclusions: An immunization pro-gram in children under 5 years old in Risaraldawould prevent a lot of cases of invasive disease byS. pneumoniae. The empiric treatment of S. pneu-moniae Invasive Disease in children under 5 yearsold in Risaralda would include vancomycin plus athird generation cephalosporins until antibiogramis developed

Estafilococos y enterococos: ¿amenazas a la salud pública?: epidemiología y mecanismos de resistencia a los antibióticos / Staphylococci and enterococci: threats to public health?: epidemiology and mechanisms of resistance to antibiotics

La resistencia a los antimicrobianos se está convirtiendo en un problema de salud emergente. Las especies de estafilococos y enterococos son microorganismos causantes de múltiples y frecuentes infecciones en el ser humano, principalmente a nivel nosocomial. El Staphylococcus aureus ha adquirido mecanismos de resistencia a la penicilina, a las penicilinas resistentes a las penicilinasas -meticilina- (SAMR), y recientemente, a la vancomicina (VISA). El enterococo es intrínsecamente resistente a gran variedad de agentes antimicrobianos y ha adquirido resistencia a betalactámicos, aminoglicósidos y glicopéptidos. Múltiples mecanismos explican la adquisición, desarrollo y diseminación de la resistencia. Existen en el momento pocas alternativas para tratar infecciones producidas por microorganismos resistentes y las medidas en el momento se deben dirigir al control del uso de antibióticos y prevención de la diseminación. Se realiza una revisión de la epidemiología, mecanismos de resistencia, opciones de tratamiento y medidas de control de estos microorganismos.

Antimicrobial resistance is becoming an emerging health problem. Gram-positive cocci are bacterias which cause multiple and frequent infections in the human being, specially nosocomialleveL Staphylococcus aureus has acquired resistance mechanisms to penicillins,methicillin (MRSA) and recently to vancomycin (VISA). Enteroccocus spp is intrincically resistant to a great variety of antimicrobial agents and it has acquired resistance to betalactamics, aminoglycosides and glycopeptides. Multiple mechanisms explain theacdquisition, development and spread of resistance. At the moment there are a few alternatives to treat infections produced by resistant bacterias and the measurements should be directed to the control in the antibiotics use and infection control practice. This reviewattempts to point out the edpidemiology, resistance mechanisms treatment options and prevention means of these microorganisms.

Estafilococos multirresistentes: uso del disco de oxacillín como marcador de resistencia a antibióticos

Se estudió la susceptibilidad in vitro de cepas pertenecientes al género Staphylococcus frente a diferentes antibióticos y se hizo énfasis en la vancomicina y la penicilina a partir del grado de resistencia presentado frente al oxacillín. Se utilizaron 200 cepas de estafilococos, 100 de ellas pertenecientes a la especie Staphylococcus aureus y otras 100 a estafilococos coagulasa negativos. El origen de las cepas fue tanto intrahospitalario como comunitario. Se observó resistencia notable al oxacillín, altísima frente a la penicilina e incipiente a la vancomicina por parte de las cepas estudiadas, sobre todo en estafilococos coagulasa negativos. Las cepas oxacillín-resistentes mostraron los valores más altos y un amplio espectro de resistencia a los antibióticos.

The susceptibility in vitro of strains belonging to the genus Staphylococcus was studied by using different antibiotics. Emphasis was made on vancomycin and penicillin based on the degree of resistance to oxacillin. 200 strains of staphylococci were used. l00 of them belonging to the Staphylococcus aureus species and the other 100 to coagulase-negative staphylococci. The strains had an intrahospital and community origin. The rates of resistance observed among the studied strains, mainly the coagulase-negative staphylococci, were as follows: significant to oxacillin, very high to penicillin and incipient to vancomycin. The oxacillin-resistant strains showed the highest values and a wide spectrum of resistance to antibiotics.