Objectives To evaluate the usefulness of real-time polymerase chain reaction (RT-PCR) as a diagnostic method for the detection of Bordetella pertussis in hospitalized patients aged <1 year with a ...clinical diagnosis of whooping cough, as well as to identify the role of household contacts as a source of infection. Study design This was a prospective, multicenter study of infants aged <1 year who were hospitalized with symptoms suggestive of whooping cough. Nasopharyngeal samples were obtained for culture and RT-PCR testing. The clinical and epidemiologic characteristics and outcomes were analyzed. B pertussis detection and symptoms in household contacts of patients diagnosed with pertussis were studied. Results A total of 286 patients were included; of these, 67.1% had B pertussis and 4.5% had Bordetella spp. Complications occurred in 20% of patients, and the mortality rate was 6.7%. Of 434 contacts studied, 111 were mothers of study infants, representing the most frequently B pertussis– infected group and the main symptomatic contact. Conclusion The use of RT-PCR permits improved detection and diagnosis of pertussis and a better understanding of the epidemiology of sources of infection. The complications and mortality rate of pertussis continue to be high. Household contacts are confirmed as a frequent source of infection of B pertussis in young children.
Chlamydophila pneumoniae is a cause of community-acquired pneumonia (CAP) and responsible for 1-2% of cases in paediatric patients. In Mexico, information on this microorganism is limited. The aim of ...this study was to detect C. pneumoniae using two genomic targets in a real-time PCR and IgM/IgG serology assays in paediatric patients with CAP at a tertiary care hospital in Mexico City and to describe their clinical characteristics, radiological features, and outcomes. A total of 154 hospitalized patients with diagnosis of CAP were included. Detection of C. pneumoniae was performed by real-time PCR of the pst and arg genes. Complete blood cell count, C-reactive protein measurement and IgM and IgG detection were performed. Clinical-epidemiological and radiological data from the patients were collected. C. pneumoniae was detected in 25 patients (16%), of whom 88% had underlying disease (P = 0.014). Forty-eight percent of the cases occurred in spring, 36% in girls, and 40% in children older than 6 years. All patients had cough, and 88% had fever. Interstitial pattern on chest-X-ray was the most frequent (68%), consolidation was observed in 32% (P = 0.002). IgM was positive in 7% and IgG in 28.6%. Thirty-six percent presented complications. Four percent died. A high proportion showed co-infection with Mycoplasma pneumoniae (64%). This is the first clinical report of C. pneumoniae as a cause of CAP in Mexican paediatric patients, using two genomic target strategy and serology. We found a frequency of 16.2% with predominance in children under 6 years of age. In addition; cough and fever were the most common symptoms. Early detection of this pathogen allows timely initiation of specific antimicrobial therapy to reduce development of complications. This study is one of the few to describe the presence of C. pneumoniae in patients with underlying diseases.
Carbapenemases-producing Enterobacteriaceae (CPE) are a worldwide public health emergency. In Mexico, reports of CPE are limited, particularly in the pediatric population. Here, we describe the ...clinical, epidemiological, and molecular characteristics of seven consecutive cases in a third-level pediatric hospital in Mexico City over a four-month period during 2016.
The Enterobacteriaceae identified were three Escherichia coli strains (producing OXA-232, NDM-1 and KPC-2), two Klebsiella pneumoniae strains (producing KPC-2 and NDM-1), one Klebsiella oxytoca strain producing OXA-48 and one Enterobacter cloacae strain producing NDM-1. The majority of patients had underlying disesases, three were immunocompromised, and three had infections involved the skin and soft tissues. Half patients died as a result of CPE infection.
This study represents the first report of E. coli ST131-O25b clone producing NDM-1 in Latin America. In addition, this study is the first finding of K. oxytoca producing OXA-48 and E. coli producing OXA-232 in Mexican pediatric patients.
Our aim in this report was to describe the characteristics of the first clinical isolate of Escherichia coli (EC-PAG-733) harboring the mcr-1 gene found in Mexico. This isolate was obtained from a ...fecal sample from a young child with an oncological condition. We obtained the whole-genome sequence using next-generation sequencing and analyzed the sequence by bioinformatics tools. EC-PAG-733 was resistant to third- and fourth-generation cephalosporins and was susceptible to all carbapenems and amikacin; it was also resistant to ciprofloxacin, levofloxacin, gentamicin and colistin at a minimum inhibitory concentration (MIC) of 4 μg/mL. This isolate was classified as O11:H25-ST457. EC-PAG-733 harbored an ESBL type CTX-M-55 as well as several virulence factors that have been associated with Enteroaggregative Escherichia coli (EAEC). The mcr-1 gene was located within an IncI2 plasmid. The results of this whole genome shotgun project were deposited in DDBJ/ENA/GenBank under the accession number QKXE00000000.
The aim of this study was to identify the presence of group CTX-M-9 extended spectrum beta-lactamases (ESBL) in clinical Escherichia coli isolates from pediatric patients. A total of 404 non-repeated ...positive ESBL E. coli isolates were collected from documented clinical infections in pediatric patients over a 2-year period. The identification and susceptibility profiles were determined using an automated system. Isolates that suggested ESBL production based on their resistance profiles to third and fourth generation cephalosporin and monobactam were selected. ESBL production was phenotypically confirmed using a diffusion method with cefotaxime and ceftazidime discs alone and in combination with clavulanic acid. blaESBL gene identification was performed through PCR amplification and sequencing. Pulsed Field Gel Electrophoresis (PFGE) and Multilocus Sequence Typing (MLST) were performed to establish the clonal relationships of the E. coli isolates. CTX-M-9-type ESBLs were detected in 2.5% of the isolates. The subtypes corresponded to blaCTX-M-14 (n = 4) and blaCTX-M-27 (n = 6). Additionally, coexistence with other beta-lactamases was observed. A clonal relationship was established in three isolates; the rest were classified as non-related. We found seven different sequence type (ST) in CTX-M-9- producing E. coli isolates. ST38 was the most frequent. This study is the first report in Mexico to document the presence of group CTX-M-9 ESBLs in E. coli isolates from pediatric patients.
is the main aetiologic agent of osteoarticular infections (OAIs) in paediatric patients. The aim of this prospective unicenter study was to describe the phenotypic and genotypic characteristics of
...isolates obtained from OAIs in paediatric patients admitted to tertiary care hospital. Through a surveillance program called
, a multidisciplinary team was created and we identified 27 patients with OAIs caused by
from 2019 to 2021. The susceptibility profile, virulence factors, biofilm formation, pulsed-field gel electrophoresis (PFGE), clonal complex (CC) and sequence type (ST) were determined. In addition, the clinical characteristics and evolution of the patients presented six months after the diagnosis of OAIs were described. Ninety-two percent of the isolates were methicillin-sensitive
(MSSA). In methicillin-resistant
(MRSA), SCC
II and SCC
V were detected. The
gene was only observed in MSSA (18.5%) and was associated with highest fever (
=0.015), multiple localization (
0.017), and soft tissue sites of infection beyond the bone (pyomyositis, pulmonary abscess) (
0.017). Biofilm formation was detected in 55.6% of isolates. The most common CC were CC5 and CC30 which represent the most common linages for bone and joint infections worldwide. The isolates were distributed in different STs, and ST672 was predominant. MRSA were associated with a longer duration of intravenous treatment and a prolonged hospital stay (
0.023). Recurrent infection occurred in five children and orthopaedic complications in 33.3% of patients. This is the first study that reflects the epidemiology of
in OAIs in paediatric patients in Mexico; a clear predominance of MSSA distributed in different STs was observed. Our findings highlight that a multidisciplinary team is required for the diagnosis and treatment of OAIs.
The aim of this study was to detect CMY-type beta-lactamases in E. coli isolates obtained from paediatric patients.
In total, 404 infection-causing E. coli isolates resistant to third and fourth ...generation cephalosporins (3GC, 4GC) were collected from paediatric patients over a 2 years period. The identification and susceptibility profiles were determined with an automated microbiology system. Typing of bla
and other beta-lactamase genes (bla
, bla
, bla
, bla
, bla
, bla
, bla
, bla
and bla
) was realized by PCR and sequencing. Phenotypic detection of AmpC-type enzymes was performed using boronic acid (20 mg/mL) and cloxacillin (20 mg/mL) as inhibitors, and the production of extended-spectrum beta-lactamases was determined with the double-disk diffusion test with cefotaxime (CTX) and ceftazidime (CAZ) discs alone and in combination with clavulanic acid. The CarbaNP test and modified carbapenem inhibition method (mCIM) were used for isolates with decreased susceptibility to carbapenems. The clonal origin of the isolates was established by pulsed-field gel electrophoresis (PFGE), phylotyping method and multilocus sequence typing.
CMY-type beta-lactamases were detected in 18 isolates (4.5%). The allelic variants found were CMY-2 (n = 14) and CMY-42 (n = 4). Of the E. coli strains with CMY, the AmpC phenotypic production test was positive in 11 isolates with cloxacillin and in 15 with boronic acid. ESBL production was detected in 13 isolates. Coexistence with other beta-lactamases was observed such as CTX-M-15 ESBL and original spectrum beta-lactamases TEM-1 and TEM-190. In one isolate, the CarbaNP test was negative, the mCIM was positive, and OXA-48 carbapenemase was detected. Phylogroup A was the most frequent (n = 9) followed by B2, E and F (n = 2, respectively), and through PFGE, no clonal relationship was observed. Eleven different sequence types (ST) were found, with ST10 high-risk clone being the most frequent (n = 4). Seventy-two percent of the isolates were from health care-associated infections; the mortality rate was 11.1%.
This is the first report in Mexico of E. coli producing CMY isolated from paediatric patients, demonstrating a frequency of 4.5%. In addition, this is the first finding of E. coli ST10 with CMY-2 and OXA-48.
La neumonía atípica es un término que originalmente se utilizó en pacientes adultos que presentaban neumonías de curso atípico, generalmente leves y de evolución benigna, que eran causadas por ...agentes como: Mycoplasma pneumoniae, Chlamydophila pneumoniae y Legionella pneumophila. En población pediátrica la presentación, tanto clínica como epidemiológica, de las neumonías por M. pneumoniae merece una especial atención ya que no siempre son cursos benignos y pueden existir numerosos cuadros extrapulmonares asociados; el proceso diagnóstico es complejo y poco diferencial de otros agentes etiológicos. Recientemente ha llamado la atención la emergencia de la resistencia a macrólidos en algunos países del mundo, por lo que existen controversias respecto al tratamiento. Estudios numerosos realizados a nivel mundial, particularmente derivados de países asiáticos, han generado nueva información en relación al comportamiento biológico, clínico, epidemiológico, radiológico y respuesta terapéutica de M. pneumoniae en pacientes pediátricos.
En 2015, se aprobó el uso de ceftazidima/avibactam (CZA) para el tratamiento de infecciones complicadas: urinarias, intrabdominales y neumonías adquiridas en hospitales, causadas por bacilos ...Gramnegativos multidrogorresistentes. Su aprobación para uso pediátrico fue en 2019. A pesar de su efectividad inicial, la resistencia a CZA ha ido en aumento, alcanzando un 10% a nivel global. Este artículo ofrece una revisión exhaustiva de los mecanismos de acción de la CZA. Se detallan las principales formas de adquisición de resistencia a este antimicrobiano, como las mutaciones en la carbapenemasa KPC y betalactamasas de espectro extendido (BLEE), sobreexpresión en bombas de eflujo y modificación de porinas. También se revisan investigaciones experimentales para entender las causas de este fenómeno y se destaca la emergencia de resistencia durante el tratamiento con CZA, subrayando la importancia de la epidemiología de esta resistencia para determinar los casos en los que CZA es la mejor opción terapéutica.
Introducción: Ralstonia mannitolilytica es un agente causal de infecciones asociadas al cuidado de la salud. Las especies del género Ralstonia son difíciles de identificar y diferenciar. Nuestro ...objetivo fue identificar y tipificar aislamientos de R. mannitolilytica obtenidos de hemocultivos de pacientes pediátricos. Métodos: Colectamos 10 aislamientos de R. mannitolilytica identificados con un sistema automatizado, un sistema de espectrometría de masas con analizador de tiempo de vuelo y desorción mediante láser asistida por matriz (MALDI-TOF-MS, Matrix-assisted laser desorption/ionization time of flight mass spectrometry) y análisis del gen 16S rRNA. Se determinó el perfil de resistencia y se tipificaron las carbapenemasas a través de PCR y secuenciación. Se estableció la relación clonal de los aislamientos mediante electroforesis en gel de campos pulsados (PFGE). Resultados: El sistema MALDI-TOF-MS y análisis del gen 16S rRNA identificaron a los aislamientos como R. mannitolilytica; todos pertenecieron a la misma clona y fueron resistentes a meropenem, se detectaron a las carbapenemasas OXA-443 y OXA-444 en todos ellos. Conclusiones: Este es el primer reporte de aislamientos de R. mannitolilytica con origen clonal y que poseen las carbapenemasas OXA-443 y OXA-444 en pacientes pediátricos mexicanos.
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