Infecciones por Elizabethkingia spp. en un hospital universitario: coinfección con SARS-CoV-2 y primer reporte de Elizabethkingia anophelis en Chile / Elizabethkingia spp. infections in a university hospital: coinfection with SARS-CoV-2 and first report of Elizabethkingia anophelis in Chile

INTRODUCCIÓN: Elizabethkingia es un género de bacterias gramnegativas cuya relevancia como patógeno oportunista en hospederos inmunocomprometidos y pacientes críticos ha sido reconocida progresivamente en los últimos años. Este género está compuesto principalmente por E. meningoseptica, E. anophelis y E. miricola. Si bien inicialmente E. meningoseptica fue considerada la especie patógena más relevante, gracias a los avances en las técnicas de identificación microbiológica se ha reconocido a E. anophelis como el principal patógeno de este grupo. OBJETIVO: Caracterizar los casos de infecciones por Elizabethkingia spp. en una red de salud y realizar una breve revisión de esta infección. MATERIAL Y MÉTODOS: Se realizó una revisión de los cultivos positivos para Elizabethkingia spp. en el Laboratorio de Microbiología de la Red de Salud UC-CHRISTUS (Chile) entre los años 2017 y 2021. RESULTADOS: Se obtuvo 17 cultivos positivos correspondientes a siete casos clínicos, todos procedentes de un hospital universitario. Todos los casos poseían factores de riesgo conocidos de infección por Elizabethkingia spp. incluyendo uso de antimicrobianos recientes, por ejemplo, el uso previo de carbapenémicos en 85,7% de los pacientes. Cuatro casos se presentaron en pacientes con neumonía por SARS-CoV-2, una coinfección no previamente reportada en la literatura. Elizabethkingia anophelis fue identificada mediante secuenciación de ARN ribosomal en 80% de las cepas recuperadas, lo que corresponde al primer reporte de esta especie en Chile CONCLUSIÓN: Comunicamos la experiencia clínica de infecciones por este género en un hospital universitario de Chile, incluyendo los primeros casos de coinfección en pacientes cursando neumonía por SARS-CoV-2 y la primera identificación de Elizabethkingia anophelis en Chile.

BACKGROUND: Elizabethkingia is a genus of gramnegative bacteria whose relevance as an opportunistic pathogen in immunosuppressed hosts and critically ill patients has been progressively recognized in recent years. This genus is mainly composed of E. meningoseptica, E. anophelis, and E. miricola. Although E. meningoseptica was initially reported as the most relevant pathogenic species, thanks to advances in microbiological identificaron techniques E. anophelis has been recognized as the main pathogen of this group. AIM: To characterize Elizabethkingia spp.'s infections in a health network and make a brief review of this infection. METHOD: We conducted a review of clinical cultures that were positive for Elizabethkingia sp. in the Microbiology Laboratory of the UC-CHRISTUS Health Network (Chile), between 2017 and 2021. RESULTS: Seventeen positive cultures were obtained corresponding to seven clinical cases, all originating from a university hospital. All cases had known risk factors for Elizabethkingia sp. infection, including recent use of antibiotics. Notably, previous use of carbapenems was present in 85.7% of the patients. Four cases occurred in patients with SARS-CoV-2 pneumonia, a coinfection not previously reported in the literature. Elizabethkingia anophelis was identified by ribosomal RNA sequencing in 80% of the recovered strains, which corresponds to the first report of this species in Chile. CONCLUSION: We report the clinical experience of a university hospital with infections by Elizabethkingia spp., including the first cases of coinfection in patients with SARS-CoV-2 pneumonía and the first identification of Elizabethkingia anophelis in Chile.

Myroides odoratimimus, una causa infrecuente de infección de tejidos blandos y osteomielitis / Myroides odoratimimus, a rare cause of soft tissue infection and osteomyelitis: case report

Resumen Las infecciones por bacterias gramnegativas del género Myroides son muy poco frecuentes y generalmente afectan la piel y tejidos blandos de pacientes con algún grado de inmunocompromiso. Presentamos un caso de una mujer de 23 años, con antecedentes de mielomeningocele operado y pie bot, que cursó con una infección profunda de la extremidad inferior derecha por Myroides odoratimimus. La identificación de especie se realizó con técnica de MALDI-TOF. El tratamiento fue inicialmente con meropenem y ajustado a ciprofloxacina, junto con realizar una amputación supramaleolar derecha.

Abstract Infections due to Gram-negative bacteria of the genus Myroides are very rare and generally affect the skin and soft tissues of patients with some degree of immunocompromise. We present a case of a 23-year-old patient with a history of myelomeningocele surgically resolved at 3 years of age and bot foot, who presented with a deep infection of the right lower extremity by Myroides odoratimimus. The species identification was carried out with MALDI-TOF and the treatment was initially carried out with meropenem and finally then ciprofloxacin, in addition to right supramaleolar amputation.

Bacteremia due to Weeksella virosa in a pediatric patient with embryonal rhabdomyosarcoma / Bacteriemia por Weeksella virosa en un paciente pediátrico con rabdomiosarcoma embrionario

Abstract Background: Weeksella virosa is one of the two species of the genus Weeksella. Clinical disease due to this bacterium in humans is rare, for which only nine cases have been reported in the literature. Case report: A 4-year-old male patient was diagnosed with a left orbit rhabdomyosarcoma Stage III and was admitted to a northeast third level referral center in Mexico. Aerobic, non-pigmented, Gram-negative rod was isolated from a blood culture. W. virosa was identified by Sensititre™ ARIS. This organism has been described in cases of spontaneous bacterial peritonitis, sepsis, pneumonia, ventriculitis, and urinary tract infection. Conclusions: Clinicians should consider the diagnosis of W. virosa bacteremia in cases involving immunocompromised patients with oral lesions, although it is infrequent. To the best of our knowledge, this is the first clinical report of W. virosa bacteremia described in an immunocompromised pediatric patient.

Resumen Introducción: Weeksella virosa es una de las dos especies del género Weeksella. En los humanos, los reportes de infección por este microorganismo son raros. Solo se han reportado nueve casos en la literatura. Caso clínico: Paciente masculino de 4 años con diagnóstico de rabdomiosarcoma embrionario de órbita izquierda en estadio III, que fue atendido en un hospital de tercer nivel en el noreste de México. Se realizó un hemocultivo, a partir del cual se aisló un bacilo gramnegativo aerobio, no pigmentado. Se identificó W. virosa mediante Sensititre™ ARIS. Este microorganismo ha sido descrito en casos de peritonitis bacteriana espontánea, sepsis, neumonía, ventriculitis e infección del tracto urinario. Conclusiones: Aunque los casos de bacteriemia por W. virosa son raros, los clínicos deben considerar este agente en pacientes inmunocomprometidos con lesiones orales. Hasta donde se conoce, este es el primer caso que se describe de bacteriemia por W. virosa en un paciente pediátrico inmunocomprometido.

Draft genome sequence of Vitellibacter aquimaris D-24T isolated from seawater

ABSTRACT Vitellibacter aquimaris D-24T (=KCTC 42708T = DSM 101732T), a halophilic marine bacterium, was isolated from seawater collected from Desaru beach, Malaysia. Here, we present the draft genome sequence of D-24T with a genome size of approximately 3.1 Mbp and G + C content of 39.93%. The genome of D-24T contains genes involved in reducing a potent greenhouse gas (N2O) in the environment and the degradation of proteinaceous compounds. Genome availability will provide insights into potential biotechnological and environmental applications of this bacterium.

CspB of an arctic bacterium, Polaribacter irgensii KOPRI 22228, confers extraordinary freeze-tolerance

ABSTRACT Freezing temperatures are a major challenge for life at the poles. Decreased membrane fluidity, uninvited secondary structure formation in nucleic acids, and protein cold-denaturation all occur at cold temperatures. Organisms adapted to polar regions possess distinct mechanisms that enable them to survive in extremely cold environments. Among the cold-induced proteins, cold shock protein (Csp) family proteins are the most prominent. A gene coding for a Csp-family protein, cspB, was cloned from an arctic bacterium, Polaribacter irgensii KOPRI 22228, and overexpression of cspB greatly increased the freeze-survival rates of Escherichia coli hosts, to a greater level than any previously reported Csp. It also suppressed the cold-sensitivity of an E. coli csp-quadruple deletion strain, BX04. Sequence analysis showed that this protein consists of a unique domain at its N-terminal end and a well conserved cold shock domain at its C-terminal end. The most common mechanism of Csp function in cold adaption is melting of the secondary structures in RNA and DNA molecules, thus facilitating transcription and translation at low temperatures. P. irgensii CspB bound to oligo(dT)-cellulose resins, suggesting single-stranded nucleic acid-binding activity. The unprecedented level of freeze-tolerance conferred by P. irgensii CspB suggests a crucial role for this protein in survival in polar environments.

Myroides odoratimimus soft tissue infection in an immunocompetent child following a pig bite: case report and literature review

Members of the genus Myroides are aerobic Gram-negative bacteria that are common in environmental sources, but are not components of the normal human microflora. Myroides organisms behave as low-grade opportunistic pathogens, causing infections in severely immunocompromised patients and rarely, in immunocompetent hosts. A case of Myroides odoratimimus cellulitis following a pig bite in an immunocompetent child is presented, and the medical literature on Myroides spp. soft tissue infections is reviewed.

Analysis of outer membrane proteins of Riemerella antipestifer / 生物工程学报

An isolated virulence Riemerella anatipestifer strain passaged 200 times on TSB agar were used for the virulent to avirulent conversion. The effects of passage on biological properties of outer membrane proteins (OMPs) were investigated using the virulent and avirulent strains. Transmission electron microscopy demonstrated that the avirulent strain produced lower amounts of outer membrane vesicles and the outer membrane decreased, the cytoplasmic appearance jumbled. The OMPs of the virulent strain agglutinated only in RA serotype 2 antisera, whereas the OMPs of the avirulent strain agglutinated in antisera of RA 1, 2, 10 and 11. SDS-PAGE Analysis showed the OMPs profiles of both strains were similar but the immunoblotting profiles were different. The protective immunity against Riemerella anatipestifer infection was investigated by immunizations with OMPs in ducks. ELISA results showed that the OMPs induced the production of antibodies in immunized ducks, but the OMPs of virulence strain induced higher antibody titers than the attenuated strain (P < 0.05). RA2 group showed significantly higher survival rates (100%) than RA200 group (0%) after challenged with the homologous virulent strain. The ompA gene of both stains were also amplified by PCR, nucleotide homology was 99.9%. In conclusion, OMPs of virulent RA strain are suitable candidates for vaccine development. Biological properties of OMPs undergoes significant changes during serial passage and suggest that vigilance should be used when extrapolating data obtained from the study of high-passage strains.

Oerskovia turbata and Myroides species: rare isolates from a case of acalculus cholecystitis.

Here we report a case of acalculus cholecystitis, which presented with features of obstructive jaundice of one-week duration. The patient underwent cholecystectomy and bile grew a mixed culture of Oerskovia turbata and Myroides spp. Being a rare isolate, characteristic features of the former are described in this report. The patient recovered without any complication.