Hypervirulent and hypermucoviscous extended-spectrum ß-lactamase-producing Klebsiella pneumoniae and Klebsiella variicola in Chile.

Convergence of virulence and antibiotic-resistance has been reported in Klebsiella pneumoniae, but not in Klebsiella variicola. We, hereby, report the detection and genomic characterization of hypervirulent and hypermucoviscous K. pneumoniae and K.variicola recovered in Chile from health-care associated infections, which displayed resistance to broad-spectrum cephalosporins. One hundred forty-six K. pneumoniae complex isolates were screened by hypermucoviscosity by the "string test." Two hypermucoid isolates, one hypermucoviscous K. pneumoniae (hmKp) and one K. variicola (hmKv), were further investigated by whole-genome sequencing. In vivo virulence was analyzed by the Galleria mellonella killing assay. In silico analysis of hmKp UCO-494 and hmKv UCO-495 revealed the presence of multiple antibiotic-resistance genes, such as blaCTX-M-1, blaDHA-1 and blaLEN-25 among others clinically relevant resistance determinants, including mutations in a two-component regulatory system related to colistin resistance. These genetic features confer a multidrug-resistant (MDR) phenotype in both strains. Moreover, virulome in silico analysis confirmed the presence of the aerobactin gene iutA, in addition to yersiniabactin and/or colicin V encoding genes, which are normally associated to high virulence in humans. Furthermore, both isolates were able to kill G. mellonella and displayed higher virulence in comparison with the control strain. In summary, the convergence of virulence and the MDR-phenotype in K. pneumoniae complex members is reported for the first time in Chile, denoting a clinical problem that deserves special attention and continuous surveillance in South America.

[Invasive extrapulmonary infections due to Streptococcus pneumoniae. Report of three fatal cases and review]. / Infecciones invasivas extrapulmonares por Streptococcus pneumoniae. Presentación de tres casos fatales y revisión.

Streptococcus pneumoniae is a most important patogen in respiratory and meningeal infections. It is also a relevant agent of septic arthritis, pericarditis, acute endocarditis and spontaneous peritonitis in cirrhotic patients with ascites. It is less well known as a cause of infections in many other sites, including abdominal organs and soft tissues, which may be very severe. In this report, we describe three fatal cases (phlegmonous gastritis, cellulitis and primary peritonitis without pre-existing ascites) due to Streptococcus pneumoniae. In the last years it has become clear that this agent can cause infections at almost any body level, which is worth remembering. We review the literature and discuss some clinical aspects of two rare infectious syndromes, like primary peritonitis without previous ascites and phlegmonous gastritis.

[Three years of acute bacterial meningitis in the pediatric service at the Temuco Regional Hospital]. / Tres años de meningitis bacteriana aguda en servicio de pediatria del Hospital Regional de Temuco.

The aim of this work was to study the clinical, epidemiological and laboratory features of 90 children, hospitalized between 1988 and 1991 with the diagnosis of acute bacterial meningitis in a region with a high proportion of aboriginal population. Twenty six percent of studied patients were of mapuche origin. The causative organism was identified in 82% of cases (H influenzae in 38% of cases, S pneumoniae in 29% and N meningitidis in 10%). H influenzae was resistant to ampicillin in 16% of cases and resistant to chloramphenicol in 4%. This agent was identified in 52% of patients of mapuche origin compared with 33% of non mapuche patients. Seventy three percent of children were less than 2 years old. Thirty seven percent of children had complications during hospitalization, 12 children died (13.3%) and 38% of children had neurological sequelae at the moment of discharge.

[Diagnosis of bacterial meningitis by latex agglutination tests]. / Diagnóstico de meningitis bacteriana aguda por aglutinación con partículas de látex.

Fifty samples of cerebrospinal fluid (CSF) from patients with acute bacterial meningitis were studied with direct gram examination, culture and latex agglutination. Twenty one of these samples had previous antimicrobial treatment. In 42 patients, blood cultures were also made. Thirty control CSF samples were also studied. The diagnostic yield of CSF culture was 72%, of direct gram examination 74% and latex agglutination 80%. All the techniques as a whole has a diagnostic yield of 92%. In the 21 CSF samples with previous antimicrobial treatment, culture was positive in 47.6% and latex agglutination in 85.7%. All control CSF samples were negative. It is concluded that the diagnostic yield of latex agglutination test in patients with previous antimicrobial treatment is significantly better than culture.

[Shigellosis in children of the IX region of Chile: clinical and epidemiologic aspects and antibiotic sensitivity]. / Shigellosis infantil en la IX region: aspectos clinicos, epidemiologicos y estudio de sensibilidad.

Ninety four children with diarrhea and a positive stool culture for Shigella, hospitalized at the Hospital Regional de Temuco, were studied. Forty six percent of patients were less than two years old. Forty two percent of microorganisms were resistant to Ampicillin, 45% to trimethoprim/sulfamethoxazole, 8% to tetracycline and none to chloramphenicol. Isolated species were Shigella flexneri 83% and Shigella sonnei 17%. Seventy nine percent of patients had fever, 60% dysentery and 21.3% seizures. Ninety two percent of symptomatic family contacts had a positive stool culture for Shigella. Due to the high incidence of resistance to ampicillin and trimethoprim/sulfamethoxazole, these antimicrobials are not recommended as the first choice treatment of Shigellosis in the Ninth region of Chile.