Case Report: Molecular Characterization of Bloodstream Infections due to Carbapenem-Resistant Acinetobacter baumannii: A Pediatric Case Series.

Acinetobacter baumannii poses a significant threat to public health due to the high rate of multidrug-resistant strains. However, information on the molecular characterization of carbapenem-resistant Acinetobacter baumannii (CRAB) bloodstream infections in children is scarce. This study aimed to describe the molecular characterization of carbapenem-resistant A. baumannii infections in children from a hospital in Mexico. A retrospective study was conducted during the period 2017-2022. Clinical and demographic data were collected from the clinical records. Mass spectrometry was used for the identification of the strains. To confirm A. baumannii strains, a polymerase chain reaction (PCR) method was applied using a gyrB sequence. The carbapenemase-encoding resistance genes were detected by PCR. Six cases of CRAB were documented, including five in neonates. The median intensive care unit stay was 20 days, and all cases had an invasive medical device. Half of the patients had at least one medical condition. A high prevalence of coresistance was observed in most of the antibiotic groups. Three of the six strains coharbored carbapenemase genes: blaOXA-51, blaOXA-24, and blaIMP. Mortality was reported in two neonate patients. The present study shows a high rate of coharboring blaOXA-51, blaOXA-24, and blaIMP-1, which has a direct impact on therapeutic decisions. Implementation of antimicrobial stewardship programs is urgent to stop the spread of this microorganism.

Carbapenem-Resistant Acinetobacter baumannii Infection in Children From a Third-Level Hospital in Mexico: Clinical Characteristics and Molecular Epidemiology.

BACKGROUND: Acinetobacter baumannii has emerged as a threat to public health due to the high prevalence of multidrug-resistant isolates. Information regarding the clinical and molecular characterization of carbapenem-resistant A. baumannii (CRAB) infections in children is scarce. Our study aimed to describe the clinical and molecular characteristics of CRAB infections in children from a third-level center in Mexico. METHODS: Consecutive cases of CRAB infections were documented during 2017-2022. Clinical and demographic data were collected from clinical records. Mass spectrometry was used for the identification of the isolates. The identification of A. baumannii strains was confirmed by conducting a polymerase chain reaction (PCR) assay targeting the gyrB sequence. In addition, the carbapenemase-encoding resistance genes were detected by PCR. RESULTS: Twenty-one cases of CRAB infections were documented: 76% female and 62% were neonates. The median hospital length of stay at the time of positive culture was 37 days (interquartile range, 13-54). Sixty-four percent of the isolates were recovered from bronchial secretions. A co-resistance rate greater than 60% was observed for most groups of antibiotics. All carbapenem-resistant isolates carried blaOXA-24 genes. BlaIMP genes were detected in half of the cases, with all strains co-harboring blaOXA-24 genes. CONCLUSIONS: The present study demonstrated a high proportion of CRAB infections in the neonatal population, a high prevalence of co-resistance to antibiotics, and a high rate of isolates carrying blaOXA-24 and blaIMP genes. CRAB is a significant concern due to the mortality rate and the lack of therapeutic alternatives; implementing infection prevention and control programs is urgent to stop the spread of carbapenem-resistant A. baumannii.

Facklamia hominis pyelonephritis in a pediatric patient: first case report and review of the literature.

BACKGROUND: Pyelonephritis is one of the most serious bacterial illnesses during childhood. Gram-negative organisms account for up to 90% of the cases. Gram-positive bacteria are uncommon causes of urinary tract infections, and only a few cases caused by Facklamia hominis have been reported in the literature. CASE PRESENTATION: A five-year-old girl with tracheostomy and gastrostomy and past medical history of congenital lymphangioma presented with a two-week history of with intermittent fever, frequent urination, and vesical tenesmus. Diagnosis of pyelonephritis was made. Urine culture reported colonies with alpha-hemolysis in blood agar at 48-h of incubation and Facklamia hominis was identified by MALDI-TOF. The patient was successfully treated with gentamicin. CONCLUSIONS: This is the first reported case of pyelonephritis by Facklamia hominis in a child, and the second involving infection in a pediatric patient. Although this pathogen is uncommon, current treatment of F. hominis is a challenge for physicians. This case illustrates the requirement to standardize identification and treatment of care to avoid treatment failure and antimicrobial resistance.

Circulation of Highly Drug-Resistant Clostridium difficile Ribotypes 027 and 001 in Two Tertiary-Care Hospitals in Mexico.

OBJECTIVE: To assess drug susceptibility and characterize Clostridium difficile ribotypes in isolates from two tertiary-care hospitals in Mexico. METHODS: Isolates were evaluated for genotyping, antimicrobial susceptibility testing and detection of mutations associated with drug resistance. PCR ribotyping was performed using a combination of gel-based and capillary electrophoresis-based approaches. RESULTS: MIC50 and MIC90 were ≥128 mg/L for ciprofloxacin, erythromycin, clindamycin, and rifampicin. There was no reduced susceptibility to metronidazole or tetracycline; however, reduced susceptibility to vancomycin (≥4 mg/L) and fidaxomicin (≥2 mg/L) was detected in 50 (40.3%) and 4 (3.2%) isolates, respectively. Furthermore, the rpoB Arg505Lys mutation was more frequently detected in isolates with high minimum inhibitory concentration (MIC) to rifampicin (≥32 mg/L) (OR = 52.5; 95% CI = 5.17-532.6; p < 0.000). Of the 124 C. difficile isolates recovered, 84 (66.7%) were of ribotype 027, 18 (14.5%) of ribotype 001, and the remainder were other ribotypes (353, 255, 220, 208, 176, 106, 076, 020, 019, 017, 014, 012, 003, and 002). CONCLUSION: Ribotypes 027 and 001 were the most frequent C. difficile isolates recovered in this study, and demonstrated higher MICs. Furthermore, we found four isolates with reduced susceptibility to fidaxomicin, raising a concern since this drug is currently unavailable in Mexican Hospitals.