Selective digestive decontamination with oral colistin plus gentamicin for persistent bacteraemia caused by non-carbapenemase-producing carbapenem-resistant Klebsiella pneumoniae in a neutropenic patient.

BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKp) have become an increasing public health problem worldwide. While most CRKp around the world harbour a carbapenemase enzyme, the clinical relevance of non-carbapenemase-producing CRKp (non-CP-CRKp) is increasingly recognized. Selective digestive decontamination (SDD) has been proven successful as a decolonization strategy for patients colonized with Gram-negatives in the ICU. However, it is not regularly used to treat invasive infections. OBJECTIVES: To report the use of SDD as a useful strategy for managing recalcitrant CRKp bloodstream infections. PATIENTS AND METHODS: We present a neutropenic patient with a recalcitrant bloodstream infection with non-CP-CRKp treated with SDD. Besides, genomic analyses of five isolates of non-CP-CRKp was performed. RESULTS: After 11 days of SDD treatment with oral colistin and gentamicin, bacteraemia was successfully eradicated. Genomic analysis indicates a fully carbapenem-resistant phenotype evolved in vivo and suggests that the mechanism of carbapenem resistance in our strains relates to gene amplification of narrow-spectrum ß-lactamases. CONCLUSIONS: Our report highlights that SDD might be a useful strategy to manage CRKp bloodstream infections, when intestinal translocation is the likely source of the bacteraemia. In addition, the development of a resistant phenotype during therapy is worrisome as therapies directed against these organisms are likely to favour the amplification process.

Extensively Drug-Resistant Pseudomonas aeruginosa ST309 Harboring Tandem Guiana Extended Spectrum ß-Lactamase Enzymes: A Newly Emerging Threat in the United States.

BACKGROUND: Treatment of serious infections due to multidrug-resistant (MDR) Pseudomonas aeruginosa remains a challenge, despite the introduction of novel therapeutics. In this study, we report 2 extensively drug-resistant clinical isolates of sequence type (ST) 309 P aeruginosa resistant to all ß-lactams, including the novel combinations ceftolozane/tazobactam, ceftazidime/avibactam, and meropenem/vaborbactam. METHODS: Isolates were sequenced using both short-read (Illumina) and long-read technology to identify resistance determinants, polymorphisms (compared with P aeruginosa PAO1), and reconstruct a phylogenetic tree. A pair of ß-lactamases, Guiana extended spectrum ß-lactamase (GES)-19 and GES-26, were cloned and expressed in a laboratory strain of Escherichia coli to examine their relative impact on resistance. Using cell lysates from E coli expressing the GES genes individually and in tandem, we determined relative rates of hydrolysis for nitrocefin and ceftazidime. RESULTS: Two ST309 P aeruginosa clinical isolates were found to harbor the extended spectrum ß-lactamases GES-19 and GES-26 clustered in tandem on a chromosomal class 1 integron. The presence of both enzymes in E coli was associated with significantly elevated minimum inhibitory concentrations to aztreonam, cefepime, meropenem, ceftazidime/avibactam, and ceftolozane/tazobactam, compared with those expressed individually. The combination of ceftazidime/avibactam plus aztreonam was active in vitro and used to achieve cure in one patient. Phylogenetic analysis revealed ST309 P aeruginosa are closely related to MDR strains from Mexico also carrying tandem GES. CONCLUSIONS: The presence of tandem GES-19 and GES-26 is associated with resistance to all ß-lactams, including ceftolozane/tazobactam. Phylogenetic analysis suggests that ST309 P aeruginosa may be an emerging threat in the United States.

Food Insecurity, Not Stress is Associated with Three Measures of Obesity in Low-Income, Mexican-American Women in South Texas.

OBJECTIVE: To determine the relationship between obesity, food insecurity and perceived stress in very low income Mexican American women. DESIGN: Cross-sectional baseline data analysis of a randomized clinical trial. SETTING: Texas-Mexico border region of South Texas. SUBJECTS: Very Low Income Mexican American Women. RESULTS: The relationship between obesity and food insecurity in a sample of very low income Hispanic women living in South Texas depends on the measure of obesity and the dimension of food insecurity. The only measure of food insecurity associated with all measures of obesity was often not having enough money to afford to eat balanced meals. Waist circumference was associated with the most dimensions of food insecurity, while BMI had the least associations. Finally, perceived stress was not significantly associated with BMI, waist circumference or percent body fat when adjusted for other covariates. CONCLUSIONS: We have found a strong and significant relationship between food insecurity related to having enough resources to eat a balanced diet and BMI, waist circumference, and percent body fat in low-income Mexican American women. While behavioural change is an important strategy for reducing obesity, consideration may need to be made as to how food access with high nutritional value, may be in and of itself a contributing factor in obesity in low income populations.