A Case of Successful Treatment of Recurrent Urinary Tract Infection by Extended-Spectrum ß-Lactamase Producing Klebsiella pneumoniae Using Oral Lyophilized Fecal Microbiota Transplant.

Recurrent urinary tract infections (UTIs) are a challenging clinical entity that can be frustrating for patient and physician alike. Repeated rounds of antibiotics can select for multidrug-resistant organisms, further complicating care. We describe the successful use of fecal microbiota transplantation (FMT) for the treatment of recurrent extended-spectrum ß-lactamase (ESBL)-producing Klebsiella pneumoniae UTIs in a patient with an ileal conduit and urostomy. In the 18 months after FMT, the patient had not experienced new infections with ESBL-producing organisms. The urine and stool microbiomes of the patient were tracked before and post-FMT using 16s RNA sequencing with measurement of α-diversity. Sequencing of the recipient microbiota did not mirror the donor stool taxa at either site, but an increase in the relative proportion of the genus Bacteroides as compared with Prevotella was noted in the stool post-transplant. FMTs may be a promising treatment option for recurrent multidrug-resistant infections.

Long-Term Compassionate Use of Cefiderocol To Treat Chronic Osteomyelitis Caused by Extensively Drug-Resistant Pseudomonas aeruginosa and Extended-Spectrum-ß-Lactamase-Producing Klebsiella pneumoniae in a Pediatric Patient.

We report a 15 year-old Nigerian adolescent male with chronic osteomyelitis caused by an extensively drug-resistant (XDR) Pseudomonas aeruginosa strain of sequence type 773 (ST773) carrying blaNDM-1 and an extended spectrum ß-lactamase (ESBL)-producing Klebsiella pneumoniae strain. The patient developed neurological side effects in the form of circumoral paresthesia with polymyxin B and asymptomatic elevation of transaminases with aztreonam (used in combination with ceftazidime-avibactam). Cefiderocol treatment for 14 weeks plus bone implantation resulted in apparent cure and avoided amputation.

Resistance to Ceftazidime-Avibactam Is Due to Transposition of KPC in a Porin-Deficient Strain of Klebsiella pneumoniae with Increased Efflux Activity.

Ceftazidime-avibactam is an antibiotic with activity against serine beta-lactamases, including Klebsiella pneumoniae carbapenemase (KPC). Recently, reports have emerged of KPC-producing isolates resistant to this antibiotic, including a report of a wild-type KPC-3 producing sequence type 258 Klebsiella pneumoniae that was resistant to ceftazidime-avibactam. We describe a detailed analysis of this isolate, in the context of two other closely related KPC-3 producing isolates, recovered from the same patient. Both isolates encoded a nonfunctional OmpK35, whereas we demonstrate that a novel T333N mutation in OmpK36, present in the ceftazidime-avibactam resistant isolate, reduced the activity of this porin and impacted ceftazidime-avibactam susceptibility. In addition, we demonstrate that the increased expression of blaKPC-3 and blaSHV-12 observed in the ceftazidime-avibactam-resistant isolate was due to transposition of the Tn4401 transposon harboring blaKPC-3 into a second plasmid, pIncX3, which also harbored blaSHV-12, ultimately resulting in a higher copy number of blaKPC-3 in the resistant isolate. pIncX3 plasmid from the ceftazidime-avibactam resistant isolate, conjugated into a OmpK35/36-deficient K. pneumoniae background that harbored a mutation to the ramR regulator of the acrAB efflux operon recreated the ceftazidime-avibactam-resistant MIC of 32 µg/ml, confirming that this constellation of mutations is responsible for the resistance phenotype.