Long-term follow-up of post-cardiac surgery Mycobacterium chimaera infections: A 5-center case series.

OBJECTIVES: In multiple countries, endovascular/disseminated Mycobacterium chimaera infections have occurred in post-cardiac surgery patients in association with contaminated, widely-distributed cardiac bypass heater-cooler devices. To contribute to long-term characterization of this recently recognized infection, we describe the clinical course of 28 patients with 3-7 years of follow-up for survivors. METHODS: Identified at five hospitals in the United States 2010-2016, post-cardiac surgery patients in the cohort had growth of Mycobacterium avium complex (MAC)/M. chimaera from a sterile site or surgical wound, or a clinically compatible febrile illness with granulomatous inflammation on biopsy. Case follow-up was conducted in May 2019. RESULTS: Of 28 patients, infection appeared to be localized to the sternum in four patients. Among 18 with endovascular/disseminated infection who received combination anti-mycobacterial treatment and had sufficient follow-up, 39% appeared to have controlled infection (>12 months), 56% died, and one patient is alive with relapsed bacteremia. While the number of patients is small and interpretation is limited, four (67%) of six patients who had cardiac prosthesis removal/replacement appeared to have controlled infection compared to three (25%) of 12 with retained cardiac prosthesis (p >0.14; Fisher's exact test). CONCLUSIONS: Given poor response to treatment and potential for delayed relapses, post-cardiac surgery M. chimaera infection warrants aggressive treatment and long-term monitoring.

HIV-associated nemaline rod myopathy: role of intravenous immunoglobulin therapy in two persons with HIV/AIDS.

Nemaline rod myopathy is a rare disease associated with muscle weakness and the presence of rod-shaped structures in the muscle fibers. Various acquired conditions have been associated with slow progressing presentations during adulthood. Several cases have been diagnosed in adults with HIV infection. The use of intravenous immunoglobulin (IVIG) has not been previously described for the treatment of these patients. We report the cases of 2 patients with HIV-related nemaline rod myopathy who successfully responded to IVIG therapy.

Complex prosthetic joint infections due to carbapenemase-producing Klebsiella pneumoniae: a unique challenge in the era of untreatable infections.

OBJECTIVES: Limited clinical experience exists regarding the management of prosthetic joint infection (PJI) due to multidrug-resistant (MDR) Gram-negative organisms. We review three cases of carbapenem-resistant Klebsiella pneumoniae (CRKP) complicating PJI. METHODS: This was a retrospective study of all patients at a tertiary care institution with CRKP complicating PJI between January 2007 and December 2010. Demographic data, procedures, organisms involved, length of stay, antibiotic treatments, and outcomes were collected. Antimicrobial susceptibility testing was performed on CRKP isolates, and the mechanism of resistance was ascertained by PCR. RESULTS: This analysis demonstrated that: (1) the CRKP possessed blaKPC and were difficult to eradicate (persistent) in PJI; (2) multiple surgeries and antibiotic courses were undertaken and patients required a prolonged length of stay; (3) resistance to colistin and amikacin emerged on therapy; (4) the same strain of CRKP may be responsible for relapse of infection; (5) significant morbidity and mortality resulted. CONCLUSIONS: These cases highlight the opportunistic and chronic nature of CRKP in PJIs and the need for aggressive medical and surgical treatment. Further investigations of the management of CRKP PJI and new drug therapies for infections due to MDR Gram-negative organisms are urgently needed.

A near fatal case of invasive aspergillosis.

BACKGROUND: Invasive aspergillosis (IA) rarely presents with endobronchial nodules or pseudomembranes on bronchoscopy. We describe a case of invasive aspergillosis in a patient with systemic lupus erythematosus (SLE), in which a fungal etiology was suspected after visualization of scattered, white endobronchial nodules. CASE REPORT: A 36-year-old-female with history of SLE developed cardiorespiratory shock. Bronchoscopy indicated the presence of endobronchial lesions, and serologic studies were consistent with IA. Given high index of suspicion for fungal disease in an immunocompromised host, empiric antifungals were discontinued and voriconazole initiation resulted in a successful therapy. CONCLUSIONS: This case highlights the importance of a high index of suspicion for fungal diseases, especially among critically ill hosts with endobronchial lesions, who develop rapid cardio-respiratory impairment. Failure to recognize endobronchial patterns of fungal infection may lead to treatment delay and adverse clinical outcomes.

Pseudallescheria Boydii pneumonia in an immunocompetent host.

BACKGROUND: Pseudallescheria boydii pneumonia is rarely reported among immunocompetent patients. CASE REPORT: We report a case of a 62 year old white female with pseudallescheria boydii pneumonia. The patient was non-immunocompromised, had a history of mycobacterium avium complex (MAC) infection prior to presentation. After successful response to initial antitubercular therapy, the patient developed recurrent symptoms and bibasilar nodular infiltrates. Second line therapy for MAC failed to improve symptomatology. Pseudallescheria boydii pneumonia was diagnosed from a bronchoscopic biopsy. Treatment with voriconazole resolved her symptomatology and radiological infiltrates. CONCLUSIONS: This case highlights the importance of a high index of suspicion for superimposed fungal infections in patients who are refractory to medical treatment of bacterial pneumonitis such as MAC. Further diagnostic interventions are encouraged when insufficient clinical improvement is observed. Prompt initiation of an antifungal regimen is warranted.

Is there a clinical association of vancomycin MIC creep, agr group II locus, and treatment failure in MRSA bacteremia?

BACKGROUND: The association of vancomycin treatment failure with minimum inhibitory concentration (MIC) creep is concerning, as most isolates are still considered to be in the susceptible range. Several studies have suggested that the accessory gene regulator (agr) group II polymorphism is predictive of vancomycin treatment failure. We assessed the associations between increased vancomycin MIC, agr group II locus, and vancomycin treatment failure in Methicillin-resistant Staphylococcus aureus (MRSA) bacteremias. METHODS: MRSA isolates from 99 inpatient bacteremias were studied. Susceptibility testing was conducted by an automated method (MicroScan) and by the gradient diffusion method (E-test). Vancomycin MICs were stratified into 3 groups for analysis: MIC ≤ 1, MIC > 1 but ≤ 2, and MIC >2 µg/mL. Strains were typed by repetitive-polymerase chain reaction analysis and the agr locus was identified by multiplex polymerase chain reaction. Failure of vancomycin treatment was defined as persistent bacteremia after 72 hours, death at 30 days, or treatment change due to clinical failure. RESULTS: Among 99 bacteremic patients, there were 82 agr group II and 15 agr group I isolates. There was no relationship between higher vancomycin MICs and isolate agr II loci (42 of 82) (P=0.59). Earlier vancomycin exposure was significantly associated with increased MIC (P=0.03). Vancomycin treatment failure was observed in 12 patients: 3 required an alternate regimen, 4 had persistent positive cultures, and 5 whose deaths were attributable to MRSA infection. Survival in agr group II was 57 of 82 (69%) versus agr group I in which it was 14 of 15 (93%), (P=0.06). CONCLUSIONS: We did not identify any significant association between MIC creep and vancomycin failure or between higher vancomycin MICs and agr group II. However, a higher mortality was seen in agr group II than agr group I.