Bacterial Meningitis Caused by Hypervirulent <i>Klebsiella pneumoniae</i> Capsular Genotype K54 with Development of Granuloma-like Nodal Enhancement in the Brain during the Subacute Phase

Abstract

A 72-year-old man was admitted to the emergency department due to coma. The cerebrospinal fluid cell count was 40,080 cells/μL, and Klebsiella pneumoniae was detected on culture. Stretching the bacterial colonies on an agar plate showed the formation of a viscous string with a length exceeding 5 mm, indicating hypervirulent K. pneumoniae (hv-KP). A genome analysis suggested hv-KP capsular genotype K54 with sequence type 29. Although no brain abscess was detected on contrast-enhanced computed tomography on Day 4 or on magnetic resonance imaging (MRI) on Day 7, contrast-enhanced MRI on Day 23 showed granuloma-like nodal enhancement on the surface of the left insula. Antibacterial therapy was continued until the enhancement disappeared on Day 40. MRI may help determine the duration required for antibacterial therapy. After six months, the patient was discharged and remained free from recurrence.

Epidemiology and risk factors of neurosurgical bacterial meningitis/encephalitis induced by carbapenem resistant Enterobacteriaceae

“…Meningitis/encephalitis caused by Enterobacteriaceae remains a therapeutic challenge as the effective antibiotic is severely limited. The number of Enterobacteriaceae meningitis/encephalitis in neurosurgery patients have increased in recent years [1,2]. In this retrospective study, Enterobacteriaceae, and especially CRE, played a significant role in neurosurgical bacterial meningitis/encephalitis with strong invasiveness, high toxicity, high morbidity and mortality rates.…”

“…Meningitis caused by neurosurgery has posed a formidable challenge, resulting in severe morbidity with a prolonged length of hospital stay and higher hospital costs [1,2]. Significantly varied rates of meningitis caused by neurosurgery have been reported, ranging from 0.72 to >8% [3e5].…”

Clinical and Molecular Characteristics of Klebsiella pneumoniae Isolates Causing Bloodstream Infections in Japan: Occurrence of Hypervirulent Infections in Health Care

“…Severe community-acquired infections caused by K. pneumoniae isolates other than capsular genotype K1 have been reported from a number of countries and have gained attention in recent years (4,5). While most of these isolates have capsule types classically recognized as high risk for invasive infections (K1, K2, K5, K20, K54, and K57), some of them have capsules of other types (6).…”

“…For example, hvKp isolates of capsular genotype K2 belong to different STs (e.g., ST65, ST86, and ST380) (4,7). In addition to liver abscess, clinical presentations of severe infections caused by hvKp include necrotizing fasciitis, osteomyelitis, and meningitis and are sometimes accompanied by disseminated infections (5,8,9). hvKp has also been associated with community-acquired pneumonia with bacteremia (10,11).…”

Mass spectrometry and associated technologies delineate the advantageously biomedical capacity of siderophores in different pathogenic contexts

“…A line of studies showed that aerobactin assembly will help form potential anti-virulence strategies and advance our understanding of siderophore biosynthesis. Aerobactin plays a key role to mediate the enhanced virulence of a hypervirulent pathotype of Klebsiella pneumoniae, a causative agent of hepatic abscesses, endophthalmitis, meningitis, osteomyelitis, pneumonia, and necrotizing fasciitis (Kashani & Eliott, 2013;Kwon et al, 2013;Vandevelde & Stepanovic, 2014;Ng & Frazee, 2015;Takahashi et al, 2015;Prokesch et al, 2016;Iwasaki et al, 2017;Bailey et al, 2018). Siderophores and substrate-binding proteins (SBPs) are employed by gramnegative bacteria to transport transition metals such as iron.…”