In this episode, Dr. Kimothy Smith and Christian Railsback discuss Klebsiella – a gram-negative bacteria that causes various healthcare-associated infections. Though Klebsiella has a broad scope at the species and sub-species levels, this episode concentrates on common characteristics, environments, and levels of drug resistance. A transcript of the conversation appears below. More about Klebsiella:CDC’s Opportunistic Pathogens of Premise Plumbing listKlebsiella pneumoniae in Healthcare SettingsKlebsiella Pneumonia Stay tuned for more episodes, posting on the first Thursday of each month. Subscribe to our show wherever you get your podcasts and find more info at weebeastiespodcast.com The Wee Beasties podcast is a production of Nephros, Inc., a leading water technology company providing filtration and pathogen detection solutions to the medical and commercial markets. ***SHOW TRANSCRIPT: Christian: I am back with Dr. Kimothy Smith. Kimothy, welcome back! Kimothy: Thanks, Christian. Christian: So, what’s our bug for today? Kimothy: Klebsiella. Christian: Klebsiella. Reminds me of something I would get whacked with by my grandmother. Kimothy: Well, Christian, Klebsiella is likely slightly more insidious than your grandmother, it can lead to meningitis. But I don’t know I never met your grandmother. Christian: You’re right, that’s slightly more insidious than my grandmother. Okay, I’m really interested to hear how Klebsiella leads to meningitis or other pathologies of similar mortality and morbidity. But let’s start small today. Let’s make this easily digestible. This is a waterborne pathogen like the previous pathogens we’ve discussed. How do we differentiate this bug? Kimothy: Let me first say the genus, Klebsiella, has a fairly broad scope and extensive list at the species and sub-species levels. For the purpose of remaining very clear I’ll limit my descriptions to the most clinically significant species and sub-species. Namely, K. pneumoniae and K. oxytoca. Both of which can be pronounced in different ways, by different people. Part of the justification for limiting to just these two is that 90% of the waterborne pathogen infections caused by Klebsiella are these two species. Christian: Okay, so that means the microbiologists out there are going to express scorn for our unwillingness to spend the full day discussing the catalogue of attributes across the genus, right? So, keeping in mind this is a 30,000’ discussion, what’s at the cellular level, what kinds of characteristics stand out? Kimothy: Well, Klebsiella’s most immediate visual cue is its rod-shape and capsule. Its capsule is meant, in part, to protect it from hostile environments. Klebsiella thrives in the gastrointestinal tracts of a wide range of animals, including our own. And consequentially it’s also found in wastewater, soil, and then of course therefore, fruits and vegetables as well. Since it predominates these areas, it easily integrates into the water cycle and in particular municipal water networks. The capsules also promote biofilm development which allows it to better protect itself and easily persist in water distribution systems despite heavy chlorination. Like the other pathogens we’ve discussed this too is a gram-negative bacterium. And it’s non-motile, so it really depends on the biofilm for protection and nutrients. Christian: Biofilms keep coming up. I assume it’s not a coincidence that the CDC is emphasizing non-motile biofilm producers on its list of most concerning waterborne pathogens? Kimothy: Yes, that’s right, Christian. And I’ll just add that another common feature we’ll begin to see many of these bacteria share is the ability to resist antibiotics. Klebsiella is no exception. It is among the most resistant to antibacterial agents. Most recently to a class of antibiotics known as carbapenems. Christian: This is I suspect, in part, why we see so many healthcare-associated infections resulting from Klebsiella. Long-term care facilities, hospitals, clinics, and places where antibiotics are used, I imagine that’s why Klebsiella persists so much. So, tell me a little about the epidemiology. What kinds of illnesses are caused? Kimothy: So, I mentioned earlier that Klebsiella does exist in the human GI tract, but this does not cause disease. Klebsiella really only becomes a problem when it’s (like meningitis) transmitted in the blood or inhaled. So, serious blood infections and acute pneumonia are the biggest concerns. Particularly, patients needing long-term, recurring infusions or patients on ventilators are most susceptible. Also, individuals with liver disease and are hospitalized are known to get liver abscesses as a result of Klebsiella. Christian: Okay, so if I’ve got this right, I’ve got Klebsiella in my gut right now, but it’s essentially benign there because it really can’t take root and cause disease, but if it...
