Klebsiella Pneumoniae

00:01 Klebsiella pneumoniae, a bacteria.

00:03 Klebsiella are gram-negative non-motile aerobic rods who have a very significant virulence promoting anti-phagocytic capsule on the outside.

00:15 The capsule is made out of multiple polysaccharides giving it a very mucoid appearance and you can see this on the image on the slide.

00:24 Mucoid, perhaps even slimy but in addition, these organisms are lactose positive, oxidase negative.

00:33 The beautiful thing is, the Klebsiella looks quite gorgeous on a typical McConkey eosin plate.

00:40 It looks purplish, sometimes even reddish or so.

00:43 So if one goes into beautiful images made by bacteria, Klebsiella is your friend.

00:49 The Klebsiellae are opportunistic pathogens, meaning that they exist in all of us, most often in our gastrointestinal tract.

00:58 And they only cause disease when they go someplace where they shouldn't.

01:02 Typically, via aspiration of the gastrointestinal material.

01:06 Now, that could be through vomitus that could be through a stool, it could be through fecal oral transmission.

01:14 But basically getting GI stuff into the mouth, into the airway or the blood stream is when the disease occurs.

01:22 The most at risk populations therefore are those who have some recent health compromise immunity.

01:29 Now, that could be a catheterized patient for example, somebody with an indwelling urinary tract catheter which limits mobility of immune system.

01:38 It can be those who are alcoholic who already have some suppressed immunity, but also are more likely to vomit while lying down and then to aspirate contents into their lungs.

01:49 Patients who have already compromised pulmonary or lung function, and of course diabetics.

01:56 Any of these are more likely to have Klebsiella growing from multiple, normally sterile sites.

02:02 So how does Klebsiella cause disease? Again, that prominent slimy or mucoid capsule which I mentioned before is very important in hindering phagocytosis.

02:13 In addition, as a gram-negative, it has lipopolysaccharides which trigger a pro-inflammatory cytokine response leading to virulence.

02:23 Aspiration of the Klebsiella is perhaps most likely way for disease to occur, again, getting some sort of GI material into the lungs.

02:32 When that happens, it most often causes a focal or a primary lobar pneumonia.

02:39 So, where might you see disease and where would you have specific types of disease? Well, again, those who are immunocompromised or those who've aspirated, and especially those who are at risk for developing pneumonia.

02:53 So those in nursing homes, perhaps the elderly, but also those with compromised lung function as mentioned before.

03:01 Urinary tract infections, these are the catheterized patients that we mentioned before, especially with long-term indwelling catheters.

03:09 Any of these focal infections, pneumonia or a urinary tract infection can develop a bacteremia, so circulating Klebsiella going throughout the blood stream, and when it develops into a progressive or an organized pneumonia, breakdown of alveolar and blood structures can occur leading to a current jelly or a bloody sputum.

03:33 Current jelly, if you've never seen it, search it.

03:35 It looks like dark, purplish jelly which when induced in sputum is not a good thing to see at all.

03:43 Cuz it represents a organized and very progressive pneumonia.

03:47 Diagnosis of Klebsiella is by its typical growth patterns, looking for presence of its urease which it has in abundance, looking for those shiny or mucoid slimy growth colonies which are pinkish to purplish in nature.

04:01 Importantly however, the image on the slide shows one of the important features of Klebsiella which is that it's very good at plasmid transfer of specific genes between organisms.

04:15 As you can see in the slide at the top, we have two organisms - two Klebsiella bacteria which may actually be linked in the process of division and the donor bacteria on the upper left has within it a plasmid derived gene or collection of genes.

04:33 It is able to transcribe and then process and share in the middle two bacteria that plasmid gene in that eventually, the bacteria separate and the recipient Klebsiella has now a fresh copy of that gene.

04:48 Why is this important? Because Klebsiella, like some other bacterium is very good at creating, maintaining and then growing antibiotic resistance typically through plasmid sharing of antibiotic resistance genes via those plasmid transfers.

05:07 So, that leads us to treatment of Klebsiella.

05:11 A typical initial antibiotic to start with would be a cephalosporin or a beta-lactam penicillin which is coupled with a beta-lactamase inhibitor. Klebsiellae most often contain at least one form of beta-lactamase.

05:27 And so they would be resistant to a traditional straightforward beta-lactam or a penicillin antibiotic.

05:34 But if one beta-lactamase inhibits that antibiotic, it may have more success.

05:39 However as mentioned before, Klebsiella are one of the enterobacteriaceae which is increasingly known to be resistant to cephalosporins and have multiple drug resistance genes contained within it via those plasmid transfers.

05:55 So Klebsiella, beautiful on culture plate, pink, shiny or slimy red colonies depending on how you like to look at it, present normally in the GI tract and typically not a problem until it enters into sterile space via aspiration into the lungs, into the urinary collecting system or into the bloodstream.

06:16 Then it is absolutely one of our biggest foes in terms of development of antibiotic resistance.