microbiology – Page 34

Gut Flora and Chron’s Disease

I’m fascinated by the connection between gut flora and overall health. I just stumbled onto this article that discusses the connection between gut flora and Chron’s Disease. It’s based on this paper published in Cell. Recent articles about antibiotic’s role in obesity and papers on gut flora’s influence on the immune system keep raising the issue: how much do common organisms like E. coli, Clostridium perfringes, and Bacteroides fragilis affect us? How can we use them to diagnose, prevent, or cure disease? I’ll be keeping my eye on future research.

–Kelly Swails, MT(ASCP), is a laboratory professional, recovering microbiologist, and web editor for Lab Medicine.

Antibiotic Stewardship

The draft of the federal budget released Tuesday allocates $30 million dollars in CDC funding in order to combat antibiotic resistance. Obviously the 2015 budget isn’t finalized, but even so, it’s encouraging that the Department of Health and Human Services recognizes the need for antibiotic stewardship.

What is antibiotic stewardship, you ask? Basically, it’s a program within a healthcare community that dictates the best practices for prescribing antibiotics. Such programs would be tailored for each setting based on population demographics and antibiograms. Perhaps a program would prohibit prescribing, say, ciprofloxacin for urinary tract infections because a rise in the percentage of strains of E. coli resistant to fluoroquinolones has been noted. Maybe the program would discourage prescribing more than two antibiotics at once to a patient, or suggest antibiotics other than vancomycin (such as levoquin) when treating MRSA.

Creating a stewardship program requires input from several departments (Infectious Disease, Pharmacy, Epidemiology, and the Microbiology Laboratory) as well as acceptance by the clinician population at large. In my experience, this has been the limiting factor. Physicians don’t like being told what they can and can’t do for their patients or the insinuation that they might lack the proper knowledge about antimicrobials and microbiology to provide good patient care. This is a hurdle that hospitals will have to overcome in order to make stewardship programs a success. (Mentioning that such programs can save money and shorten hospital stays could help tip the scales.)

If you’d like to institute a stewardship program at your institution, here are a few links to get you started:

CDC’s Vital Signs about prescribing practices
Antibiotic management guidelines at John Hopkins
Professional practice resources from the Association for Professionals in Infection Control and Epidemiology
The ever-insightful Maryn McKenna over at Superbug discusses the topic at length

Does your institution have an antibiotic stewardship program? If so, what steps did you have to take in order to implement it?

–Kelly Swails, MT(ASCP), is a laboratory professional, recovering microbiologist, and web editor for Lab Medicine.

Vinegar to the Rescue

Can a common pantry staple kill bacteria? Possibly, according a paper recently published in mBio. Researchers mixed acetic acid–the main ingredient in white vinegar–with suspensions of bacterial cultures and found that a exposure times as little as 20 minutes reduced the viable bacterial population by 7¹⁰. The researchers then performed the same experiment, this time swapping out hydrochloric acid for the vinegar; they noted no bactericidal effect. Mycobacterium tuberculosis required a longer kill time (30 minutes vs. 20 minutes) to reach a 8¹⁰reduction in population.

These results suggest that vinegar could be used as a cheap-yet-effective disinfectant in resource-poor laboratory settings.

MALDI-TOF podcasts

Recently Dr. Nate Ledeboer from the University of Wisconsin talked with Lab Medicine about the clinical applications of MALDI-TOF in the clinical microbiology laboratory. The first podcast discusses anaerobic identification and the second discusses the identification of mycobacteria and fungi.

If you’re interested in listening to more Lab Medicine podcasts, you can find them here and here.

Want Some Wine With That?

The other day I read an interesting tidbit about acne bacteria found in grapevines. Propionibacterium acnes–an anaerobic gram-positive bacilli that lives on human skin and occasionally causes acne–was found in the bark and pith of grapevines in Italy. The researchers could have assumed the bacteria was a contaminant, but they didn’t. Inspired by Frank Zappa’s propensity for thinking outside the box, they delved a little deeper and realized this strain has been living on grapevines for thousands of years.

The best part? They named it Propionibacterium acnes type Zappae.

–Kelly Swails, MT(ASCP), is a laboratory professional, recovering microbiologist, and web editor for Lab Medicine.

Fecal Transplants and the Laboratory Professional

Fecal transplants are used to cure patients with stubborn C. difficile infections by repopulating their colons with normal flora. (If you want a refresher, check out Lab Medicine’s podcast on fecal transplants.) Ideally, family members of such patients donate the necessary stool, but that’s not always possible. Perhaps the family member has bowel issues themselves, or maybe they have an infectious disease that can be transmitted through stool. So what’s a patient to do? Thanks to companies like OpenBiome, they can use banked stool for their procedure.

The New York Times published an article about OpenBiome. The article touches on the FDA stance on this procedure and mentions that if this procedure is restricted, there is a risk of a black market. Fecal transplants are effective, after all, and the source material is free and easy to obtain. However, like anything done in the metaphorical back alley, there could be serious consequences (disease transmission comes to mind).

Fecal transplants aren’t going away, so if you work in micro they need to be on your radar. Perhaps making a fecal bank of sorts for your patients is an avenue worth exploring.

–Kelly Swails, MT(ASCP), is a laboratory professional, recovering microbiologist, and web editor for Lab Medicine.

To Test or Not to Test

Recently the editors of Lab Medicine received a request for information regarding referral of sensitivities from one site to another or to the same site within three days. Here are a few examples of what I mean so we’re all on the same page:

A pan-sensitive Staphylococcus aureus is recovered from a left ankle wound on 1/28; the same organism is recovered from the same site on 1/31.
An E. coli with a typical susceptibility pattern is recovered from a right knee incision on 2/3; the same organism is recovered from the right ankle on the same date.

Referring sensitivities can streamline processes; thereby saving time and money (for the lab as well as the patient). According to the CLSI guideline M100-S23 (January 2013), Enterobacter, Citrobacter, and Serratia may develop resistance within three to four days of treatment with third-generation cephalosporin; Staphylococcus spp. may develop resistance to during prolonged therapy with quinolones. Since resistance can develop over the course of the same disease occurrence, it’s advisable to retest the susceptibility after three days so therapy can be adjusted if needed.

As for referring one site to another—such a left ankle to a left knee—I couldn’t find any source that advocated this practice. However, I am aware of facilities that have implemented such policies. What policies does your microbiology department follow when referring one sensitivity result to another?

–Kelly Swails, MT(ASCP), is a laboratory professional, recovering microbiologist, and web editor for Lab Medicine.