It’s That Time of Year Again

It’s a few days after a major holiday (Memorial Day in the United States), and clinical microbiologists knows what that means. It’s foodborne illness season! According to the CDC, Norovirus and Salmonella are the biggest culprits, but several organisms can be implicated.

If your lab doesn’t recover Salmonella, Campylobacter, or E. coli O157:H7 often, consider brushing up on the identifying characteristics of these organisms. (Do you know which one doesn’t ferment sorbitol?) It’s also helpful to keep the patient history (in particular, their travel history) in mind when reading enteric cultures or performing a microscopic ova and parasite examination. Also, now is a good time to be sure your reporting procedures (including local public health contact information) are up to date.

Check out the CDC’s website for more information on foodborne outbreaks, including how many people are affected.

 

Swails

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

 

Your Microbiome and Your Health

The fine folks at Scientific American recently published a fascinating blog post about the diversity of one’s fecal bacteria. While it’s long been thought gut microbiomes can vary widely from day to day within the same person, the advent of direct-to-consumer microbiome testing has uncovered that variety can exist within the same specimen.

What? You’ve never heard of personal microbiome testing? Think of it as 23andMe for feces. Ubiome and American Gut provide this service for folks who aren’t squeamish about collecting their own stool swabs.

From the laboratory professional perspective, what do you think about this type of direct-to-consumer testing? Do you think testing a patient’s microbiome has a future in diagnostic or preventative medicine?

 

Swails

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

Antiobiotic Resistance Worldwide

The World Health Organization assessed worldwide antibacterial resistance and recently published their findings. The report notes that a post-antibiotic era isn’t a dystopian fantasy but, in fact, a real possibility in the 21st century. Dire? Yes, but if you’ve been following the news, unsurprising.

The press release is here.

You can download or order the report here.

You can read a summary of the report here.

 

 

Haemophilus influenzae Infections in Pregnant Women

The Journal of the American Medical Association recently published a paper about the association of invasive Haemophilus influenzae infections in pregnant women and fetal outcomes. The researchers studied British women who had an invasive H. influenzae infection (defined as recovery of said organism from a normally sterile site). The researchers concluded that pregnant women had a greater risk of invasive infection than non-pregnant women, and these infections resulted in poor pregnancy outcomes.
H. influenzae is a fastidious organism that grows on chocolate agar. Normally associated with respiratory infections, if the organism is an encapsulated strain, it can spread to other parts of the body and cause meningitis, septicemia, pericarditis, and even urinary tract infections.
In terms of identification, H. influenzae are small, gram-negative coccobacilli on microscopic examination. The opaque colonies appear grayish on chocolate agar. Because it requires X and V factors to grow, the organism will appear on blood agar only in the presence of an organism that hemolyzes the blood (like Staphylococcus aureus). In addition to the X and V requirements, H. influenzae ferments glucose and is catalase positive.

Want to learn more? The CDC has great information on this organism.

 

Swails

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

Antibacterial Resistance in Pediatric Patients

A recent paper in the Journal of the Pediatric Infectious Diseases Society discusses the rising rates of antibacterial resistance in pediatric patients. It’s an alarming (but not surprising) paper that serves as yet another call to action. Modern medicine is in jeopardy; my hope is that it’s not to late to stop the oncoming catastrophe.

As always, Maryn McKenna over at Superbug has an excellent write-up.

If you’d like to read the paper, it’s here.

 

Swails

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

 

Listeria monocytogenes

The FDA is currently reporting an outbreak of Listeria monocytogenes in some Hispanic-style cheeses. While Listeria isn’t listed in the top five pathogens that cause food poisoning, it’s number four on the list of foodborne pathogens that cause death. It also causes meningitis, encephalitis, and septicemia; in pregnant women, it can cross the placenta and cause abortion, stillbirth, or premature birth. Perhaps now would be a good time for a refresher course in this bacterium.

Listeria grows on blood agar; this growth can be enhanced by cold enrichment. Selective enrichment–inhibiting other organisms while bolstering the growth of Listeria–is recommended if the specimen is food or environmental in nature. Other characteristics include:

  • Short gram-positive rods
  • motile
  • Beta-hemolytic
  • Smooth, light gray, 1-2 mm colonies after 24-48 hours of incubation at 37 degrees C
  • Will grow at 4 degrees C
  • facilitative anaerobe
  • catalase positive
  • oxidase negative

Listeria can be hard to identify, not because it’s fastidious, but because it can be confused with organisms such as Group B Streptococcus, Erysipelothrix, and corynebacterium. Don’t let that happen to you!

 

Swails

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

 

 

 

 

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.

 

Swails

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