Are Antibacterial Soaps Effective?

The FDA is asking manufacturers to prove the effectiveness of their antibacterial products that use triclosan or triclocarban as the active ingredient. (See the press release here.) This comes on the heels of last week’s announcement of their plan to help phase out the use of medically important antibiotics in food animals.

When I became a microbiologist I stopped using products with triclosan in an effort to curb antibiotic resistance. While I like to see the FDA’s efforts, I wonder if they’re doing too little, too late, and I’m not the only one.

Some additional reading on the topic:

1. Mechanism of triclosan resistance study, published 1999.

2. Another triclosan resistance study, published 2006.

Edited to add: Maryn McKenna’s excellent write-up on the topic.

Swails

-Kelly Swails is a laboratory professional, recovering microbiologist, and web editor for Lab Medicine.

‘Tis the Season

The holiday season is rife with celebrations. Tree Trimmings! Presents! Gatherings! And let’s not forget the food. Turkey! Dressing (with or without oysters)! Cookies and its glorious dough! An unfortunate side effect of holiday celebrations is food poisoning, specifically those caused by, Salmonella, Campylobacter, and Vibrio.

According to the CDC, Salmonella and Campylobacter are in the top five pathogens with Salmonella being the biggest culprit in hospitalization. If you want to prevent Salmonella poisoning—or think you might already have it—here’s a handy guide to causes, symptoms, and treatment.

Raw eggs and mishandled poultry aren’t the only causes of food poisoning, though. Shellfish can be a concern, as is undercooked beef and unpasteurized dairy products. The Mayo Clinic has a wonderful chart describing the major food poisoning pathogens. A noticeable omission is Bacillus cereus, which breeds quite nicely in leftover rice.

For laboratory professionals, foodborne illnesses are a common cause of laboratory-acquired hospital infections. Be vigilant when handling enteric specimens and enteric cultures. Observe basic lab safety—use personal protective equipment, don’t use personal electronics in the lab, and be obsessive about washing your hands. Don’t let Salmonella or one of his buddies ruin your holiday season.

 

Swails

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

Dirty Winds

Over at Body Horrors, Rebecca Kreston writes about public health concerns of infectious disease and parasites. In this thought-provoking post, she discussions musicians (specifically, those who play wind instruments) and lung infections. She cites several small studies that found pathogens (Mycobacterium, Stenotrophomonas, and Cryptococcus) in instruments such as saxophones and trumpets.

The moral of the story: horn musicians, clean your instruments. And don’t ignore a persistent cough.

Swails

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

The Post-Antibiotic Era, Part 2

Linking to a few articles by Maryn McKenna because you need to read them.

In this blog post, Ms. McKenna writes about a man from New Zealand who died from a bacteria completely resistant to all antibiotics.

In this article, she imagines the post-antibiotic world. In a nutshell: it’s a scary place.

-Kelly Swails

 

 

A Possible Method to Diagnose Invasive Meningococcal Infection

Saying the word “meningitis” is a sure-fire way to scare parents of young children or college students. Invasive infections caused by Neisseria meningitidis are rare but serious. Mortality rates can run around 15%; complications include amputations due to tissue necrosis and hearing loss. In short, N. meningitidis infections are nothing to mess around with.

In order to avoid death and extremity loss, the infection needs to be diagnosed early. Trouble is, the early symptoms can be similar to those of a run-of-the-mill viral infection. Some patients do not exhibit the elevated white blood cell count so common in bacterial infections. Without clear signposts to guide the way, how can clinicians catch this fast-moving infection early in its course? A handful of esoteric hematology parameters might hold the key.

Demissie et al recently published this paper in The Pediatric Infectious Disease Journal about using neutrophil counts to diagnose meningococcal infection in children. It’s behind a paywall, but here’s the gist:

-Your automated hematology analyzer needs to report immature white blood cells.

-Using total white blood cell (WBC) counts or total neutrophil counts alone is insufficient.

-The parameters to check are absolute neutrophil count (ANC), immature neutrophil count (INC), and immature-to-total neutrophil ratio (ITR).

-Patients with invasive meningococcal infection (or, the authors also say, a serious bacterial infection) display abnormalities in at least one of the three parameters.

What do you think about these guidelines? Do you think they’d be effective in diagnosing invasive meningococcal infections?

-Kelly Swails

New Product Friday–Alifax SPA

Using light scattering technology to identify bacteria has been around for a few years (as evidenced by this paper from 2009 and this article from 2006. The methodology described in these articles use actual bacterial colony growth on conventional media for identification. This only shaves a day off turnaround time. This is handy, but can we do any better?

Enter Alifax SPA. They claim to have an automated analyzer capable detecting the presence of pathogenic bacteria, quantifying (in CFU/ml) that bacteria, and measuring the drug resistance of that organism in a few hours by using light scattering technology. Those techs that have worked in hematology or urinalysis are no stranger to this type of analyzer, but how well does it translate to the world of microbiology?

Does anyone have any experience with the HB&L or the Alfred 60? How do you feel about these analyzer? Do you like this much automation in the microbiology laboratory? Let us know in the comments.

-Kelly Swails

 

 

 

I’ll Have Pasteurized Milk, Please

Recently officials determined the cause of death of a young mother in Las Vegas: tuberculosis. The family Mycobacteriaceae contains several pathogenic species, including the most famous, M. tuberculosis. While none of the articles I read mention the species, they do mention the patient consumed unpasteurized dairy products, which leads me to believe she died of the zoonotic organism M. bovis.

Since these organisms are recovered infrequently, clinical microbiologists should brush up on the basics of these organisms on occasion. The CDC has some general information on Tuberculosis; the illustrious contributors at Wikipedia go a bit more in depth. The best sources for information are reference textbooks such as the Manual of Microbiology. It’s important to remember that mycobacteria can infect any region of the body, not just the respiratory system, so it’s important to keep an open mind. It’s also helpful to know that some species are rapid growers and may present on blood agar in a routine culture.

-Kelly Swails