Salmonella, Turtles and Frogs...Oh My!
As many BioJobBlog readers may know by now, my PhD thesis focused on elucidating the underlying pathogenic mechanisms that contributed to the pathogenesis of Salmonella gastroenteritis. Salmonella gastroenteritis, which is primarily a food-borne illness, occurs in approximately 1.4 million Americans each year. Most people who develop Salmonella gastroenteritis recover without treatment within four to seven days. However, some people develop diarrhea so severe they are hospitalized and can become critically ill. According to a former lab mate, who accidentally infected himself, Salmonella gastroenteritis is much worse than the mild form of the disease described in many microbiology textbooks!
While I haven’t performed any research in this field for about 30 years, I still consider myself to be a Salmonella expert (go figure). Therefore, it should come as no surprise that a newspaper article entitled “Salmonella outbreak linked to pet frogs”— that appeared in the Salt Lake Tribune several weeks ago—caught my eye.
According to the article, a 31-state Salmonella outbreak (which was first detected in Utah was linked to pet frogs. The U.S. Centers for Disease Control and Prevention (CDC) in Atlanta started a national investigation to find the source of the outbreak this past summer, after five Utahans were infected by the strain of S. typhimurium a common cause of gastroenteritis (I knew getting a PhD would useful one day). In all, 85 people across several states developed gastroenteritis and nearly two-thirds had had some contact with frogs. Most of the patients were children and among those whose outcomes are known, almost a third required hospitalization. None died.
The source of the outbreak was eventually linked back to a single frog breeder in California that distributed the African dwarf frogs thought to be responsible for the multi-state outbreak. According to CDC officials, the bacteria were likely spread through contact with the tanks' water, not the frogs themselves. Of those who supplied information to the CDC, 30 percent said they cleaned the frog's aquarium in the kitchen sink and 35 percent used the bathroom basin.
While this last bit of information wasn’t remarkable, I finally—after almost 30 years as card carrying microbiologist—realized how the urban legend about Salmonella and turtles got started! Like many kids, I had a pet turtle. I remember my parents cautioning me about handling the turtle because I would get sick (of course I handled the turtle and never got sick). Later on, as a microbiology undergraduate student, I learned about the relationship between Salmonella and turtles and that turtle had been associated with Salmonella gastroenteritis outbreaks in the past. An interesting but inconsequential fact because I no longer owned a pet turtle.
Early on as a graduate student, I learned that it takes a minimum of about 108 salmonellae to cause gastroenteritis. At the time, I wasn’t thinking much about turtles and failed to realize that the large dose required for infection pretty much ruled out the likelihood that picking up a turtle would almost certainly result in Salmonella gastroenteritis. Although reptiles and amphibians harbor Salmonella in their gastrointestinal tracts, a child would have to suck on an infected turtle (or eat its poop) to get a large enough inoculum to initiate an infection—now this is where the PhD training become evident. However, if parents clean their children’s infected tanks in kitchen or bathroom sinks and then fail to wash their hands or the sinks with disinfectant, the number of salmonellae present in these environments would be sufficient to cause disease if infected food or water was ingested. And, this is what likely happened in the frog outbreak; based on the epidemiological data presented by CDC investigators
So, what is the lesson of this story? While it is true that turtles and frogs may carry Salmonella (in a separate study 21 percent of frogs from 16 retailers tested positive) the likelihood of developing gastroenteritis after touching or briefly handling frogs or turtles is extremely low. However, it is not a good idea to handle them for long periods of time without washing your hands before your next meal or cleaning their tanks in areas where food is prepared or people brush their teeth! Food borne illnesses are easy to prevent if appropriate personal hygiene is practiced and foods are prepared and cooked according to recommended standards.
Finally, it took a long time, but I can now feel comfortable around turtles. This is probably a good thing—my friend Pete is a turtle fanatic and he constantly wants me to pick up his pets!
Until next time...
Good Luck and Good Job Hunting!!!!!!!!!!

Johnson & Johnson
Late last week, the US Food and Drug Administration (FDA)
I have refrained from commenting on healthcare reform until now because there wasn’t much I could add to the debate. That said, while reading an article in a local paper on bacterial antibiotic resistance and how to minimize it, the author—an infectious disease doc—offered a telling statistic that identified the root problem with our current healthcare system. According to the article, 65% of the time, physicians will prescribe antibiotics to patients suffering from upper respiratory tract infections who demand them, whether or not they are warranted. In marked contrast, 12% of patients with upper respiratory tract infections who don’t ask for antibiotics receive antibiotic prescriptions. The bottom line: physicians give patients the drugs and treatment they demand because they are afraid of losing them as customers knowing full well the patients will go to another physician who will give them what they want! After all, physicians are in business and to stay in business they need to make enough money to cover their overhead and make a profit. However, over prescribing antibiotics is one of the main reasons why we are in the midst of an epidemic of infections caused by multiple drug resistant bacteria. In my opinion, business outcomes should never supersede or trump medical or public health outcomes.
Last week, I took a group of
The 2009 Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) is currently taking place in San Francisco. For those of you who may not know ICAAC, is an annual meeting mainly attended by infectious disease physicians and researchers where the latest and most cutting edge research on infectious agents is reported. Things must have been a little slow at this year’s meeting (except for H1N1 of course) which led the newswires to pick up a story about the isolation of
Vincent Racaniello, an intrepid virologist and
Rumors are rife that Novartis is going to purchase Lexington, MA-based Cubist for $1.6 billion. Wall Street analysts are speculating that Novartis may announce the deal as early as Monday.
That methicillin resistant Staphylococcus aureus (MRSA) is in the news again is not surprising. However, to my knowledge, Nicholas Kristof‘s article in today’s New York Times may be the first Op-Ed piece written by a non-scientist about the growing threat and seriousness of MRSA infections. Mr. Kristof apparently became aware of MRSA when he was contacted by Tom Anderson, MD, a Camden, Indiana physician who was experiencing “phenomenal levels of MRSA infections" in his community.
Targanta Therapeutics, a Cambridge, MA-based biopharmaceutical company, announced that it 
A Food and Drug Administration (FDA) advisory panel Thursday rejected a proposed antibiotic by Arpida Ltd. (ARPN.EB) to treat serious skin infections, a Food and Drug Administration spokeswoman said. The rejection was expected because results from Phase III clinical trials showed that patients taking iclaprim (a trimethoprim-like antibiotic) had lower cure rates than Pfizer's
A friend of mine accidentally gashed his leg on an open dishwasher door and thought nothing of it for several weeks until he noticed that the wound wasn’t healing and it hurt really badly. He eventually went to the emergency room at a local, where the ER docs cultured the wound and sent him home with a prescription for oral antibiotics. The antibiotics stopped working several days later and he wound up in another local hospital–this time he was admitted and the spent the next 5 days on a variety of intravenous antibiotics. Despite the treatment (they could not find the right antibiotic combination at first because they never recultured the wound) his leg turned black from his ankle to his knee and they almost had to amputate. He is back at home now and will be treated with a regimen of iv antibiotics for the next 6 weeks or so. I talked with him last week and I learned that his leg wound is still not completely healed and the infectious disease docs are worried!
Sinus infections are diagnosed in about 31 million Americans each year and are among the most common reasons for doctor visits. The infections affect the air spaces (sinuses) around the nose and in the lower forehead. Inflammation and excess mucous can cause nose congestion, headaches and eye and face pain. Causes include bacteria, viruses, fungal infections and allergies. 


