E. coli – It's Interesting

BR3GWM bacteria streaked and grows on an agar plate in the lab

by SARAH ZHANG

THE WOMAN HARBORING E. coli resistant to colistin did not know it, and it’s only luck that we do. Her doctor would have never prescribed that last-resort antibiotic for a routine urinary tract infection—it can cause serious kidney damage. But her doctor did take a urine sample, which ended up at the Walter Reed National Military Medical Center, where researchers had recently started testing for colistin resistance. The test came back positive. Then the came scary headlines about a new superbug in the US.

Superbugs are bacteria with genetic mutations that let them survive humanity’s harshest weapons in germ warfare: antibiotics. The gene behind this E. coli’s colistin resistance is called mcr-1. It first emerged last year when Chinese researchers found it in samples from hospital patients and raw pork. Why pork? Colistin’s serious side effects mean it’s no longer used as a human antibiotic in many countries. But in China, farmers have been adding it by the pound into feed to fatten animals up.

Once epidemiologists knew to look for mcr-1, they found it in Malaysia, England and then the rest of Europe. It was only a matter of time before colistin resistance turned up in the US. On the same day news came out about this woman’s colistin-resistant UTI, the Department of Health and Human Services also announced it found mcr-1 in a sample from a pig intestine.

Colistin is not used in animal feed in the US, so it’s unclear how colistin-resistant bacteria ended up infecting that woman—or that pig. But food and people move freely across borders. And more even seriously, US animal farmers do use other antibiotics—even human ones—on chicken, pigs, and cows. A growing body of research has linked antibiotic use in food animals to drug-resistant bouts of food poisoning from salmonella, campylobacter, and MRSA. Even more interesting is a possible link between antibiotics on meat and urinary tract infections, which science journalist Maryn McKenna has covered extensively. The Food and Drug Administration issued a guidance last year for farms to phase out medically important antibiotics, though only voluntarily.

The Rise of the Drug-Resistant UTI
Urinary tract infections are damn common—annoyingly common if you ask many women. And antibiotic resistant UTIs are on the rise, too: From 2000 to 2010, the number of UTIs resistant to the antibiotic Cipro went from 3 percent to 17.1 percent. Because UTIs afflict so many people, they’re fairly representative antibiotic resistance out there in people community—especially compared to the resistant infections that epidemiologists tend to study most intensely, like ones that kill already sick hospital patients. “UTIs are a good picture of what people are being exposed to on a daily basis” says Amee Manges, an epidemiologist at the University of British Columbia. Case in point: That colistin-resistant bacteria in the woman from Philadelphia.

Manges has spent the past fifteen years studying the link between antibiotic use in meat production, especially poultry, and UTIs. Back when she was working on her doctoral thesis at the University of California, Berkeley, she kept seeing young, otherwise healthy students with UTIs. Originally, she thought she was going to track sexual transmission of the E. coli that caused such infections. With that kind of sporadic sexual transmission, she should have seen many different strains. But when she DNA fingerprinted the bacteria, she found they were all the same strain—the same pattern you’d see from a single source, like if the campus cafeteria gave everyone food poisoning. She was never able to trace those UTI cases back to the original source, but she’s been working on the question ever since.

UTIs are so hard to trace because the infection might not set in until long after a patient first acquired to bacteria. Say a woman eats some undercooked chicken. “The bacteria just hangs out in your intestine for months or possibly years,” says Manges. Then you get risk factor for UTI—sex or a catheter insertion—and that bacteria makes its way from, ahem, the end of your gut to the urethra. But getting people to remember what they ate a week ago is hard. Getting people to remember what they ate a year ago? Hahaha.

The Surveillance Net
Nevertheless, Manges and others have found that strains on meat match strains found in UTIs. Because of the difficulty in tracing UTIs, that evidence is not as ironclad as the evidence for antibiotics use and antibiotic-resistant food poisoning. With routine surveillance of UTIs though, epidemiologists could get a better handle of not only resistant bacteria that come from meat—but also other sources like drinking water or travel or family members being in the hospital. But that surveillance doesn’t happen. “There’s no organized infrastructure to get a good handle about resistance rates across communities,” says Kalpana Gupta, an infectious disease specialist at Boston University.

When patients walk in with UTIs, doctors will often hand out antibiotics without doing a urine culture. Growing the bacteria takes two days—testing for antibiotic-resistance a third—and by that time the patient is usually on the mend already. The fact that the women in Philadelphia got tested was unusual. The fact that her sample was tested against colistin even more so. As Gupta says, “Colistin is not something we would even use to treat UTIs.” (Resistance to another class of antibiotics triggered that extra test in this case.)

The Centers for Disease Control and Prevention is now following up with the woman in Philadelphia to find out she ended up with that colistin-strain of E. coli, which has never been found in the US before. Her infection was fortunately not resistant to all antibiotics. But what makes the colistin-resistance gene mcr-1 so worrisome is that it’s on a small loop of DNA that different bacteria easily swap back and forth. Someday, another bacteria already immune to all other antibiotics will pick up mcr-1, too. It’s only a matter of time.

The wider the surveillance net though, the more quickly we’ll find it.

A 2015 report found that 60 percent of Americans report eating out at least once a week. Restaurant dining can be easy, enjoyable, even decadent — but are you prepared for the germs you may be exposed to along with your side of fries?

Here are eight things you should never touch at a restaurant.

The table

Charles Gerba, a professor of microbiology at the University of Arizona, found significant numbers of E. coli and coliform bacteria on restaurant tabletops — enough to present a danger to the public — particularly young children, the elderly, and people with compromised immune systems. And the bacteria numbers were even higher after the tables were wiped down, suggesting a direct connection between dirty rags and bacteria. The solution? Ask your server not to wipe your table before you sit down.

The menu

It’s hard to avoid touching a menu — which is probably why they’re some of the germiest things in any restaurant. Think about how many hands touch them on a daily basis, and how infrequently the menus are cleaned (or replaced). Also, restaurant staff may wipe down laminated menus with a rag. (Remember how filthy those are?)

A 2013 study found that menus are an ideal vehicle for different types of bacteria. E. coli can survive on a laminated menu for as long as 24 hours, and salmonella for as long as 72 hours. Donna Duberg, an assistant professor of clinical laboratory science from Saint Louis University, suggests paying attention to how your menu feels. “If there is visible food on the outside or if it feels ‘sticky,’” she tells Yahoo Health, “it is most likely harboring germs, bacteria, and viruses from everyone who has sat there or worked there over the last few days.” Be safe and give your hands a good wash after ordering (and before eating).

The ice in your drink

Like a cold drink? Restaurant ice makers aren’t cleaned nearly as often as they should be (ideally once a month), and may harbor bacteria. The bottom line? Ask for your soda without ice — your stomach will thank you.

The lemon and lime wedges in your drink

Whether you request it or not, restaurant drinks often come with a slice of lemon or lime. But a 2007 study found that 69.7 percent of lemon wedges tested showed some type of microbial growth — either on the rind or the flesh. Why? By the time it reaches your drink, that piece of fruit may have been handled by multiple people — plus, there’s no way to ensure proper handwashing practices have been followed. Although it won’t be as tasty, it’s wise to take that beverage straight up.

The ketchup bottle and salt and pepper shakers

“These are most likely never wiped off — and if they are, it is with a cloth that has been used to wipe off the table, chairs, trays, and has been ‘rinsed’ in a tub of dirty water,” Duberg says. Beyond that, it’s impossible to know who touched these before you (and whether they washed their hands). You’ve got your antibacterial wipes, right? If you need that ketchup, give the bottle a once-over before squeezing.

The tray

Just like the condiment bottles and menus, trays are rarely wiped down (and when they are, it’s with that same rag — yuck). Duberg suggests you avoid touching your tray as much as possible. “When eating in a fast-food establishment with trays,” she says, “I use hand sanitizer before touching my food, and never touch the tray after I sit down until after I am done eating.”

The buffet

Yes, buffets are as dirty as you thought they were. “It is a rare day when I will eat at a buffet or a salad bar,” Duberg says. “There are very few assurances that the food has been kept at the proper temperature (hot or cold); the remaining food from the container being replaced is often scooped into the container of fresh food, and the serving utensils are usually reused over and over again.” These latter two actions can carry bacteria, which have been multiplying all day, from one batch of food to the next. All you can eat? It may not be worth it.

The bathroom

It seems obvious, but the bathroom is often a reflection of how clean the rest of a restaurant is. Duberg suggests checking to see whether there’s a cleaning schedule posted on the door. “And use the sniff test,” she says. “If it smells dirty, it most likely is — wash your hands with lots of soap and water, dry with a paper towel, use the paper towel to open the door, and use hand sanitizer at the table before eating your food. Reminder: People who are not feeling well often go into the bathroom to vomit or have diarrhea, and may not wash their hands as well as I do.”

http://sarahwillettchang.tumblr.com/post/136132267031/8-things-you-should-never-touch-at-a-restaurant

Thanks to Pete Cuomo for bringing this to the It’s Interesting community.

It's Interesting

Tag: E. coli

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