E. Coli & azithomycin
- I know there are beneficial strains of E. coli (http://en.wikipedia.org/wiki/Escherichia_coli) that live in us all of the time, but I somehow got the impression that the nasty strains were transient and thus not likely to cause chronic diseases. I was wrong. Apparently there are people who are carriers of the nasty strains.I also assumed that the nasty strains could be killed with antibiotics. Apparently they are very difficult to kill. The article below describes a study in which azithromycin was used to treat 22 people. The azithromycin was given for weeks, much longer than you are likely to ever be treated with azithromycin.Neither the article nor the abstract (at bottom of the message) mentions what happened to the beneficial E. coli. Russ www.polymicrobial.com===============
One Antibiotic Appears to Ease Severe E. Coli InfectionSmall study looked at bacteria that caused German outbreakTuesday, March 13, 2012 Antibiotics E. Coli Infections
TUESDAY, March 13 (HealthDay News) -- Patients suffering from a strain of E. coli that produces Shiga toxin, which can be deadly, appear to respond to the antibiotic azithromycin (Zithromax), according to German researchers.
Starting in May 2011, an outbreak of Shiga-toxin-producing E. coli infected nearly 4,000 people in Germany, more than 800 of whom had confirmed cases of hemolytic uremic syndrome (HUS), which causes red blood cells to break apart, resulting in kidney failure.
Current treatment discourages using antibiotics for Shiga-toxin-producing E. coli because it could increase the risk for HUS, the researchers note.
"The successful decolonization of long-term carriers of the German outbreak strain is an important finding, as the legal authorities in many countries restrict long-term carriers in their social or working life," said lead researcher Dr. Johannes Knobloch, of the institute of medical microbiology and hygiene at the University of Lubeck. "However, decolonization by azithromycin should be investigated in further studies for other E. coli strains."
E. coli can cause persistent diarrhea, and it can be spread by those infected through person-to-person contact.
The German outbreak was a mix of E. coli strains O157 and O104 (or enteroaggregative E. coli), both investigated in the new study, which was published in the March 14 issue of the Journal of the American Medical Association. "For the treatment of one strain -- enteroaggregative E. coli -- azithromycin is one of the antibiotics of choice," Knobloch said.
The study reports on 65 infected patients -- some with HUS -- who were followed for almost 40 days after showing initial symptoms. Among these patients, 22 were treated with azithromycin starting almost 12 days after their symptoms began; the others were not.
Knobloch's team found that there were significantly fewer carriers of E. coli among those who took azithromycin, compared to those who didn't.
Twenty-one days after starting treatment, nearly 32 percent of those taking azithromycin still carried the bacteria, compared with almost 84 percent of those not treated, they found.
After about one month, only 4.5 percent of those who received azithromycin still had the bacteria, compared with more than 81 percent of those who were not treated, and at 35 days none of the patients in the treated group had the bacteria.
In addition, all the treated patients remained bacteria-free after two weeks of antibiotic treatment, the researchers noted. However, 25 of the 43 untreated patients still carried the bacteria 42 days after their symptoms started.
Based on the successful use of azithromycin, it was decided to provide the drug to the 15 patients who still had symptoms.
After receiving azithromycin treatment, these patients no longer carried the bacteria. Moreover, there were no signs of HUS among any of the patients who took the antibiotic, the researchers said.
"This is a small study, but since other antibiotics activate the Shiga toxin, this is a revealing study," said Dr. Marc Siegel, an associate professor of medicine at New York University in New York City. "Azithromycin may well be the preferred antibiotic when you suspect an aggressive E. coli or a toxic E. coli."
Another expert, Hugh Pennington, emeritus professor of bacteriology at the University of Aberdeen in Scotland, is more cautious.
This finding is "not surprising, but relevance to E. coli O157 is far from certain," he said. The O157 strain of E. coli is particularly severe and also produces the Shiga toxin that often leads to hemolytic uremic syndrome.
"Neither does it help much regarding the issue of antibiotic use increasing the frequency of hemolytic uremic syndrome caused by E. coli O157," Pennington said. "The issue here, of course, is not whether antibiotics help after hemolytic uremic syndrome has developed, but whether they help to induce it. The jury is still out."
SOURCES: Johannes Knobloch, M.D., department of medical microbiology and hygiene, University of Lubeck, Germany; Hugh Pennington, emeritus professor, bacteriology, University of Aberdeen, Scotland; Marc Siegel, M.D., associate professor, medicine, New York University, New York City; March 14, 2012, Journal of the American Medical Association=======================I'm pretty sure this is the abstract that goes with the article above. RussJAMA. 2012 Mar 14;307(10):1046-52.
Association between azithromycin therapy and duration of bacterial shedding among patients with Shiga toxin-producing enteroaggregative Escherichia coli O104:H4.Nitschke M, Sayk F, Härtel C, Roseland RT, Hauswaldt S, Steinhoff J, Fellermann K, Derad I, Wellhöner P, Büning J, Tiemer B, Katalinic A, Rupp J, Lehnert H, Solbach W, Knobloch JK.
Department of Internal Medicine I, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.
An outbreak of Shiga toxin-producing enteroaggregative Escherichia coli (STEC O104:H4) infection with a high incidence of hemolytic uremic syndrome (HUS) occurred in Germany in May 2011. Antibiotic treatment of STEC infection is discouraged because it might increase the risk of HUS development. However, antibiotic therapy is widely used to treat enteroaggregative E coli infection. In the German outbreak, a substantial number of patients received prophylactic azithromycin treatment as part of a therapeutic regimen with the C5 antibody eculizumab.
To analyze the duration of bacterial shedding in patients with STEC infection who did and did not receive oral azithromycin therapy.
DESIGN, SETTING, AND PATIENTS:
At a single center in Lübeck, Germany, 65 patients with STEC infection, including patients with HUS as well as STEC-infected outpatients without manifestation of HUS, were investigated between May 15 and July 26, 2011, and were monitored for a mean of 39.3 days after onset of clinical symptoms.
MAIN OUTCOME MEASURE:
Carriage of STEC after azithromycin therapy.
Twenty-two patients received oral azithromycin and 43 patients did not receive antibiotic treatment. Among antibiotic-treated patients, long-term STEC carriage (>28 days) was observed in 1 of 22 patients (4.5%; 95% CI, 0%-13.3%) compared with 35 of 43 patients (81.4%; 95% CI, 69.8%-93.0%) who were not treated with antibiotics (P < .001). All 22 patients receiving azithromycin treatment had at least 3 STEC-negative stool specimens after the completion of treatment, and no recurrence of STEC was observed in these patients. As proof of principle, 15 patients who initially were not treated with antibiotics and were long-term STEC carriers were treated with oral azithromycin given for 3 days and subsequently had negative stool specimens.
Treatment with azithromycin was associated with a lower frequency of long-term STEC O104:H4 carriage.
Abstract at: http://www.ncbi.nlm.nih.gov/pubmed/22416100