Stewardship / Resistance Scan for Jul 25, 2018

News brief

Study finds very low levels of antibiotics in leeches lead to resistance

Very low levels of antibiotics in the gut of leeches used in medicine are enough to promote antibiotic-resistant bacteria—and exposure to the leeches led to resistant infections in plastic surgery patients—an international group of researchers reported yesterday in mBio.

In 2011, plastic surgeons began reporting patients who had infections with Aeromonas bacteria resistant to the key antibiotic ciprofloxacin (Cipro). And at about the same time, University of Connecticut (UConn) microbiologist Joerg Graf, PhD, the senior author of the study, found that a strain of Aeromonas that usually thrives in leeches was not surviving well in their gut.

Graf and his team analyzed the medicinal leeches, which are used to reduce swelling in plastic surgery patients. They found, according to Graf, "Without ever having been in a hospital, without having seen a patient, these leeches contained Cipro-resistant bacteria." But the amount of antibiotic present in the leeches was extremely low, about 0.01 micrograms (mcg) per milliliter (mL), 400 times less than the concentration a bacteria must survive in order to be considered "resistant," according to a UConn news release.

The researchers traced the presence of the antibiotic to poultry blood on which the leeches had fed.

To determine whether such low levels of ciprofloxacin were truly causing antibiotic resistance, the scientists sequenced the genomes of Aeromonas from leeches contaminated with antibiotics. They found that they contained the three bits of DNA necessary for resistance to ciprofloxacin.

In addition, when the ciprofloxacin-resistant Aeromonas were grown alongside a test strain of Aeromonas in a clean lab medium or inside a leech, the test strain grew all over them. But if there was even a tiny bit of antibiotic added into the mix, as low as 0.01 mcg/mL, the ciprofloxacin-resistant strain dominated.
Jul 24 mBio study
Jul 24 UConn news release

 

CDC reports uptick in Candida auris cases

The United States now has 340 confirmed cases of Candida auris, according to an updated case count from the Centers for Disease Control and Prevention (CDC). While the total case count remains fairly low, it's risen by 29 since May and nearly doubled since November 2017.

As of Jun 30, infections by the multidrug-resistant fungus have been identified in healthcare facilities in 11 states, with most cases reported in New York (196), New Jersey (79), and Illinois (46). Cases have also been reported in Massachusetts (7), Florida (3), Maryland (3), Oklahoma (2), California (1), Connecticut (1), Indiana (1), and Texas (1). All cases represent laboratory-confirmed C auris infections, with an additional 29 cases are listed as probable, 22 of them in New Jersey.

The CDC also said that 643 patients have been found to be colonized with C auris, detected through targeted screening in four states reporting clinical cases. The screening is being conducted as part of an effort to control the spread of the pathogen, which can persist on surfaces in healthcare facilities and spread between patients.

In patients with compromised immune systems, C auris can cause serious invasive infections affecting the bloodstream, heart, brain, ear, and bones. More than 1 in 3 patients with invasive C auris infections die. The fungus, which was originally reported in Japan in 2009, has shown resistance to the three major classes of antifungal drugs used to treat Candida infections.

C auris cases have been reported in 30 countries.
Jul 23 CDC case count update

 

Study: Italian hospital surfaces harbor MCR-1 genes

A new study shows that 8.3% of tested surfaces in eight Italian hospitals harbor the MCR-1 gene, which confers resistance to colistin, an antibiotic of last resort. The research is published in Emerging Infectious Diseases.

Researchers conducted the study in an effort to establish the diffusion of the MCR-1 gene in healthcare settings. They collected 300 surface samples from the hospitals in 2016 and 2017, from the floor, bed footboard, and sink. A total of 25 (8.3%) of the samples had pathogens containing the MCR-1 gene.

"Identification results indicated that different species harbored the mcr-1 gene, including [Klebsiella] pneumoniae, K. oxytoca, [Escherichia] coli, Acinetobacter Iwoffii, Enterobacter cloacae, E. agglomerans, Citrobacter freundii, Pseudomonas aeruginosa, and P. putida. These results suggest that this gene is silently spreading to many gram-negative bacteria responsible for infections in the clinical settings," the authors said.

MCR-1-associated colistin resistance was first reported in Italy in 2015, in an Escherichia coli strain. The gene is found in approximately 10% of animal isolates and in 0.1% to 2% of human isolates globally, the authors wrote.

This study suggests hospital surfaces represent a possible reservoir of serious antibiotic-resistant nosocomial pathogens.
Jul 23 Emerg Infect Dis study  

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News Scan for Jul 25, 2018

News brief

Southern Hemisphere flu levels show mixed picture

The Southern Hemisphere's flu season, which typically lasts through October, shows mixed patterns, with activity that may have peaked in southern Africa, is increasing in South America, and is still below seasonal thresholds in Australia and New Zealand, the World Health Organization (WHO) said in its latest global flu update.

Most of the flu activity in southern Africa is from the 2009 H1N1 virus. In South America's temperate regions, flu activity has been reported in most countries, with H3N2 predominant in Chile and 2009 H1N1 predominant in Brazil, which is circulating alongside H3N2. In tropical countries in the Americas, flu activity varied, with hot spots including Guatemala and Honduras, where 2009 H1N1 is predominant, and elevated levels still reported in Colombia and Peru.

Though flu activity in Australia and New Zealand is still low, 2009 H1N1 is the most frequently detected flu virus.

In western Africa, influenza B from both lineages is predominant. In tropical parts of Asia, flu activity remained low except for Cambodia, where levels increased slightly.

Globally, influenza A made up 81.5% of detections for the week ending Jul 8. Of subtyped influenza A viruses, 80.7% were 2009 H1N1.
Jul 23 WHO global flu update

 

High-path avian flu outbreaks reported in Saudi Arabia, Russia

In the latest highly pathogenic avian influenza outbreak developments, Saudi Arabia detected H5N8 in poultry at a market in Riyadh and Russia reported 13 more H5 outbreaks, according to notifications from the World Organization for Animal Health (OIE).

Saudi Arabia's agriculture ministry said active surveillance on Jul 17 at the Alazizia bird market identified the virus in 1 of 20 ducks tested. All of the susceptible 14,675 birds at the location were destroyed to curb the spread of the virus, and authorities temporarily closed the market and applied other control measures. The country reported its last H5N8 outbreak in June, which involved a poultry farm in the city of Al Kharj in Riyadh province.

Of Russia's 13 H5 outbreaks, 12 are in the Republic of Tatarstan and 1 in Saratov Oblast, both in the west. The OIE report didn't list the subtype, but a recent report from the United Kingdom said the Russian outbreaks involve H5N8. The latest outbreaks are part of ongoing activity since the middle of June.

The outbreaks began from Jul 12 to Jul 20, and all occurred in backyard poultry. The virus killed 244 of 990 susceptible birds, and authorities culled the surviving ones as part of the steps to curb the spread of the virus.
Jul 24 OIE report on H5N8 in Saudi Arabia
Jul 25 OIE report on H5 in Russia

 

Chinese researchers describe rare thrombocytopenia syndrome

A study yesterday in The Lancet Infectious Diseases details the clinical and epidemiologic features of severe fever with thrombocytopenia syndrome (SFTS), an emerging infectious disease. The study describes a 16.2% case-fatality rate for the tick-borne infection.

Researchers conducted the prospective observational study at a hospital in Henan province, China, among lab-confirmed SFTS cases. From Apr 1, 2011, to Oct 31, 2017, a total of 2,096 cases were diagnosed. The mean age of patients was 61.4 years, and 59% of patients were female. The median time from symptom onset to hospital admission was 5 days, and the median duration of hospitalization was 8 days.

The case-fatality rate was 16.2%, and death was associated with males, older age, delay in diagnosis, and diarrhea. The development of hemorrhagic signs (adjusted odds ratio [OR], 2.79; 95% confidence interval [CI], 2.18-3.57; P < 0.0001) or neurologic symptoms (adjusted OR, 30.26; 95% CI, 21.39-42.81; P < 0.0001), were most strongly associated with fatal cases of SFTS.

SFTS, which is caused by a phlebovirus, was first recognized in China in 2009, and in South Korea and Japan in 2012.

In a commentary published alongside the study, Xue-Jie Yu, PhD, who was not involved in the study, writes that the clinical descriptions of SFTS support "that SFTS is a viral haemorrhagic fever, since the authors found a higher frequency of haemorrhagic signs than have been reported for Ebola virus disease or dengue."
Jul 24 Lancet Infect Dis study
Jul 24 Lancet Infect Dis commentary

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