Rare Bacteria Make Their Way to New York State

In late 2015, officials at the US Centers for Disease Control and Prevention (CDC) were alerted to the identification of a patient infected with Elizabethkingia anopheles in Wisconsin. By January 2016, 5 more cases had been reported, and by March 2016, the case count was up to 48.

The multidrug-resistant Gram-negative bacterium Elizabethkingia anopheles (E. anopheles) was discovered in the midgut of the Anopheles gambiae mosquito in 2011, according to an article in the February 2015 issue of Emerging Infectious Diseases. Symptoms of infection include fever, shortness of breath, chills, cellulitis.

This year, Rochester, New York, has seen their own share of cases, with 4 patients identified as being infected with Elizabethkingia bacteria between December 2017 and January 2018. Contagion^® sat down with Emil Lesho, DO, FACP, FIDSA, FSHEA, healthcare epidemiologist in the Infectious Diseases Unit at Rochester Regional Health in Rochester while at the SHEA 2018 Conference who explained more information about what makes Elizabethkingia unique (see video below).

According to Dr. Lesho, the challenge with Elizabethkingia is that clinical labs are unable to identify the pathogen to the species level. [The results will show] Elizabethkingia meningoseptica, but sometimes, the pathogen is really E. anopheles.

In the cases in Rochester, E. meningoseptica was isolated from the blood of 3 patients; however, further analysis through whole-genome sequencing (WGS) revealed that 2 of the patients infected with E. meningoseptica were, in fact, infected with E. anopheles, and 1 was positive for E. miricola. An additional case of E. anopheles was found in a “previously healthy 17-month-old infant [who was] admitted [to the hospital] for respiratory distress, fever, sepsis, and pneumonia,” according to Dr. Lesho. Unlike previous cases of the infection seen in infants, this infant had not had previous health care contact. The infant was treated with ampicillin and ceftriaxone for 2 days and after rapid improvement was discharged 4 days after admission.

Of note is that “there was some clinical concern as to whether the isolate was a contaminate, or whether it was a true bloodstream infection,” said Dr. Lesho, but this was found not to be the case.

Another case of E. anopheles was found from a culture taken from a 70-year-old female patient with chronic heart failure, metastatic cancer, and recurrent catheter-associated bacteremia who was dialysis dependent. The culture was taken on day 23 of admission. Bacteremia cleared and sepsis parameters normalized in the patient after approximately 2 to 3 days of treatment with minocycline and cefepime, which, according to Dr. Lesho, have been found to retain some activity against Elizabethkingia; however, the patient died of her comorbidities after discharge.

Neither of these patients had traveled outside of New York state. Both of the strains of E. anopheles found were “distinct strains separated by >500 single nucleotide polymorphisms (SNPs).” Furthermore, the E. anopheles isolated from the infant patient contained genes encoding resistance to extended-spectrum beta-lactams (blaCME-1), and carbapenems (blaB, _blaGOB-4). The infant’s isolate was closely related (80 to 90 SNPs) to an E. anopheles isolate from the Illinois cluster. Epidemiologic and genomic evidence from the New York cases did not support a common source.

The investigators believe that more cases are needed to determine if this represents a re-emergence of these bacteria or surveillance bias. “What we concluded is that, based on our experience, more reports like ours are needed in order to determine if they represent surveillance bias,” said Dr. Lesho. “We need those reports to determine whether it's just that we are better at detecting [these pathogens] and that we’re aware of the problem, or, it is really a re-emerging pathogen, that, based on what happened in Wisconsin, has the potential to harm people.”

Because clinical labs are not always capable of identifying the pathogen to the species level there could be more cases that are going undetected. Clinicians should be vigilant and if cases of E. meningoseptica are being picked up by their lab, they should consider sending those samples out to a reference lab. “Our mass spectroscopy (Vitek 2) misidentified all [the samples],” said Dr. Lesho; however, the lab technicians knew they needed to looked harder at the samples because they were current on the literature and alerts coming out of the CDC and state and local health departments. “Having a vigilant lab that works closely with the infectious disease team and the infection control team [helped us] not only with these Elizabethkingia cases, but also with the first case of Candida auris (outside the metropolitan area of New York City), which was found at our hospital,” shared Dr. Lesho (see video).

In terms of whether or not there should be concern that Elizabethkingia is going to become a new pathogen to worry about Dr. Lesho shared that, “the major studies that were published by the investigators that did WGS and mutation analysis of the Wisconsin outbreak strains concluded that the strain had the potential for rapid evolution and adaptability, and as a result, they called for ongoing surveillance.” However, he does not feel that there should be cause for panic or alarm. “If this was an outbreak,” he said, “we would be seeing more cases, by now.”