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Lit Review Feb #3

February 15, 2018

Disclaimer: this compilation of synopses have been collected from multiple sources, including Mark Crislip's Puscast, Journal Watch Infectious Diseases, Medscape Infectious Diseases, CDC MMWR, AMA Morning Rounds, ProMED Mail, Journal of Clinical Microbiology, Antimicrobial Agents and Chemotherapy, Clinical Infectious Diseases, and more. I chose these articles based on their relevance to clinical microbiology and would be of interest to my fellows, and some other pieces that I found amusing to read. All credit goes to these original contributors. I'm just a messenger :).

Spread of Meropenem-Resistant Streptococcus pneumoniae Serotype 15A-ST63 Clone in Japan, 2012–2014

  • 7-, 10-, and 13-valent pneumococcal conjugate vaccines (PCVs): decreased the total number of cases of invasive pneumococcal disease, but also a shift in serotype not covered by PCV

  • During 2012-2014 in Japan: emergence of strains of multidrug (penicillin, macrolide, and meropenem)–resistant pneumococcal serotype 15A and sequence type (ST) 63 (serotype 15A-ST63)

  • Resistance most likely due to recombination in pbp1a, which was identical to that in multidrug (including meropenem)–resistant serotype 19A-ST320 pneumococci, which have spread in the United States

The Clinical Utility of Methicillin Resistant Staphylococcus aureus (MRSA) Nasal Screening to Rule Out MRSA Pneumonia: A Diagnostic Meta-analysis with Antimicrobial Stewardship Implications

  • Current IDSA/ATS guidelines for treatment of HCAP/CAP pneumonia recommend empiric MRSA coverage in patients at risk (exposure to healthcare, previous antibiotic use, septic shock, etc) but prevalence of MRSA pneumonia is not high

  • Metaanalysis looking at 5,163 patients: MRSA nares screen had sens 70.9% and spec 90.3% for MRSA pneumonia of all types (CAP, HCAP, HAP, VAP)

    • When using prevalence of MRSA pneumonia of 10%: PPV 44.8%,NPV 96.5%

  • When looking only at CAP and HCAP: sens 85% spec 92.1%, respectively

    • PPV 56.8% and NPV 98.1%, respectively

  • When looking at VAP: sensitivity and PPV were low but specificity and NPV were still high (93.7% and 94.8%)

  • Nares screening for MRSA may be a good rule out test to predict MRSA pneumonia so people don’t have to get empirical treatment when they don’t need it

Prolonged Infusion Piperacillin-Tazobactam Decreases Mortality and Improves Outcomes in Severely Ill Patients: Results of a Systematic Review and Meta-Analysis

  • Time over MIC is important for action of beta lactams

  • Metaanalysis in >3000 patients: prolonged infusion associated with 1.46-fold lower odds of mortality, 1.77-fold higher odds of clinical cure, 1.22-fold higher odds of microbiological cure

Strongyloidiasis Outside Endemic Areas: Long-term Parasitological and Clinical Follow-up After Ivermectin Treatment

  • Rx is ivermectin but no strong evidence showing actual cure (absence of larvae by parasitological methods 1 year after treatment)

  • Study in Argentina in 71 patients with confirmed diagnosis, F/U for 4 years after treatment, looked at stool exam and PCR

  • PCR remained positive even at 4 years, most common manifestation is asymptomatic eosinophilia

Outbreak of Fluoroquinolone-Resistant Campylobacter jejuni Infections Associated with Raw Milk Consumption from a Herdshare Dairy — Colorado, 2016

  • Selling of raw milk is illegal in CO but…..

  • Herdsharing: members can purchase a share of a herd of cows or goats, and are entitled to a portion of raw milk – technically no “redistribution”

  • Identified 12 confirmed and five probable cases of Campylobacter jejuni infection among people in 171 households that drank raw milk from same herdshare

  • All isolates R to ciprofloxacin, tetracycline, and nalidixic acid

  • Dairy not closed since pasteurization (which is the only way to ensure safety) was not an option on site (if closed, there would be no way to re-openand retain safety)

    • Technically, dairy did not sell or redistribute raw milk

    • People are entitled to take their “share” of milk in its original form

    • They are encouraged to discard potentially affected milk and reminded that redistribution is illegal

Potential Confounding of Diagnosis of Rabies in Patients with Recent Receipt of Intravenous Immune Globulin

  • Basically, this article is a reminder that unvaccinated individuals who have received IVIG may test positive for rabies antibody without actually having rabies

Notes from the Field: Assessment of Rabies Exposure Risk Among Residents of a University Sorority House — Indiana, February 2017

  • Report of bat exposures at university sorority house

    • Bats had been routinely sighted in shared living areas and hallways, later learned that bats had been in at least one of the walls for 30 years

    • Risk assessment with abundance of caution identified and interviewed 140 students and 8 employees who resided or worked in the sorority house during the preceding 12 months

      • Based on longest report of incubation period from bat exposure (270 days)

    • A LOT of interviews: finally identified 4 people with highest risk (a bite, scratch, or direct skin contact), offered postexposure prophylaxis (PEP), which consists of human rabies immune globulin and a series of 4 doses of rabies vaccine

      • Two persons completed the PEP series

      • Two declined PEP because of a perceived lack of risk

Genomic Analysis of Hospital Plumbing Reveals Diverse Reservoir of Bacterial Plasmids Conferring Carbapenem Resistance

  • 2-year environmental surveillance at NIH Clinical Center: WGS of 108 isolates

  • All samples from ICU pipe wastewater and external manholes contained carbapenemase-producing organisms (CPOs) harboring blaKPC/blaNDM, suggesting a vast, resilient reservoir (the actual rate of infection with CPOs was still low and surveillance of HCWs did not show CPO. Phew!)

  • Evidence of common plasmid backbones in patients and environmental isolates, suggesting the presence of reservoir of mobile elements that may contribute to the spread of resistance genes

Origins of the current outbreak of multidrug-resistant malaria in southeast Asia: a retrospective genetic study

  • Standard Rx of P. falciparum in SEA: dihydroartemisinin–piperaquine

    • Combination of short and long acting drugs

    • Started to see Rx failures popping up, especially in western Cambodia

  • Analyzed genome sequence of 1492 P. falciparum from 11 locations across southeast Asia, including 464 samples collected in western Cambodia between 2007 and 2013

  • The resistant strains had KEL1/PLA1 co-lineage (each conferring R to each drug), which emerged in western Cambodia the same year that dihydroartemisinin–piperaquine became standard of treatment

    • Spread throughout region within the next 5 years

U.S. FDA Approves Gilead's Biktarvy Triple HIV Drug

  • New integrase inhibitor bictegravir with Descovy, an older medication that combines nucleoside reverse transcriptase inhibitors emtricitabine and tenofovir alafenamide

Olympics-IOC Discussing Norovirus Outbreak, More Cases Reported

  • A rise from initial 32 cases to 128 in less than one week (Tue-Thu) mostly among security guards, just ahead of Friday's opening ceremony in Pyeongchang and led to some 1,200 security staff being quarantined

  • Athletes not yet affected

Culture-independent discovery of the malacidins as calcium-dependent antibiotics with activity against multidrug-resistant Gram-positive pathogens

  • Calcium-dependent antibiotics (including DAP) are a small family of N-acylated cyclic peptides that require calcium for antibacterial activity

  • Known members contain conserved Asp-X-Asp-Gly

  • Biosynthesized by non-ribosomal peptide synthetases (NRPS) – NPRS adenylation site, which is conserved among these peptides could be used a