1307. The Mycoplasma Conundrum

Abstract Background Lockdown for Covid 19 between March 15 - 30, 2020 lead to sudden closures of schools, public gatherings, all but essential businesses, and stay-at-home orders. Between then and the end of April 2020, literally all enveloped respiratory viruses declined to virtually undetectable levels, suggesting a successful interruption of transmission. Weekly percentage positivity rates for M. pneumoniae and all other respiratory viruses from BioFire Syndromic Trends for weeks ending 3/7/2020- 4/24/2020. Weekly percentage positive rates are shown, with the Rhinovirus/Enterovirus rate divided by 3 and the M. pneumoniae rate multiplied by 10 to fit on the same scale. Methods We used the percentage positivity rates from BioFire Syndromic Trends and from GenMark Diagnostics to examine the post lockdown response of M. pneumoniae versus other respiratory viruses on the Respiratory Virus Panel (RP 2.0) Results As has been reported (Nawrocki J., et al, OFID 2021) and as shown in Figure 1, there was a rapid drop in the positivity rate for all enveloped respiratory viruses by 85.6% from an average rate of 2.014% positive for the week ending 3/14/20 to 0.29% for the week ending 4/18/20, while the positivity rate for M. pneumoniae actually increased by 44% from 0.536 % to 0.772%. The increase in M. pneumoniae positivity rate from its baseline of 0.51 ± 0.38 between 1/25/20 - 3/21/20 vs 0.71 ± 0.09 between 3/28/20 - 4/25/20 was significantly higher by t test, p=0.00574. Data from GenMark was available only monthly but also showed an upward rise from march to April, 2020. Conclusion It is well documented that M. pneumoniae is transmitted through respiratory mechanisms, yet lockdown measures sufficient to dramatically reduce ordinary respiratory virus transmission had no comparable effect on transmission of Mycoplasma pneumoniae. It is also well known that M. pneumoniae persists in the respiratory tract as long as months after an infection. Therefore, it is possible that this reservoir continued to be a source of transmission for M. pneumoniae, even though lockdown measures effectively interrupted the enveloped respiratory viruses. Disclosures Kenneth Rand, M.D., BioFire Diagnostics (Advisor or Review Panel member, Research Grant or Support)


Session: P-73. Respiratory Infections -Bacterial
Background. Pleural empyema from Streptococcus milleri (SM) is often complex and requires a combination of surgery and intravenous (IV) antibiotics. There is a paucity of data on the efficacy of oral (PO) treatment due to concerns about the development of resistance, particularly to fluoroquinolones (FQ). We report outcomes of postoperative antibiotic treatment for SM empyema over 3 years, including PO therapy.

Methods.
A single-center retrospective chart review was performed of 20 patients treated with video-assisted thoracoscopic surgery (VATS) from October 2015 to March 2018 and SM diagnosed by thoracentesis or operative culture. We reviewed clinical factors, route and duration of antibiotics, complications (empyema recurrence, repeat surgery, 30-day readmission due to empyema), and mortality (30day and 1-year) Results. Of the 20 patients, 12 (60%) received all IV and 8 (40%) transitioned to PO therapy (Table 1). Median age was 60 and 58 in the IV and PO group, respectively. IV treated patients had more comorbidities. Cultures were primarily monomicrobial. Isolates tested were susceptible (S) to penicillin (Table 1), Of 10 tested specimen, all had moxifloxacin MIC < 0.19 μg/mL and 8/8 specimens tested were S to levofloxacin. The average duration of antibiotic therapy in the IV group was 34 days and 32 days in the PO group. There were no complications in the IV group: however, there were 2 deaths (1 patient died from comorbid complications and 1 patient was readmitted and died due to MSSA endocarditis). There were no complications or deaths in patients treated PO.

Conclusion.
Our review suggests that early transition to PO antibiotics may be a viable option for operatively managed empyema caused by SM in certain patients. FQs have been generally avoided due to concerns about the rapid development of resistance that has been shown in-vitro; however, no in-vivo data have been reported regarding this concern. We show excellent outcomes with the use of PO therapy in susceptible isolates, particularly FQs, with no failure or reported resistance in patients with SM empyema treated with VATS. Further study is needed to validate these findings and determine optimal patient characteristics for transition to PO therapy.
Disclosures. Background. Lockdown for Covid 19 between March 15 -30, 2020 lead to sudden closures of schools, public gatherings, all but essential businesses, and stay-at-home orders. Between then and the end of April 2020, literally all enveloped respiratory viruses declined to virtually undetectable levels, suggesting a successful interruption of transmission. Weekly percentage positivity rates for M. pneumoniae and all other respiratory viruses from BioFire Syndromic Trends for weeks ending 3/7/2020-4/24/2020. Weekly percentage positive rates are shown, with the Rhinovirus/Enterovirus rate divided by 3 and the M. pneumoniae rate multiplied by 10 to fit on the same scale.
Methods. We used the percentage positivity rates from BioFire Syndromic Trends and from GenMark Diagnostics to examine the post lockdown response of M. pneumoniae versus other respiratory viruses on the Respiratory Virus Panel (RP 2.0) Results. As has been reported (Nawrocki J., et al, OFID 2021) and as shown in Figure 1, there was a rapid drop in the positivity rate for all enveloped respiratory viruses by 85.6% from an average rate of 2.014% positive for the week ending 3/14/20 to 0.29% for the week ending 4/18/20, while the positivity rate for M. pneumoniae actually increased by 44% from 0.536 % to 0.772%. The increase in M. pneumoniae positivity rate from its baseline of 0.51 ± 0.38 between 1/25/20 -3/21/20 vs 0.71 ± 0.09 between 3/28/20 -4/25/20 was significantly higher by t test, p=0.00574. Data from GenMark was available only monthly but also showed an upward rise from march to April, 2020.
Conclusion. It is well documented that M. pneumoniae is transmitted through respiratory mechanisms, yet lockdown measures sufficient to dramatically reduce ordinary respiratory virus transmission had no comparable effect on transmission of Mycoplasma pneumoniae. It is also well known that M. pneumoniae persists in the respiratory tract as long as months after an infection. Therefore, it is possible that this reservoir continued to be a source of transmission for M. pneumoniae, even though lockdown measures effectively interrupted the enveloped respiratory viruses.
Disclosures. Kenneth Rand, M.D., BioFire Diagnostics (Advisor or Review Panel member, Research Grant or Support)

Session: P-73. Respiratory Infections -Bacterial
Background. Cefiderocol (CFDC) is a novel siderophore-conjugated cephalosporin with broad activity against Gram-negative (GN) bacteria, including carbapenem-resistant isolates, and non-fermentative organisms. CFDC is approved by the FDA for complicated urinary tract infection (cUTI), hospital-acquired bacterial pneumonia, and ventilator-associated bacterial pneumonia. In this study, we analyzed the susceptibility of CFDC and comparators against aerobic nonfastidious GN isolates collected from US patients hospitalized with pneumonia (PHP) in 2020 as a part of the SENTRY Antimicrobial Surveillance Program.
Methods. A total of 1,877 Gram-negative isolates were consecutively collected from PHP in 27 US hospitals during 2020. Susceptibility (S) testing was performed using the CLSI broth microdilution method. CFDC was tested in iron-depleted Mueller-Hinton broth. CLSI or FDA (2021) breakpoints were used. Both CLSI and FDA (2021)  Conclusion. CFDC was highly active against US GN isolates from PHP, including CRE, XDR PSA and ABC, as well as SM. These in vitro results suggest that CFDC may be an important option for the treatment of PHP caused by GN organisms, particularly for pathogens which have few treatment options.