Nocardia Research Articles

Nocardial Infection in the Early Period after Kidney Transplantation

Patients with solid organ transplant have weaker immune system and can develop opportunistic infections. Prophylactic antimicrobials can help lower that risk but do not prevent it completely. High index of suspicion increases the chance of diagnosing rare opportunistic infections in immunocompromised patients and helps early and effective treatment. We present a unique case of a patient who developed pneumonia from Nocardia early after kidney transplant despite being on trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis. He was diagnosed and treated early which helped improving his outcome. We discuss incidence, risk factors, and treatment of nocardiosis post kidney transplant.

Cutaneous Nocardiosis with Nocardia brasiliensis in an immunocompetent patient

Cutaneous Nocardiosis with Nocardia brasiliensis in an immunocompetent patient

Disseminated Nocardia infection in a patient with systemic lupus erythematosis

28 year old female who was under treatment for systemic lupus erythematosus with oral prednisolone for 4 months presented with history of fever with chills, productive sputum, pleuritic chest pain, exertional breathlessness, anorexia and was found to have signs of pneumonia clinically on the right side. She also gave history of gradual painful diminution of vision in her left eye and two episodes of generalized tonic clonic seizures just prior to admission. Despite empirical treatment with antibiotics, her condition gradually deteriorated. A computer tomography – thorax (HRCT), showed linear and nodular opacities in right middle lobe segments and right medial basal segment along with homogenous opacity with multiple cavitations noted in the lower lobe of right lung with air bronchogram. MRI- brain showed multiple conglomerate foci of ring enhancing lesions with moderate surrounding edema seen in bilateral cerebral hemispheres, irregular thickening of choroid seen in left eye with hyperintense vitreous cavity showing blooming. CSF did not show any abnormality. Nocardia farcinica was isolated from the vitreous. Diagnosis of Disseminated nocardiosis involving lungs, brain and left eye was made.

Real-World Use of Tedizolid Phosphate for 28 Days or More: A Case Series Describing Tolerability and Clinical Success.

Tedizolid has activity against Gram-positive pathogens as well as Mycobacterium spp and Nocardia spp. Real-world evidence supporting long-term tolerability and clinical success of tedizolid is lacking. Prolonged tedizolid therapy (median, 188 days; interquartile range, 62–493 days) appeared to be well tolerated in 37 patients (8.1% experienced adverse effect leading to discontinuation). Clinical success was 81.3% in those evaluated.

Primary cutaneous nocardiosis caused by a novel Nocardia species.

Primary cutaneous nocardiosis caused by a novel Nocardia species.

Clinical analysis of pulmonary nocardiosis associated with bronchiectasis

Objective: To better understand the clinical characteristics of pulmonary nocardiosis associated with bronchiectasis. Methods: Patients diagnosed as bronchiectasis complicated with pulmonary nocardiosis in 9 tertiary general hospitals in China were enrolled from March 2016 to March 2020, with the record of general data, imaging performance and pathogen. The literature was reviewed. Results: Totally 17 patients were included. There were 12 females and 5 males. The ages ranged from 45 to 79 years, with an average of (63±9) years. There were 15 nonsmokers and 2 smokers, all of whom with chronic course. The clinical manifestations were mostly cough, expectoration, hemoptysis, fever, and dyspnea. The imaging manifestation was bronchiectasis in both lungs, with the most common involvement in the left lower lung, right middle lobe and left lingual lobe. Sputum cultures were positive in 10 cases, bronchoalveolar lavage fluid (BALF) cultures were positive in 6 cases, and next generation gene sequencings were positive in 4 cases, including 2 cases of Nocardia gelsenkii, 2 cases of Nocardia abscess, 2 cases of Nocardia stellate, 1 case of Nocardia mexicana, 1 case of Nocardia otitis caviae, and 9 cases of undetermined Nocardia. There were 3 cases of Klebsiella pneumoniae, 2 cases of Pseudomonas aeruginosa and 2 cases of Aspergillus. The symptoms and imaging of all patients were improved after anti Nocardia therapy. Conclusions: Bronchiectasis combined with nocardiosis is more common in middle-aged and elderly women without smoking, which is similar to the clinical manifestations of Lady Windermere syndrome. Bronchiectasis often involves the left lower lobe, right middle lobe and left lingual lobe. Nocardia infection might further precipitate the initiation and progression of bronchiectasis.

Assessment of Microbiological Quality of Ready to Eat Food Served in Ships Along Warri, Koko and Port Harcourt Water Ways, Nigeria

Background: Food borne outbreaks have been associated with sourcing unsafe food. Therefore, the first preventative strategy should be to source safe food. Even if the sourced food is safe, measures need to be put in place to ensure that it remains safe during the transfer, storage, preparation and serving activities that follow. An understanding of the ship food supply and transfer chain will help to illustrate the points at which the food can become contaminated en route to the point of consumption. Objectives: The study was conducted in selected sea port in the core Niger Delta to assessed the microbiological quality of food served at different ship galley to crew and passengers and compered it to standard. Methods: Samples of food were taken from three (Port Harcourt Area one (PHSP), Warri (WSP) and Koko (KSP)) seaports within the South-South zone for laboratory analysis to uncover food spoilage microorganisms capable of causing disease outbreak among ship which could result to Trans border diseases. Eleven samples of different ready to eat food were collected from the locations, which included cooked rice; fried fish, irish potato porridge, vegetable soup, griki, pepper soup, fried irish potato, salad and bread were collected randomly. The samples were prepared and analyzed using standard procedures. Mean viable counts of aerobic and anaerobic bacteria were determined, ranging from (13×103cfu/g to 78×104 cfu/g) for ready to eat food. Results: Based on the finding KSP I, KSP J and KSP K food samples had the highest bacterial contamination on food while WSP F, WSP G and WSP H food samples had the least with the following isolates Salmonella spp, Nocardia spp, Shigella spp, Listeria spp, Bacillus cereus, Leuconostoc spp, Acinetobacter spp, Acetobacter spp, campylobacter spp, Clostridium spp and Vibrio spp which revealed that the isolates were susceptible to any of these antibiotics Septrin, Chloramphenicol, Gentamycin, Tarvid, Streptomycin, Reflacin, Augumetin, Ceporex, Nalidixic acid, Ampicillin, Ciproflox, Penicillin and Erythromycin. Conclusion: Thus, ships operators and regulatory body are expected to take all practicable measures to ensure that they do not receive unsafe or unsuitable food and maintain adequate food temperature at all time.

Observational study of the clinical utility of sulfamethoxazole serum level monitoring in the treatment of brain abscesses due to Nocardia species.

Although there is a lack of data in trimethoprim-sulfamethoxazole (TMP-SMX) serum monitoring utility for invasive nocardial infections, therapeutic drug monitoring is widely used to optimize dosing and avoid adverse reactions that may cause treatment interruption.We retrospectively reviewed all adults who received TMP-SMX to treat nocardial brain abscess and had SMX serum level testing from 2010 to 2020.Twenty-two patients received treatment with TMP-SMX for Nocardia species brain abscess and 16 (72.7%) had a reported SMX level, with a median patient age of 65.5 years (interquartile range, IQR 59.5–72.5). Compared to those who did not have a documented SMX serum level, patients with SMX levels had a shorter median course of TMP-SMX treatment (322 days [IQR 188–365] vs. 365 [IQR 224–365]; P = .31) and higher therapeutic induction dose (10 [62.5%] vs. 3 [50%]; P = .92). Similarly, they were more frequently on hemodialysis (3 [13.6%] vs. 1 [4.5%]; P = > .99). The median peak level was 158.5 (IQR 120–218) μg/mL, collected at 2 hours (75%) post-administration in the induction phase (81.3%). Patients with documented SMX levels had fewer reported drug toxicity (5 [31.3%] vs. 4 [66.7%]; P = .1) than those without SMX levels. Among the five patients who reported TMP-SMX-related toxicity, 4 (80%) had an SMX peak level >150 μg/mL. There was no difference in the cure, relapse, and death rates among the two groups.While SMX level was not associated with Nocardia species brain abscess cure rates and mortality, most patients with SMX peak >150 μg/mL experienced drug toxicity.

Estradiol Aggravate Nocardia farcinica Infections in Mice.

Males are generally more susceptible to Nocardia infection than females, with a male-to-female ratio of 2 and higher clinical disease. 17β-Estradiol has been implicated in affecting the sex-based gap by inhibiting the growth of N. brasiliensis in experiments, but the underlying mechanisms have not yet been fully clarified. In the present study, however, we report increased severity in N. farcinica IFM 10152-infected female mice compared with male mice with increased mortality, elevated lung bacterial loads and an exaggerated pulmonary inflammatory response, which was mimicked in ovariectomized female mice supplemented with E2. Similarly, the overwhelming increase in bacterial loads was also evident in E2-treated host cells, which were associated with downregulating the phosphorylation level of the MAPK pathway by binding the estrogen receptor. We conclude that although there are more clinical cases of Nocardia infection in males, estrogen promotes the survival of the bacteria, which leads to aggravated inflammation in females. Our data emphasize the need to include and separately analyze both sexes in future studies of Nocardia to understand the sex differences in immune responses and disease pathogenesis.

Fast or slow: Diagnostic challenges in ocular and cerebral nocardiosis

Manifestations of Nocardia infections are diverse due to the ability of the organism to disseminate to almost any organ.1 Cerebral infection is not uncommon, particularly with Nocardia paucivorans,2 but ocular disease is rare.3

A Case of Nocardiosis with an Unusual Presentation

Nocardiosis is a neglected, unusual disease caused by aerobic, gram positive, actinomycete in the genus Nocardia. Nocardial infection most often occurs in immunocompromised patients. It has varied geographical distribution and a range of clinical presentations. Lungs are the primary sites of nocardial infection in more than two-third of cases. We report a case from a tertiary care setup in Karachi where nocardiosis occurred in an immunocompetent patient with an isolated CNS involvement.

Isolation and Characterization of Nocardia Species from Pulmonary Nocardiosis in a Tertiary Hospital in China.

This study aimed to investigate the clinical features, distribution, and antimicrobial susceptibility of Nocardia species isolated from pulmonary nocardiosis cases in a tertiary hospital in China. The species were collected from January 1, 2018, to May 31, 2019, and identified using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry or polymerase chain reaction. Antimicrobial susceptibility testing was performed using the broth microdilution method. Within the 44 Nocardia species, N. farcinica was the most frequently identified species (n = 36), followed by N. nova (n = 5), N. otitidiscaviarum (n = 1), N. cyriacigeorgica (n = 1), and N. transvalensis (n = 1). The top 3 predisposing factors of pulmonary nocardiosis were chronic obstructive pulmonary disease (45.5%), hypertension (34.1%), and tuberculosis (31.8%). All 44 Nocardia species were susceptible to amikacin, trimethoprim/sulfamethoxazole, and linezolid. The resistance rates of Nocardia to amoxicillin-clavulanic acid, ciprofloxacin, clarithromycin, ceftriaxone, tobramycin, and imipenem were 4.5%, 9.1%, 79.5%, 72.7%, 63.6%, and 38.6%, respectively. Two Nocardia strains had decreased sensitivity to trimethoprim/sulfamethoxazole. In conclusion, N. farcinica was the most frequently isolated Nocardia species in the First Hospital of Changsha. All the isolated clinical Nocardia species showed susceptibility to amikacin, trimethoprim/sulfamethoxazole, and linezolid, suggesting that these drugs can be primary therapeutic choices for treating Nocardia infections.

Nocardia Infection in Nephrotic Syndrome Patients: Three Case Studies and A Systematic Literature Review.

ObjectiveThe multicenter literature review and case studies of 3 patients were undertaken to provide an updated understanding of nocardiosis, an opportunistic bacterial infection affecting immunosuppressed nephrotic syndrome (NS) patients receiving long-term glucocorticoid and immunosuppressant treatment. The results provided clinical and microbiological data to assist physicians in managing nocardiosis patients.MethodsThree cases between 2017 and 2018 from a single center were reported. Additionally, a systematic review of multicenter cases described in the NCBI PubMed, Web of Science, and Embase in English between January 1, 2001 and May 10, 2021 was conducted.ResultsThis study described three cases of Nocardia infection in NS patients. The systematic literature review identified 24 cases with sufficient individual patient data. A total of 27 cases extracted from the literature review showed that most patients were > 50 years of age and 70.4% were male. Furthermore, the glucocorticoid or corticosteroid mean dose was 30.9 ± 13.7 mg per day. The average time between hormone therapy and Nocardia infection was 8.5 ± 9.7 months. Pulmonary (85.2%) and skin (44.4%) infections were the most common manifestations in NS patients, with disseminated infections in 77.8% of patients. Nodule/masses and consolidations were the major radiological manifestations. Most patients showed elevated inflammatory biomarkers levels, including white blood cell counts, neutrophils percentage, and C-reactive protein. Twenty-five patients received trimethoprim-sulfamethoxazole monotherapy (18.5%) or trimethoprim-sulfamethoxazole-based multidrug therapy (74.1%), and the remaining two patients (7.4%) received biapenem monotherapy. All patients, except the two who were lost to follow-up, survived without relapse after antibiotic therapy.ConclusionsNephrotic syndrome patients are at high risk of Nocardia infection even if receiving low-dose glucocorticoid during the maintenance therapy. The most common manifestations of nocardiosis in NS patients include abnormal lungs revealing nodules and consolidations, skin and subcutaneous abscesses. The NS patients have a high rate of disseminated and cutaneous infections but a low mortality rate. Accurate and prompt microbiological diagnosis is critical for early treatment, besides the combination of appropriate antibiotic therapy and surgical drainage when needed for an improved prognosis.

Detection of Nocardia by 16S Ribosomal RNA Gene PCR and Metagenomic Next-Generation Sequencing (mNGS).

In this study, the aim was to investigate the discriminatory power of molecular diagnostics based on mNGS and traditional 16S ribosomal RNA PCR among Nocardia species. A total of fourteen clinical isolates from patients with positive Nocardia cultures and clinical evidence were included between January 2017 and June 2020 in HeNan Provincial People’s Hospital. DNA extraction and 16S rRNA PCR were performed on positive cultures, and pathogens were detected by mNGS in these same samples directly. Among the 14 Nocardia isolates, four species were identified, and N. cyriacigeorgica (8 cases) is the most common species. Twelve of the 14 Nocardia spp. isolates were identified by the two methods, while two strains of N. cyriacigeorgica were not identified by mNGS. All tested isolates showed susceptibility to trimethoprim-sulfamethoxazole (SXT), amikacin and linezolid. Apart from Nocardia species, other pathogens such as Acinetobacter baumannii, Klebsiella pneumonia, Aspergillus, Enterococcus faecalis, Human herpesvirus, etc., were detected from the same clinical samples by mNGS. However, these different pathogens were considered as colonization or contamination. We found that it is essential to accurately identify species for determining antibiotic sensitivity and, consequently, choosing antibiotic treatment. 16S rRNA PCR was useful for identification of nocardial infection among species, while this technique needs the clinicians to make the pre-considerations of nocardiosis. However, mNGS may be a putative tool for rapid and accurate detection and identification of Nocardia, beneficial for applications of antimicrobial drugs and timely adjustments of medication.

Atypical presentation of an uncommon pathogen

Establishing a definitive diagnosis of Nocardia infection can be challenging due to its rarity, its diverse clinical presentation and the limitations in cultivating this microorganism. Only two cases of laryngeal nocardiosis have previously been reported, both in immunocompromised patients. We describe the case of a 67-year-old seemingly immunocompetent wildlife photographer, with an extensive travel history to Asia and Central America, who presented with an 8 month history of hoarse voice and odynophagia. An initial CT had revealed the presence of a laryngeal “mass” suggestive of malignancy, but several biopsies showed granulomatous inflammation. These were not sent for microbiological investigation. Empirical high dose steroids -started due to concerns of airway compromise- did not significantly improve his symptoms. Further laryngeal biopsies led to the isolation of a fungal mold (Chaetomium spp) of uncertain relevance. Voriconazole was initiated but not tolerated. A repeat biopsy was arranged: Fungal cultures were negative, however histological examination revealed branching gram positive bacteria. Nocardia spp was isolated on mycobacterial culture media and confirmed by PCR. Speciation was inconclusive. Co-trimoxazole was continued for 6 months with good clinical and radiological response. Treatment was discontinued at the patient's request, but within two months he relapsed with worsening dysphagia and odynophagia accompanied by weight loss. He was found to have developed a further post-cricoid collection with associated necrosis. Co-trimoxazole was restarted for 12 months followed by life-long secondary prophylaxis. He remains well with no further recrudescence. This case illustrates the many challenges in the diagnosis and treatment of nocardiosis. Abstract without diagnosis Establishing a definitive diagnosis of infection with this microorganism can be challenging due to its rarity, its diverse clinical presentation and the limitations in cultivating it. Only two cases of laryngeal infection have previously been reported, both in immunocompromised patients. We describe the case of a 67-year-old seemingly immunocompetent wildlife photographer, with an extensive travel history to Asia and Central America, who presented with an 8 month history of hoarse voice and odynophagia. An initial CT had revealed the presence of a laryngeal “mass” suggestive of malignancy, but several biopsies showed granulomatous inflammation. These were not sent for microbiological investigation. Empirical high dose steroids -started due to concerns of airway compromise- did not significantly improve his symptoms. Further laryngeal biopsies led to the isolation of a fungal mold (Chaetomium spp) of uncertain relevance. Voriconazole was initiated but not tolerated. A repeat biopsy was arranged: Fungal cultures were negative, however histological examination revealed a pathogen through Gram stain. This microorganism was further isolated on mycobacterial culture media and confirmed by PCR. Speciation was inconclusive. Tailored treatment was continued for 6 months with good clinical and radiological response. Treatment was discontinued at the patient's request, but within two months he relapsed with worsening dysphagia and odynophagia accompanied by weight loss. He was found to have developed a further post-cricoid collection with associated necrosis. Once he completed 12 months of treatment, life-long secondary prophylaxis ensued. He remains well with no further recrudescence.

Nocardia farcinica as a Cause of Complicated Chronic Suppurative Otitis Media: A Case Report

Nocardia belongs to the order Actinomycetales suborder Corynebacteriaceae, family Nocardiaceae. It causes infections mostly in immunocompromised individuals. It primarily causes pulmonary infections, followed by central nervous system infections, cutaneous and disseminated infections. Cutaneous infections are reported in immunocompetent individuals also. Because of the growth characteristics, it is difficult to recover the organisms in culture. The recent advanced molecular technology has made identification of the organism to species level possible. Chronic Suppurative Otitis Media (CSOM) due to Nocardia spp is rarely reported. Here, authors report a case of CSOM caused by Nocardia farcinica in a 47-year-old female. The patient was on steroid therapy for bronchial asthma. Culture of ear discharge isolated Nocardia spp, identified as Nocardia farcinica by mass spectrometry. Appropriate antibiotic treatment was administered and good treatment response was obtained. Early diagnosis and appropriate antibiotic treatment is critical for nocardial infections. Difficulty in recovering and identifying the organism, with delay in initiating appropriate treatment can result in poor prognosis and treatment failure.

A ten-year retrospective analysis of nocardiosis in a tertiary care center of South-coastal India.

Nocardiosis is an uncommon life-threatening infection caused by Nocardia spp. This study aimed to review the distribution of risk factors, clinical characteristics, microbiological findings, treatment and outcome of patients diagnosed with nocardiosis. This study was a retrospective case record review of all nocardiosis cases that were diagnosed at our tertiary care hospital from January 2008 to December 2019. A total of 48 patients with a mean age of 52.2±16.28 years were included. Out of which forty one (85%) were diagnosed as pulmonary nocardiosis and seven (14.6%) as disseminated disease. Chronic lung disease 25 (52.1%), long term steroid use 22 (45.8%) followed by diabetes mellitus 11 (22.9%) were common predisposing factors. The common symptoms were fever (87.5%), cough (79.2%) and breathlessness (52.1%). The most frequent radiologic finding included consolidation in 38 (79.1%), cavitation with thickened wall in 2 (4.1%), reticulonodular shadows in 2 (4.1%), and unilateral pleural effusion in 5 (10.4%). Nocardia otitidiscaviarum (22.9%) was frequently isolated from cultures. Resistance to trimethoprim-sulfamethoxazole (TMP-SMX) was observed in 21% cases. Mortality was noted in 6 (12.5%) patients and all were with pulmonary involvement. The percentage of death among those with and without pulmonary tuberculosis was 33.3% and 5% respectively. Patients affected by pulmonary nocardiosis with previous history of pulmonary tuberculosis showed significant association with poor outcome (p-value=0.05). In conclusion, nocardiosis mainly affects patients with structural lung disease or immunocompromised hosts with adverse outcome. Awareness of this infection is crucial for a clinician, and any suspicion should lead to make an early diagnosis and choose an appropriate empirical treatment to improve the outcome in this population.

1233. Serious Toxicities During Antimicrobial Therapy for Disseminated Nocardia Infection in Solid Organ Transplant Recipients

BackgroundManagement of disseminated Nocardia (NC) infection in transplant recipients requires prolonged antimicrobial therapy. Treatment can be particularly challenging if NC is resistant to standard agents. Drug toxicities can further limit options. We present a series of transplant patients with multi-drug resistant, disseminated NC infection complicated by serious adverse reactions to sequential antimicrobials.MethodsThis is a prospective review monitoring response to treatment of disseminated NC as well as adverse events to therapies. ResultsThe first case is a 66-year old heart transplant patient who presented with fever and cough. Investigations revealed N. otitidiscaviarum lung lesion and multiple brain abscesses. Trimethoprim-sulfamethoxazole (TMP-SMX) and linezolid were started empirically. NC was fully susceptible to linezolid only, and intermediate to quinolones and tobramycin. Linezolid was switched to ciprofloxacin due to ongoing cytopenia, and dose of TMP-SMX was reduced due to renal insufficiency. Repeat brain MRI showed enlarging abscesses; regimen was changed to linezolid and moxifloxacin. Severe peripheral neuropathy led to linezolid discontinuation and initiation of high-dose doxycycline plus moxifloxacin. One year into therapy, he presented with a large aortic dissection. His long-term quinolone therapy was felt to be contributory. He underwent aortic stent placement and remains on doxycycline monotherapy. The second case is a 74-year old female renal transplant patient who presented with fevers. A perinephric abscess was found which grew N. farcinica resistant to floroquinolones and clarithromycin, and intermediate to doxycycline. Further imaging also revealed pulmonary and brain involvement. TMP-SMX was started but soon switched to linezolid due to acute kidney injury. One month later she presented with severe thrombocytopenia and subdural hematoma thought to be secondary to linezolid. She died despite surgery. ConclusionThis series illustrates challenges encountered in the treatment of disseminated NC infection in transplant recipients. Multidrug resistant NC coupled with serious toxicities of therapies often severely limits treatment options. Counseling patients and closely monitoring for adverse events is essential. Disclosures All Authors: No reported disclosures

272. Clinical Utility of Sulfamethoxazole Serum Level Monitoring in the Treatment of Brain Abscesses due to Nocardia Species

Abstract Background Although trimethoprim-sulfamethoxazole (TMP-SMX) has consistently demonstrated significant interindividual variability, therapeutic drug monitoring is used to optimize dosing and avoid adverse reactions that may contribute to treatment interruption. While data exists on the use of SMX level monitoring in pneumocystis, there is a lack of data in SMX serum monitoring utility for invasive Nocardia infections. Methods We retrospectively reviewed adults who received TMP-SMX to treat nocardial brain abscess (BA) and underwent SMX testing level from January 2010 to December 2020. Results Overall, 24 patients had Nocardia spp. BA; Twenty-two (91.7%) were treated with TMP-SMX, and 16/22 (72.7%) had a documented SMX serum level. The median age was 64 (IQR 58-69) years, and the majority were males (77.3%). Compared to those who did not have a documented SMX serum level, patients with SMX levels had a higher prevalence of hemodialysis (HD, 42.9% vs. 33%; P=.99) and malignancy (50% vs. 33.3%; P=.65). The most common BA location was the frontal lobe (43.8% vs. 33.3%; P=.99), with a single (68.8% vs. 50%; P=.62) and smaller (1.3 vs. 1.9 cm; P=.58) brain fluid collection, and with fewer midline shift (6.3% vs. 16.7%; P=.48), respectively. The median TMP-SMX duration was 350 days (P=.31). The most common dosing was 2-double strength, three times a day (31.8%). The SMX median level was 158.5 (IQR 120-218) mcg/mL, collected at two hours (75%) post-administration in the induction phase (81.3%). The most common recommendation was to continue therapy based on the level results. Eleven (46%) patients had a level >150 mcg/mL, and 5 (45.5%) reported drug toxicity, including nausea in 3, acute kidney injury in 2, and thrombocytopenia in 2 patients. Ninety-four percent of the patients with SMX levels had surgical intervention for therapeutic purposes vs. 83% of those without it (P=.65). A total of 11 (50%) patients were cured, 3 (18.8%) relapsed, and 2 (12.5%) died. Conclusion Patients with SMX serum level monitoring are more likely to be on HD, during the induction phase and among those with higher and more frequent dosing. About half of patients with SMX levels >150 mcg/mL experienced drug toxicity; however, SMX levels did not impact patient outcome and length of treatment. Disclosures All Authors: No reported disclosures

947. Nocardiosis in Renal Transplant Recipients Linked to Decreased Utilization of Trimethoprim/Sulfamethoxazole During COVID-19

BackgroundThe renal transplant population is at increased risk of Nocardiosis due to impaired T-cell mediated immunity with immunosuppression. Pneumocystis jirovecii (PJP) prophylaxis with trimethoprim/sulfamethoxazole (TMP/SMX) provides coverage against Nocardia spp. unlike alternative agents such as atovaquone (ATQ), aerosolized pentamidine (AP), and dapsone. During the COVID-19 pandemic, patients receiving AP were transitioned to ATQ to avoid the use of nebulized medication. This, in turn, led to decreased use of TMP/SMX as patients on oral ATQ were not reassessed for the use of TMP/SMX as would have occurred while on AP. Additionally, an increased incidence of Nocardia infections was observed during this time. The objective of this study was to determine the association between the incidence of Nocardia infections and number of TMP/SMX prophylaxis-days in pre- versus COVID-19 cohorts.MethodsThis was a single center retrospective chart review of all renal transplant recipients between September 2018 – August 2019 (pre-COVID-19 cohort) and April 2020 – March 2021 (COVID-19 cohort). Patients were included if they were at least 18 years of age and a recipient of a cadaveric or living donor kidney transplant. Exclusion criteria included multi-organ transplant, pediatric patients, and repeat transplants. The primary outcome was incidence of Nocardiosis within the first 6 months post-transplant in the pre- and COVID-19 cohorts.ResultsA total of 218 patients were included (Table 1). Induction therapy and initial immunosuppression did not differ significantly between groups, nor did rates of rejection within 180 days of transplant (Table 2). Although the pre-COVID-19 cohort had a higher rate of neutropenia, there was no difference in median absolute lymphocyte count between the two groups. The COVID-19 cohort had a decreased percentage of TMP/SMX prophylaxis-days (59.2% vs. 72.5%, p < 0.0001) and an increased incidence of Nocardia infections in the first 6 months post-transplant (4% vs. 0%, p=0.0292). All 4 cases of Nocardia infections occurred in patients receiving ATQ. ConclusionThe increased incidence of Nocardiosis was associated with a decreased use of TMP/SMX for PJP prophylaxis which may have been an unintended consequence of increased use of ATQ in lieu of AP during COVID-19.Disclosures All Authors: No reported disclosures