Short-Finned Pilot Whale Strandings Associated with Pilot Whale Morbillivirus, Brazil

Cetacean morbillivirus (CeMV) causes illness and death in cetaceans worldwide; the CeMV strains circulating in the Southern Hemisphere are poorly known. We detected a pilot whale CeMV strain in 3 short-finned pilot whales (Globicephala macrorhynchus) stranded in Brazil during July–October 2020. Our results confirm this virus circulates in this species.

We performed RNA extractions of all available tissues with TRIzol-LS (Life Technologies Corporation, https://www.thermofisher.com). We performed a morbillivirus 2-step reverse transcription nested PCR to amplify the phosphoprotein gene (6). After DNA extraction with the QIAGEN Blood & Tissue Kit (QIAGEN, https://www.qiagen.com), we performed herpesvirus detection in lung (n = 2) and liver (n = 4) samples by nested pan-PCRs to amplify DNA polymerase and glycoprotein B genes (7); when those were positive, we tested the remaining Cetacean morbillivirus (CeMV) causes illness and death in cetaceans worldwide; the CeMV strains circulating in the Southern Hemisphere are poorly known. We detected a pilot whale CeMV strain in 3 short-finned pilot whales (Globicephala macrorhynchus) stranded in Brazil during July-October 2020. Our results confirm this virus circulates in this species.
available tissues using the same protocols. We calculated percentage of identity among the obtained sequences and the closest ones from GenBank/ EMBL/DDBJ based on p-distance. We used MEGA7 (https://www.megasoftware.net) to construct the phylogram (Figure).

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herpesvirus-negative by PCR. The obtained herpesvirus has the highest similarity (99.5% nt identity, 100% aa identity) to an alphaherpesvirus obtained in a striped dolphin (Stenella coeruleoalba) from Spain (GenBank accession no. GQ888671).
The general health of the CeMV-positive animals was poor, and all were undernourished. We compared the main pathologic findings in these animals to all other cases of PWMV strain reported in the literature (Table).
Pilot whales are susceptible to DMV and PWMV; DMV cause atypical pilot whale deaths in the Mediterranean Sea (6). By contrast, 4 cases of PWMV infections have been recorded; 1 in New Jersey, USA, and 3 in the Canary Islands, Spain (4-6,9,10). All of them had multiorgan infections (4,5). Case 1 likely had a subacute or systemic CeMV infection characterized by meningomyelitis with gliosis and lymphocytic bronchointerstitial pneumonia. Further studies are necessary to elucidate if cases 3 and 4 manifested an infection similar to the brain-only DMV form or a systemic infection with heterogenic dissemination. The poor nutritional condition observed in all PWMVpositive animals could be the result of decreased foraging capacity caused by encephalitis (1). Case 3 had alphaherpesvirus and CeMV co-infection, a comorbidity previously reported in cetaceans, including pilot whales (5,10); in this case, however, there were no associated herpesviral lesions. All PWMV-positive cetaceans we described were juveniles, which could be associated with maternal passive immunity loss.
The occurrence of pilot whale strandings in 2020 on the coast of Brazil could be considered atypical. Of interest, although case 1 was stranded >3,300 km away from case 3 along the coastline, it had the same PWMV sequence type, which suggests circulation of that type along the coast of Brazil. Further studies are necessary to understand the effects and epidemiology of morbillivirus in cetaceans in the South Atlantic Ocean. However, the high similarity between our sequences and the PWMV detected in the Northern Hemisphere confirms that this strain also circulates in South America pilot whales and might be enzootic in Globicephala sp. whales in the Atlantic Ocean.
M ycolicibacterium iranicum is a rapidly growing mycobacterium (RGM) and emerging cause of respiratory, wound, blood, and central nervous system infections (1,2). Phylogenetic analyses have shown that M. iranicum is more closely related to environmental mycobacterial species than pathogenic species (3), and most outbreaks have been associated with exposure to contaminated water (4,5).
Reports of nontuberculous mycobacteria infections have been increasing worldwide (6,7), predominantly in immunocompromised patients with hematologic or oncologic medical conditions (6). The rise in RGM detection is likely because of increased prevalence of immunocompromising conditions and improved access to molecular diagnostics (7). Molecular techniques, especially sequencing multiple conserved genes, such as rrs (16S rRNA), rpoB, and groEL (hsp65) (4), have led to a dramatic increase in mycobacterial species identified during the past 30 years. We describe a case of M. iranicum bacteremia associated with a long-term percutaneous catheter in an immunocompromised patient.
A woman, 76 years of age, with a history of polymyositis and hypertrophic obstructive cardiomyopathy was admitted to an academic hospital in Los Angeles, California, USA, because of substernal chest pain and dyspnea that began 1 day before. Her medications included prednisone (15 mg/d) and intravenous immunoglobulin (20 g administered every 10 days through a port-a-cath that had been in place for several years). The patient had taken mycophenolate mofetil until a month before hospital admission. During each intravenous immunoglobulin infusion over the past 2 years, she had experienced fevers, which were attributed to an infusion reaction. The most recent infusion was 4 days before admission.
The patient reported fatigue and generalized weakness for several days and an unintentional 25-pound weight loss over the past year. On hospital day 2, she was febrile with a temperature of 101°F (Appendix Figure, https://wwwnc.cdc.gov/EID/ article/29/1/22-0851-App1.pdf). Results of a preliminary work-up were unrevealing; however, after 4 days of incubation, multiple aerobic blood cultures (in BACTEC FX aerobic and F lytic media; Becton Dickinson, https://www.bd.com) taken from her port grew beaded, gram-positive rods with yellow mycobacteria-like colonies (Appendix Figure). Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry failed to identify the isolate. We performed a laboratory-developed, next-generation sequencing-based test that identified the organism as Mycolicibacterium iranicum, which we further verified using k-mer-based phylogenic analysis (Figure) (8). Using a previously described method for detection of macrolide resistance in Mycobacteroides abscessus (9), we did not detect a functional erm gene.
When blood cultures demonstrated Mycobacterium sp., we changed therapy and administered We describe a case of catheter-related bacteremia caused by Mycolicibacterium iranicum in the United States. The case highlights the value of using next-generation sequencing to identify infrequent and emerging pathogens and the challenges associated with choosing appropriate treatments because of limited knowledge of drug resistance mechanisms in those emerging pathogens.