Running head: nontuberculous mycobacteria in CroatiaWord count: 2354 Correspondence Mateja Jankovic, University Hospital Centre Zagreb, Department for Respiratory Diseases, Jordanovac 104, 10 000 Zagreb, Croatia; Email: mateja.jankovic@gmail.com Key words: atypical mycobacteria, epidemiological study, geographical diversity, pulmonary nontuberculous mycobacterial disease, Jankovic, M., Samarzija, M., Sabol, I., Jakopovic, M., Katalinic Jankovic, V., Zmak, L., Ticac, B., Marusic, A., Obrovac, M., van Ingen, J., 2013. Geographical Jankovic, M., Samarzija, M., Sabol, I., Jakopovic, M., Katalinic Jankovic, V., Zmak, L., Ticac, B., Marusic, A., Obrovac, M., van Ingen, J., 2013. Geographical distribution and clinical relevance of non-tuberculous mycobacteria in Croatia. The International Journal of Tuberculosis and Lung Disease 17,[836][837][838][839][840][841]

Stricter criteria should be used for species of low clinical relevance, and less stringent criteria for species of high relevance in the local setting.3

How to cite this article: Gjurčević E, Kužir S, Žmak L, et al. A case of mycobacteriosis in farmed pikeperch (Sander lucioperca) cultured in a recirculating aquaculture system. Aquac Res.

Nontuberculous mycobacteria (NTM) are opportunistic pathogens found in natural and human-engineered waters. In 2009, a relative increase in the isolation of Mycobacterium gordonae from pulmonary samples originating from General Hospital Zabok was noted by the National Mycobacteria Reference Laboratory. An epidemiological survey revealed a contamination of the cold tap water with M. gordonae and guidelines regarding sputum sample taking were issued. In addition, all incident cases of respiratory infection due to NTM reported from 2007 to 2012 at General Hospital Zabok were included in a retrospective review. Out of 150 individual NTM isolates, M. gordonae was the most frequently isolated species (n = 135; 90%) and none of the cases met the criteria of the American Thoracic Society for pulmonary NTM disease. While concomitant Mycobacterium tuberculosis infection was confirmed in only 6 (4%) patients, anti-tuberculosis treatment was initiated for a significant portion of patients (n = 64; 42.6%) and unnecessary contact tracing was performed. This study points out the need to enhance the knowledge about NTM in our country and indicates the importance of faster NTM identification, as well as the importance of good communication between laboratory personnel and physicians when evaluating the significance of the isolated NTM.

Background: Due to rapid spread, the Omicron variant has become the dominant SARS-CoV-2 variant responsible for infections worldwide. We present the first detection of the Omicron variant in Croatia which resulted in rapid cross-border spreading. Methods: Whole-genome sequencing was performed using the Illumina MiniSeq sequencing system. SARS-CoV-2 lineages were identified using the PANGOLIN and GISAID databases. Results: The first case of the Omicron variant (BA.1.17) emerged in Croatia after a workshop held in Zagreb in November 2021. The patient reported a history of previous COVID-19 and received two doses of an mRNA vaccine. Three additional cases were detected among Croatian participants of the workshop. At the beginning of December, SARS-CoV-2 infection was confirmed in one participant from Montenegro and her husband. Phylogenetic analysis showed that the detected Omicron variants were closely related to the first Croatian case, confirming the connection with the workshop outbreak and rapid cross-border spreading. Subsequent analyses of SARS-CoV-2 positive samples in Croatia showed the rapid introduction of the Omicron variant and depletion of the Delta variant resulting in the fifth pandemic wave. Conclusions: Genomic monitoring and early detection of novel SARS-CoV-2 variants are essential to implement timely epidemiological interventions and reduce further transmission in the population.

The most prevalent global lineage in Croatia is Euro-American (sub-lineages Haarlem, S, Cameroon, and Latin American-Mediterranean). The high clustering rate and high medium clustering size of 4.2 tuberculosis cases could indicate a possible failure in interrupting the transmission of infection and points to the need for improvements in national and local tuberculosis control activities. This is the first study describing the molecular epidemiology of tuberculosis in Croatia.

An outbreak of tuberculosis among bovines and pigs caused by Mycobacterium caprae is described in this paper. After tuberculin skin tests with bovine purified protein derivates (PPD) six cattle and one sow, own by a small family farm, tested positive whilst three pigs were suspected in 2004. All animals were euthanised and checked for gross pathological lesions. Generalised lesions were found in five cattle and two sows; however one calf and two gilts had lesions that were localised in the submandibular lymph nodes. Mycobacteria were isolated from tissue samples of six cattle and four pigs. Mycobacterial isolates were identified using classical biochemical tests and molecular methods (PCR, GenoType MTBC) as M. caprae. Mycobacterial Interspersed Repetitive Unit (MIRU) typing of isolated mycobacteria showed an identical number of repeats in 12 different loci. Results of the research confirmed the domination of M. caprae among infected cattle in Croatia; however this paper was the first to confirm a case of M. caprae in pigs. The source of the infection was not found.

The zoonotic potential of Mycobacterium tuberculosis complex species is well known. However, M. pinnipedii, the causative agent of tuberculosis (TB) predominantly in seals and sea lions, has never been isolated from a respiratory specimen in humans. Here we describe the first known human case of pulmonary TB caused by M. pinnipedii in a 79-year-old female patient with rheumatoid arthritis and chronic respiratory disease. The epidemiological data did not explain where the patient was exposed to M. pinnipedii, thus leaving the source of transmission unknown.