Rok Kogoj

Dr. Rok Kogoj

University of Ljubljana, Faculty of Medicine, Institute of Microbiology and Immunology
orcid

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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17 September 2015 in Eurosurveillance
Verified
Journal Article
Open access
RKRok Kogoj
Rok Kogoj
TMTatjana Mrvic
Tatjana Mrvic
MPMarina Praprotnik
Marina Praprotnik
DKDarja Kese
Darja Kese
In this retrospective study we employed real-time polymerase chain reaction (PCR) to analyse the occurrence of Mycoplasma pneumoniae among upper and lower respiratory tract infections (RTI) in the Central Region of Slovenia between January 2006 and December 2014. We also used a culture and pyrosequencing approach to genotype strains and infer their potential macrolide resistance. Of a total 9,431 tested samples from in- and out-patient with RTI, 1,255 (13%) were found to be positive by M. pneumoniae PCR. The proportion of positive samples was 19% (947/5,092) among children (?16 years-old) and 7% (308/4,339) among adults (>16 years-old). Overall, among those PCR tested, the highest proportions of M. pneumoniae infections during the study period were observed in 2010 and 2014. In these two years, 18% (218/1,237) and 25% (721/2,844) of samples were positive respectively, indicating epidemic periods. From the 1,255 M. pneumoniae PCR-positive samples, 783 (614 from paediatric and 169 from adult patients) were successfully cultured. Of these, 40% (312/783) were constituted of strains belonging to the P1 type II genomic group, while 60% (469/783) contained strains of the P1 type I group. Two isolates comprised both P1 type I and II strains. Results of a genotype analysis by year, showed that the dominant M. pneumoniae P1 type during the 2010 epidemic was P1 type II (82% of isolates; 81/99), which was replaced by P1 type I in the 2014 epidemic (75%; 384/510). This observation could indicate that the two epidemics may have been driven by a type shift phenomenon, although both types remained present in the studied population during the assessed period of time. Only 1% of strains (7/783) were found to harbour an A2063G mutation in the 23S rRNA gene, which confers macrolide resistance, suggesting that the occurrence of M. pneumoniae macrolide resistance still seems to be sporadic in our geographic area.

4 February 2016 in Eurosurveillance
Verified
Journal Article
Open access
MMMojca Matičič
Mojca Matičič
IKIrena Klavs
Irena Klavs
JZJerneja Videčnik Zorman
Jerneja Videčnik Zorman
DVDarja Vidmar Vovko
Darja Vidmar Vovko
RKRok Kogoj
Rok Kogoj
DKDarja Keše
Darja Keše
A laboratory-confirmed lymphogranuloma venereum (LGV) case in Slovenia was reported in 2015, in a human immunodeficiency virus (HIV)-negative man presenting with inguinal lymphadenopathy. He reported unprotected insertive anal intercourse with two male partners in Croatia. Variant L2c of Chlamydia trachomatis was detected in clinical samples. Although the patient was eventually cured, the recommended treatment regimen with doxycycline had to be prolonged.

5 July 2013 in Scandinavian Journal of Infectious Diseases
Verified
Journal Article
Closed access
VSVesna Cvitkovic Spik
Vesna Cvitkovic Spik
BBBojana Beovic
Bojana Beovic
MPMarko Pokorn
Marko Pokorn
ATAna Drole Torkar
Ana Drole Torkar
DVDarja Vidmar
Darja Vidmar
MPManica Müller Premru
Manica Müller Premru
Background: The aim of the study was to assess the performance of a real-time polymerase chain reaction (rt-PCR) assay on plasma and respiratory samples for the diagnosis of pneumococcal pneumonia. Methods: Three hundred and forty patients (160 children and 180 adults) with community-acquired pneumonia were included prospectively from January 2011 to May 2012. Blood samples were obtained simultaneously for culture and rt-PCR targeting the lytA gene. Respiratory samples were also obtained: nasopharyngeal swab in nearly all patients and sputum or tracheal aspirate when available. Results: Streptococcus pneumoniae was detected in 222 (65%) of 340 patients: 143 (89%) children and 79 (44%) adults. Pneumonia was assigned as definite pneumococcal in 96 (28.2%) of 340 patients, according to S. pneumoniae detected in blood: in 54 (33.8%) children – by rt-PCR in 51 (31.9%) and by culture in 5 (3.1%); and in 42 (23.3%) adults – by rt-PCR in 41 (22.8%) and by culture in 12 (6.7%). Pneumonia was considered as probably pneumococcal in 19 (10.6%) adults according to S. pneumoniae detected in sputum/tracheal aspirate, by rt-PCR in 19 and by culture in 5. In 18 adults and 89 children with S. pneumoniae detected only in the nasopharynx, pneumonia was considered as possibly pneumococcal; however it should be noted that nasopharyngeal colonization with S. pneumoniae is also common in children with other aetiologies of pneumonia. Conclusions: rt-PCR on plasma and other samples performed significantly better than culture for the detection of pneumococcal pneumonia (p < 0.0005) in children and adults.

5 June 2024 in Respiratory Research
Verified
Journal Article
Open access
PDF file
MLManca Luštrek
Manca Luštrek
ZCZala Cesar
Zala Cesar
ASAlen Suljič
Alen Suljič
RKRok Kogoj
Rok Kogoj
NKNataša Knap
Nataša Knap
MKMisa Korva
Misa Korva
Background: The concurrent circulation of SARS-CoV-2 with other respiratory viruses is unstoppable and represents a new diagnostic reality for clinicians and clinical microbiology laboratories. Multiplexed molecular testing on automated platforms that focus on the simultaneous detection of multiple respiratory viruses in a single tube is a useful approach for current and future diagnosis of respiratory infections in the clinical setting. Methods: Two time periods were included in the study: from February to April 2022, an early 2022 period, during the gradual lifting of COVID-19 prevention measures in the country, and from October 2022 to April 2023, the 2022/23 respiratory infections season. We analysed a total of 1,918 samples in the first period and 18,131 respiratory samples in the second period using a multiplex molecular assay for the simultaneous detection of Influenza A (Flu-A), Influenza B (Flu-B), Human Respiratory Syncytial Virus (HRSV) and SARS-CoV-2. Results: The results from early 2022 showed a strong dominance of SARS-CoV-2 infections with 1,267/1,918 (66.1%) cases. Flu-A was detected in 30/1,918 (1.6%) samples, HRSV in 14/1,918 (0.7%) samples, and Flu-B in 2/1,918 (0.1%) samples. Flu-A/SARS-CoV-2 co-detections were observed in 11/1,267 (0.9%) samples, and HRSV/SARS-CoV-2 co-detection in 5/1,267 (0.4%) samples. During the 2022/23 winter respiratory season, SARS-CoV-2 was detected in 1,738/18,131 (9.6%), Flu-A in 628/18,131 (3.5%), Flu-B in 106/18,131 (0.6%), and HRSV in 505/18,131 (2.8%) samples. Interestingly, co-detections were present to a similar extent as in early 2022. Conclusion: The results show that the multiplex molecular approach is a valuable tool for the simultaneous laboratory diagnosis of SARS-CoV-2, Flu-A/B, and HRSV in hospitalized and outpatients. Infections with Flu-A/B, and HRSV occurred shortly after the COVID-19 control measures were lifted, so a strong reoccurrence of various respiratory infections and co-detections in the post COVID-19 period was to be expected.

8 June 2022 in Journal of Medical Virology
Verified
Journal Article
Open access
TTTina Tina
Tina Tina
RKRok Kogoj
Rok Kogoj
JŠJaka Šikonja
Jaka Šikonja
DRDamijana Roškarič
Damijana Roškarič
MVMonika Jevšnik Virant
Monika Jevšnik Virant
MPMiroslav Petrovec
Miroslav Petrovec
A prospective cohort study was conducted during the Delta and Omicron severe acute respiratory syndrome coronavirus type 2 (SARS‐CoV‐2) epidemic waves from paired nasopharyngeal swab (NPS or NP swab) and saliva samples taken from 624 participants. The study aimed to assess if any differences among participants from both waves could be observed and if any difference in molecular diagnostic performance could be observed among the two sample types. Samples were transported immediately to the laboratory to ensure the highest possible sample quality without any freezing and thawing steps before processing. Nucleic acids from saliva and NPS were prospectively extracted and SARS‐CoV‐2 was detected using a real‐time reverse‐transcription polymerase chain reaction. All observed results were statistically analyzed. Although the results obtained with NP and saliva agreed overall, higher viral loads were observed in NP swabs regardless of the day of specimen collection in both SARS‐CoV‐2 epidemic waves. No significant difference could be observed between the two epidemic waves characterized by Delta or Omicron SARS‐CoV‐2. To note, Delta infection resulted in higher viral loads both in NP and saliva and more symptoms, including rhinorrhea, cough, and dyspnea, whereas Omicron wave patients more frequently reported sore throat. An increase in the mean log RNA of SARS‐CoV‐2 was observed with the number of expressed symptoms in both waves, however, the difference was not significant. Data confirmed that results from saliva were concordant with those from NP swabs, although saliva proved to be a challenging sample with frequent inhibitions that required substantial retesting.

1 August 2021 in The Journal of Molecular Diagnostics
Verified
Journal Article
Open access
RKRok Kogoj
Rok Kogoj
PKPetra Kmetič
Petra Kmetič
AVAnja Oštrbenk Valenčak
Anja Oštrbenk Valenčak
KKKristina Fujs Komloš
Kristina Fujs Komloš
KSKatja Seme
Katja Seme
MPMario Poljak
Mario Poljak
Abbott’s Alinity m is a recently launched fully integrated, automated molecular analyzer allowing continuous loading of samples and sample-to-result molecular detection of several microorganisms. Manufacturer-independent clinical evaluation of Alinity m SARS-CoV-2 (Alinity) against cobas 6800 SARS-CoV-2 (cobas) as a standard comparator was performed on 2,157 consecutive nasopharyngeal swabs. Valid initial results of Alinity and cobas were obtained from 2,129/2,157 (98.7%) and 2,157/2,157 (100%) samples, respectively. Overall percent agreement of 98.3% (2,092/2,129; 95%CI:97.6–98.7%), positive percent agreement of 100.0% (961/961; 95%CI:99.6–100.0%), negative percent agreement of 96.8% (1,131/1,168; 95%CI:95.7–97.7%), and a high kappa value of 0.965 (95%CI:0.954–0.976) were observed on 2,129 samples with valid results for both assays. There were 37 discordant results and based on discordant analyses, including previous and/or follow-up PCR results, 22 could be considered Alinity analytically true positive with high probability. Due to the lack of additional information and inability of repeated/further testing, the status of the remaining 15 discordant samples remains unresolved. Comparative real-life throughput of both analyzers assessed while testing 564 samples in parallel across two 8-hour shifts and comparative turnaround time assessment measured while processing in parallel the first 94 routine samples received in the laboratory each working day for 5 consecutive days showed similar real-life performance of both analyzers with certain differences, which has potential importance in some laboratory settings.