u.a. zainulabid, s. wei, n. kamarudin, p. periyasamy, h.f. ahmad.  (2023).  tapping the pathogenic bacteria from hospital water tap system in malaysia using flongle nanopore.  - international journal of infectious diseases.  S6. 

hui jan tan, abdool alleem hj shahren, ching soong khoo, chen fei ng, wan asyraf wan zaidi, najma kori, petrick periyasamy, choon leng eu, alvin oliver payus, rozita hod.  (2023).  anxiety among hospitalized covid-19 patients: a case-control study from a tertiary teaching hospital in malaysia.  - frontiers in psychiatry.  1-13. 

nazrul anuar nayan, choon jie yi, mohd zubir suboh, nur-fadhilah mazlan, petrick periyasamy, muhammad yusuf zawir abdul rahim and shamsul azhar shah.  (2022).  covid-19 prediction with machine learning technique from extracted features of photoplethysmogram morphology.  - frontiers in public health.  1-11. 

chee ll, petrick p, muhd nordin s, sarah anne r, lay yg, suet yc, kiew bp, shue hk, farah waheeda t, mei ky, sheah lg, nur jannah a, xin yc, poy kl, stephanie wyt, dexter vd, ramliza r, toh lt, aliza my, saw kc, wan rahiza wm, isa naina-mohamed.  (2022).  plethora of antibiotics usage and evaluation of carbapenem prescribing pattern in intensive care units: a single-center experience of malaysian academic hospital.  - antibiotics.  1-19. 

syarifah syahirah syed abas,noralisa abdul karim,petrick periyasamy,nurasyikin yusof,shamsul azhar shah,tan toh leong,saiful safuan md sani,hanita othman,sharifah azura salleh,nurul nadiah mohd zaidi,s fadilah abdul wahid,wan fariza wan jamaludin.  (2022).  correlation of dengue warning signs during febrile phase with rotational thromboelastometry, cortisol and feritin.  - international journal of environmental research and public health.  1-15. 

tuang wei xuan, palaniapan sivakumar, periyasamy petrick.  (2022).  first reported case of cladosporium liver abscess in immunocompromised host.  - medical mycology.  194. 

emelia osman, nur azma amin, thieeraporn phraseart ma noon, siti nuratiqah hanani lahat, mohamad syairazi rosli, shazia farhana sham, petrick ramesh periyasamy, nuraffini ghazali,siti nor azreen abd manap, and rahmah noordin.  (2022).  comparison of two serological assays in detecting strongyloides infection in immunocompromised patients.  - american journal of tropical medicine and hygiene.  636-639. 

nurul adilla hayat jamaluddin, petrick periyasamy, chee lan lau, sasheela ponnampalavanar, pauline siew mei lai, ramliza ramli, toh leong tan, najma kori, mei kuen yin, nur jannah azman, rodney james, karin thursky and isa naina mohamed.  (2021).  point prevalence survey of antimicrobial use in a malaysian tertiary care university hospital.  - antibiotics.  1-13. 

petrick periyasamy, ng boon hau, umi kalsom satariah ali, zetti zainol rashid, najma kori.  (2021).  aerosolized sars-cov-2 transmission risk: surgical or n95 masks?.  - infection control & hospital epidemiology.  1150-1152. 

azlina ibrahim, isa naina mohamed, lau chee lan, ramliza ramli, najma kori, petrick periyasamy.  (2021).  an observational prospective study on the appropriateness of ceftriaxone use in medical wards of ppukm.  - international journal of infectious diseases (ijid).  104. 

wan asyraf wan zaidi, muhamad danial zulkifli, najma kori, petrick k. periyasamy, wan nur nafisah wan yahya.  (2021).  ischaemic stroke in covid-19 patients in hospital canselor tuanku muhriz, national university of malaysia medical centre.  - international journal of stroke.  159. 

petrick periyasamy, navaneedha lingam mahalingam, najma kori, andrea ban yu lin, ramliza ramli, isa naina mohamed, lau chee lan.  (2021).  time to clinical stability in hcap in a tertiary center hospital in kuala lumpur.  - international journal of infectious diseases.  106. 

nurnabila syafiqah muhamad rizal, hui-min neoh, ramliza ramli, petrick @ ramesh a/l k periyasamy, alfizah hanafiah ,muttaqillah najihan abdul samat, toh leong tan, kon ken wong, sheila nathan, sylvia chieng, seow hoon saw, bee yin khor.  (2021).  16s rrna gene next-generation sequencing (16sngs) for bacterial pathogen identification: pilot study in a malaysian teaching hospital.  - international journal of infectious diseases.  180-203. 

ahmad izuddin mustaffa, petrick periyasamy, lau chee lan, ramliza ramli, najma kori,.  (2021).  the overly attached bacteria.  - international journal of infectious disease.  167-168. 

d. muhamad, p. periyasamy, r. ramli, l. chee lan, r. abdul rahman.  (2021).  impact of infectious diseases specialists in intensive care unit on antimicrobial utilization and patient outcomes.  - international journal of infectious diseases.  113. 

chien-chang leea, andrea lay hoon kwaa, anucha apisarnthanarak, jia-yih feng,eric howard gluck, akihiro ito, anis karuniawati, petrick periyasamy, busadee pratumvinit,jeetendra sharma, rontgene solante, subramanian swaminathan, niraj tyagi, dien minh v....  (2020).  procalcitonin (pct)-guided antibiotic stewardship in asia-pacific countries: adaptation based on an expert consensus meeting.  - clinical chemistry and laboratory medicine (cclm).  1983-1991. 

nurnabila syafiqah muhamad rizal, hui-min neoh, ramliza ramli, petrick @ ramesh a/l k periyasamy, alfizah hanafiah, muttaqillah najihan abdul samat, toh leong tan, kon ken wong, sheila nathan, sylvia chieng, seow hoon saw, bee yin khor.  (2020).  advantages and limitations of 16s rrna next-generation sequencing for pathogen identification in the diagnostic microbiology laboratory: perspectives from a middle-income country.  - diagnostics.  1-19. 

azlina ibrahim, isa naina mohamed, chee lan lau, ramliza ramli, najma kori, petrick periyasamy.  (2019).  appropriateness of ceftriaxone use in medical wards of ukmmc - how compliant are we?.  - antimicrobial resistance and infection control.  148. 

najma kori, razman jarmin, petrick periyasamy, lau chee lan.  (2019).  new perspective of antimicrobial stewardship: changing surgeon's paradigm.  - antimicrobial resistance and infection control.  144-145. 

nasheeda saeed, ching soong khoo, rabani remli, zhe kang law, petrick periyasamy, syazarina sharis osman and hui jan tan.  (2018).  first reported case of neuroleptospirosis complicated with anton's syndrome.  - frontiers in neurology.  1-5. 

choon seong ng, shahrul azmin, zhe kang law, ramesh sahathevan, wan nur nafisah wan yahya, rabani remli, petrick periyasamy, norlinah mohd ibrahim and hui jan tan.  (2015).  an unusual neurological complication from a garden-variety organism: post-melioidosis parkinsonism.  - the medical journal of australia.  333-334. 

wan fariza wan jamaludin,petrick periyasamy, wan rahiza wan mat , s. fadilah abdul wahid.  (2015).  dengue infection associated hemophagocytic syndrome: therapeutic interventions and outcome.  - journal of clinical virology.  91-95. 

mohamed faisal abdul hamid, petrick periyasamy, andrea ban yu-lin, roslina abdul manap.  (2015).  a prospective cohort study comparing between pneumococcal and non-pneumococcal community-acquired pneumonia (cap) and health-care associated pneumonia (hcap) in ukmmc.  - respirology.  127. 

law zk, henry lj, alias nf, kumar s, sahathevan r, htwe o, naicker as.  (2015).  do stroke patients load on both lower limbs differently from what they perceive?.  - cerebrovascular diseases.  58. 

mohamed faisal, petrick periyasamy, andrea ban yu-lin, roslina abdul manap.  (2013).  detection rate of pneumococcal pneumonia using binaxnow streptococcus pneumoniae test, a prospective cohort study in a tertiary hospital in malaysia.  - respirology.  18(suppl 4) : 106. 

abdul aziz marwan, chai soon ngiu, petrick periyasamy.  (2013).  an interesting finding in a patient with chronic diarrhoea.  - annals academy of medicine singapore.  42(2):97-98. 

azlina abu bakar, cs ngiu, ms mohamad said, petrick periyasamy.  (2011).  salmonella related mycotic aneurysm with psoas and paraortic abscess treated.  - annals academy of medicine singapore.  40(10):467-468. 

deborah je marriott, petrick periyasamy.  (2011).  anticonvulsant hypersensitivity syndrome secondary to lamotrigine mimicking a septic episode.  - annals of the academy of medicine, singapore.  40(9):422-423. 

arif m shahar, chai soon ngiu, hasnur zaman hashim, hui jang tan, petrick periyasamy.  (2011).  no coma, but expressive dysphasia with cerebellar signs: an unique presentation of cerebral malaria.  - annals of academy of medicine singapore.  40(8):383-383.