1.Conventional versus molecular detection of Chlamydia trachomatis and Neisseria gonorrhoeae among males in a sexually transmitted infections clinic
Siti Fazilah Situ ; Chuan Hun Ding ; Ramliza Ramli
The Malaysian Journal of Pathology 2017;39(1):25-31
Chlamydia trachomatis and Neisseria gonorrhoeae are important bacterial pathogens
of sexually transmitted infections (STIs) worldwide. This study sought to compare the analytical
sensitivity and specificity of conventional methods against a rapid molecular method in detecting
STIs caused by these bacteria. Methods: Ninety five first-time male attendees of the Genito-urinary
Medicine Clinic in Hospital Kuala Lumpur were included in this cross-sectional study. The detection
of C. trachomatis was achieved through direct fluorescence antibody (DFA) staining of urethral
swabs and real-time polymerase chain reaction testing (Xpert® CT/NG assay) on urine specimens.
N. gonorrhoeae was detected through Gram staining and culture of urethral swabs and Xpert® CT/
NG assay on urine specimens. Results: From the Xpert® CT/NG results, 11 (11.6%) attendees had
chlamydia, 23 (24.2%) had gonorrhoea and 8 (8.4%) had both STIs. The sensitivity and specificity
of DFA in detecting chlamydia compared to Xpert® CT/NG were 5.3% (95% CI: 0-28) and 94.7%
(95% CI: 86-98), respectively. For gonorrhoea, the sensitivity and specificity of Gram staining were
90.3% (95% CI: 73-98) and 95.3% (86-99), respectively, whereas the sensitivity and specificity of
culture compared to Xpert® CT/NG were 32.2% (95% CI: 17-51) and 100% (95% CI: 93-100),
respectively. Conclusion: Although Gram-stained urethral swab smears are sensitive enough to be
retained as a screening tool for gonorrhoea, culture as well as DFA lack sensitivity and are poorly
suited to screen for gonorrhoea and chlamydia, respectively. However, owing to their high specificity,
conventional detection methods are still suitable as confirmatory tests for gonorrhoea and chlamydia.
2.The reliability of a rapid molecular detection method in determining the prevalence of rifampicin-resistant Mycobacterium tuberculosis in an urban district health facility in Malaysia
The Malaysian Journal of Pathology 2020;42(3):401-407
Introduction: Rifampicin is a key first-line antimycobacterial agent employed for the treatment of
pulmonary tuberculosis (PTB). This study sought to obtain prevalence data on rifampicin-resistant
Mycobacterium tuberculosis among smear-positive PTB patients in the Klang District of Malaysia.
Materials and Methods: A total of 103 patients from the Chest Clinic of Hospital Tengku Ampuan
Rahimah with sputum smears positive for acid-fast bacilli were included in this cross-sectional
study. All sputa were tested using Xpert MTB/RIF to confirm the presence of M. tuberculosis
complex and detect rifampicin resistance. Sputa were also sent to a respiratory medicine institute
for mycobacterial culture. Positive cultures were then submitted to a reference laboratory, where
isolates identified as M. tuberculosis complex underwent drug susceptibility testing (DST). Results:
A total of 58 (56.3%) patients were newly diagnosed and 45 (43.7%) patients were previously
treated. Xpert MTB/RIF was able to detect rifampicin resistance with a sensitivity and specificity
of 87.5% and 98.9%, respectively. Assuming that a single resistant result from Xpert MTB/RIF
or any DST method was sufficient to denote resistance, a total of 8/103 patients had rifampicinresistant M. tuberculosis. All eight patients were previously treated for PTB (p<0.05). The overall
prevalence of rifampicin resistance among smear-positive PTB patients was 7.8%, although it was
17.8% among the previously treated ones. Conclusion: The local prevalence of rifampicin-resistant
M. tuberculosis was particularly high among previously treated patients. Xpert MTB/RIF can be
employed in urban district health facilities not only to diagnose PTB in smear-positive patients, but
also to detect rifampicin resistance with good sensitivity and specificity.
3.Trichosporon asahii fungaemia in an immunocompetent polytrauma patient who received multiple antibiotics
The Malaysian Journal of Pathology 2020;42(2):293-296
Trichosporon asahii is a yeast-like fungus that is emerging as an important cause of invasive infections
in tertiary medical centres. A 58-year-old Chinese man with no known medical illnesses presented
with liver lacerations and multiple fractures following an alleged 12-foot fall at a construction
site. The gravity of his injuries and poor haemodynamic status necessitated an intensive care unit
(ICU) admission, during which several febrile episodes were detected and multiple antibiotics were
administered. After being in the ICU for at least two weeks, a urease-positive yeast was isolated from
the patient’s blood. The yeast formed dry, fuzzy and wrinkled white colonies on Sabouraud dextrose
agar following prolonged incubation, and produced blastoconidia, true hyphae, pseudohyphae and
arthroconidia on slide culture. It was identified biochemically by the ID 32 C kit as T. asahii. The
yeast had elevated minimal inhibitory concentration (MIC) values to fluconazole, amphotericin B,
flucytosine and all echinocandins tested. In view of this, the patient was treated with voriconazole
and was successfully transferred to the general medical ward.
4.The crucial role of molecular testing to facilitate the diagnosis of pneumocystis pneumonia during pregnancy
Chuan Hun DING ; Hamidah YUSOFF ; Najihan Abdul Samat Muttaqillah ; Yee Loong TANG ; Toh Leong TAN ; Petrick PERIYASAM ; Andrea Yu-Lin BAN
The Malaysian Journal of Pathology 2018;40(1):67-72
Pneumocystis pneumonia is an important human immunodeficiency virus (HIV)-associated opportunistic infection, and especially so in pregnant HIV-positive patients. We report a case of a 40-year-old woman in her first trimester of pregnancy who initially presented with acute gastroenteritis symptoms but due to a history of high-risk behaviour and the observation of oral thrush, she was worked up for HIV infection. Her retroviral status was positive and her CD4+ T cell count was only 8 cells/mL. She was also worked up for pneumocystis pneumonia due to the presence of mild resting tachypnoea and a notable drop in oxygen saturation (from 100% to 88%) following brief ambulation. Her chest radiograph revealed bilaterally symmetrical lower zone reticular opacities and Giemsa staining of her bronchoalveolar lavage (BAL) was negative for Pneumocystis jirovecii cysts. However, real-time P. jirovecii polymerase chain reaction (PCR) testing on the same BAL specimen revealed the presence of the organism. A course of oral co-trimoxazole plus prednisolone was commenced and her clinical condition improved.