Rapid diagnosis of tuberculosis using Xpert MTB/RIF assay - report from a developing country

To evaluate the diagnostic accuracy of the Xpert MTB/RIF assay for the detection of M. tuberculosis in pulmonary and extrapulmonary specimens and to compare it with conventional techniques. During a period of 10 months from December 2012 through September 2013, two hundred and forty five clinically TB suspects were enrolled for Xpert MTB RIF assay. The cohort comprised of 205 suspects of pulmonary TB and 40 of extrapulmonary TB [EPTB]. The 40 EPTB samples included pus aspirated from different sites of the body [n=19], pleural fluid [n=11], ascitic fluid [n=7], pericardial fluid, CSF and urine one each. Ziehl-Neelsen [ZN] Stained smear microscopy, culture on LJ media and Xpert MTB/RIF assay was performed on samples from these patients. M. tuberculosis [MTB] were detected by Xpert MTB/RIF test in 111 [45.3%] out of 245 samples. Of these, 85 [34.7%] were smear positive on ZN staining and 102 [41.6%] were positive on LJ cultures. Rifampicin resistance was detected in 16 [6.5%] patients. Nine out of 19 pus samples [47.3%] were positive for MTB by Gene Xpert, 03 [15.8%] on ZN staining and 04 [21%] on LJ culture. MTB could not be detected in any other extrapulmonary sample. Xpert MTB/RIF is a sensitive method for rapid diagnosis of Tuberculosis, especially in smear negative cases and in EPTB as compared to the conventional ZN staining. Among EPTB cases the highest yield of positivity was shown in Pus samples. For countries endemic for TB GeneXpert can serve as a sensitive and time saving diagnostic modality for pulmonary and EPTB

Nosocomial methicillin-resistant staphylococcus aureus frequency in a tertiary care hospital, Lahore, Pakistan

Methicillin-resistant Staphylococcus aureus [MRSA] is one of the most important nosocomial pathogens world wide. The present descriptive study was carried out to determine the frequency of MRSA isolates in Jinnah Hospital Lahore, which is a major tertiary care hospital. Staphylococcus aureus [S. aureus] isolates recovered from various clinical samples received from inpatient departments of Jinnah Hospital Lahore [JHL] were included in the study. Screening for MRSA was done by modified Kirby-Bauer disc diffusion technique according to the CLSI guide lines. A total of 864 isolates of S. aureus were cultured. Two hundred and forty [27.77%] were found to be MRSA. Maximum isolation was from endotracheal tubes and ceritral venous [CV] catheters. MRSA infections are emerging as a serious health problem in our set up. Joint efforts by clinicians, clinical microbiologists, hospital management and public health authorities are required to meet the challenge of MRSA on the forefront

Frequency of extended spectrum beta lactamase producing gram negative bacilli among clinical isolates

Extended-spectrum beta-lactamase [ESBL]-producing bacteria are emerging pathogens. They are descended by genetic mutation from native beta-lactamases found in gram negative bacteria, especially infectious strains of Escherichia coli and Klebsiella species. Clinicians, microbiologists, infection control practitioners, and hospital epidemiologists are concerned about ESBL-producing bacteria because of the increasing incidence of such infections, the limitations of effective antimicrobial drug therapy, and adverse patient outcomes. The present study was undertaken to determine the frequency of ESBL producing gram negative bacilli recovered from clinical specimens in our setup. A total of 3099 gram negative isolates recovered from various clinical samples during the period of January 2007 to December 2008 were processed for the detection of ESBL production. Among them 35.5% bacterial strains were found to be ESBL producers. The commonest ESBL producing organism isolated was Escherecia coli [44.8%], followed by Klebsiella pneumoniae [38.6%]. Production of ESBLs by gram negative bacteria is emerging as a widespread problem in our setup. Appropriate infection control and antibiotic management strategies are needed to stem the spread of this emerging form of resistance

Vulvovaginal candidiasis in pregnancy

Vulvovaginal candidiais [VVC] is a common cause of vaginitis during pregnancy. Although the disease is rarely life threatening, it is a source of great physical and psychological discomfort and suffering. High Vaginal swabs [HVS] were collected from 50 pregnant women and subjected to Gram's smear, 10% KOH wet mount and culture. Candida was isolated from 48% of all cultures. However, Gram's smear and KOH mount revealed only 38% positivity with 10% showing both Candida spores and pseudohyphae. Multigravidae [60%] were more commonly affected than primigravidae [40%]. The common presenting signs and symptoms of VVC in present study were excessive vaginal discharge [100%], vaginal pruritis [91.6%] and vaginal burning [75%]. Although Gram's stain/ KOH mount is a valuable method in rapid diagnosis of symptomatic VVC as the invasive forms of yeast can also be demonstrated, yet its low sensitivity as compared to cultures could restrict the use in routine practice. Thus the best approach for the diagnosis of VVC is a combination of culture and Gram's smear/ or KOH mount

Bacterial meningitis: a diagnostic approach

Over a thirteen months period, 456 patients clinically suspected of having bacterial meningitis were investigated. Cerebrospinal fluid [CSF] specimens were examined by Gram's stain, white cell [WBC] counts and culture techniques. Gram's stain and cultures of CSF [232] with a cell count of less than 10 cells/mm[3] were consistently negative. However, of the CSF specimens [88] with cell counts greater than l00/mm[3], 28 [6.7%] and 23 [5.2%] of the specimens were positive by cultures and Gram's stain respectively. A total of 31 isolates were identified by culture. Streptococcus pneumoniae [22.4%], Escherichia coli [16%], and Coagulase negative Staphylococci [16%] were the predominant organisms, followed by Haemophilus influenzae [6.4%] and Neisseria men ingitidis [2.6%]. Thus it was concluded that Gram's stain and perhaps culture of CSF with cell counts of less than l0/mm[3] are of no practical diagnostic significance and may be eliminated as routine procedures. The gold standard for the diagnosis of bacterial meningitis is raised WBC cell count [>100/mm[3]], positive Gram's smear and/ or culture of CSF specimen

Chromoblastomycosis: an unusual cutaneous dematiaceous fungal infection

Chromoblastomycosis is a chronic fungal infection with a slow evolution, caused by dematiaceous fungi inducing skin lesions being difficult to treat and have frequent recurrences. The clinicopathological features and diagnosis of one such case is reported here to share our experience with others. A nine years old male with a three years history of a slowly spreading painless skin lesion involving the whole of right cheek and nose. The patient gave a typical history of trauma in that region followed by a dark red skin eruption, which gradually grew to form erythematous papule. Physical examination revealed large hyperkeratotic, raised, thick crusted, verrucous plaques with areas of scaring and ulceration on the right cheek and nose extending down in a tumorous fashion. A small scaly lesion was observed next to the right eyebrow. However, the borders of the lesion were well defined and the surrounding skin was normal. No lymphadenopathy was seen