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author:("lalith, M. K.")
1.  Spread of Carbapenem-Resistant Acinetobacter baumannii Global Clone 2 in Asia and AbaR-Type Resistance Islands 
Antimicrobial Agents and Chemotherapy  2013;57(11):5239-5246.
In this surveillance study, we identified the genotypes, carbapenem resistance determinants, and structural variations of AbaR-type resistance islands among carbapenem-resistant Acinetobacter baumannii (CRAB) isolates from nine Asian locales. Clonal complex 92 (CC92), corresponding to global clone 2 (GC2), was the most prevalent in most Asian locales (83/108 isolates; 76.9%). CC108, or GC1, was a predominant clone in India. OXA-23 oxacillinase was detected in CRAB isolates from most Asian locales except Taiwan. blaOXA-24 was found in CRAB isolates from Taiwan. AbaR4-type resistance islands, which were divided into six subtypes, were identified in most CRAB isolates investigated. Five isolates from India, Malaysia, Singapore, and Hong Kong contained AbaR3-type resistance islands. Of these, three isolates harbored both AbaR3- and AbaR4-type resistance islands simultaneously. In this study, GC2 was revealed as a prevalent clone in most Asian locales, with the AbaR4-type resistance island predominant, with diverse variants. The significance of this study lies in identifying the spread of global clones of carbapenem-resistant A. baumannii in Asia.
PMCID: PMC3811275  PMID: 23939892
3.  Changing Trends in Antimicrobial Resistance and Serotypes of Streptococcus pneumoniae Isolates in Asian Countries: an Asian Network for Surveillance of Resistant Pathogens (ANSORP) Study 
Antimicrobial resistance in Streptococcus pneumoniae remains a serious concern worldwide, particularly in Asian countries, despite the introduction of heptavalent pneumococcal conjugate vaccine (PCV7). The Asian Network for Surveillance of Resistant Pathogens (ANSORP) performed a prospective surveillance study of 2,184 S. pneumoniae isolates collected from patients with pneumococcal infections from 60 hospitals in 11 Asian countries from 2008 to 2009. Among nonmeningeal isolates, the prevalence rate of penicillin-nonsusceptible pneumococci (MIC, ≥4 μg/ml) was 4.6% and penicillin resistance (MIC, ≥8 μg/ml) was extremely rare (0.7%). Resistance to erythromycin was very prevalent in the region (72.7%); the highest rates were in China (96.4%), Taiwan (84.9%), and Vietnam (80.7%). Multidrug resistance (MDR) was observed in 59.3% of isolates from Asian countries. Major serotypes were 19F (23.5%), 23F (10.0%), 19A (8.2%), 14 (7.3%), and 6B (7.3%). Overall, 52.5% of isolates showed PCV7 serotypes, ranging from 16.1% in Philippines to 75.1% in Vietnam. Serotypes 19A (8.2%), 3 (6.2%), and 6A (4.2%) were the most prominent non-PCV7 serotypes in the Asian region. Among isolates with serotype 19A, 86.0% and 79.8% showed erythromycin resistance and MDR, respectively. The most remarkable findings about the epidemiology of S. pneumoniae in Asian countries after the introduction of PCV7 were the high prevalence of macrolide resistance and MDR and distinctive increases in serotype 19A.
PMCID: PMC3294909  PMID: 22232285
4.  High Prevalence of Antimicrobial Resistance among Clinical Streptococcus pneumoniae Isolates in Asia (an ANSORP Study) 
A total of 685 clinical Streptococcus pneumoniae isolates from patients with pneumococcal diseases were collected from 14 centers in 11 Asian countries from January 2000 to June 2001. The in vitro susceptibilities of the isolates to 14 antimicrobial agents were determined by the broth microdilution test. Among the isolates tested, 483 (52.4%) were not susceptible to penicillin, 23% were intermediate, and 29.4% were penicillin resistant (MICs ≥ 2 mg/liter). Isolates from Vietnam showed the highest prevalence of penicillin resistance (71.4%), followed by those from Korea (54.8%), Hong Kong (43.2%), and Taiwan (38.6%). The penicillin MICs at which 90% of isolates are inhibited (MIC90s) were 4 mg/liter among isolates from Vietnam, Hong Kong, Korea, and Taiwan. The prevalence of erythromycin resistance was also very high in Vietnam (92.1%), Taiwan (86%), Korea (80.6%), Hong Kong (76.8%), and China (73.9%). The MIC90s of erythromycin were >32 mg/liter among isolates from Korea, Vietnam, China, Taiwan, Singapore, Malaysia, and Hong Kong. Isolates from Hong Kong showed the highest rate of ciprofloxacin resistance (11.8%), followed by isolates from Sri Lanka (9.5%), the Philippines (9.1%), and Korea (6.5%). Multilocus sequence typing showed that the spread of the Taiwan19F clone and the Spain23F clone could be one of the major reasons for the rapid increases in antimicrobial resistance among S. pneumoniae isolates in Asia. Data from the multinational surveillance study clearly documented distinctive increases in the prevalence rates and the levels of antimicrobial resistance among S. pneumoniae isolates in many Asian countries, which are among the highest in the world published to date.
PMCID: PMC415617  PMID: 15155207
5.  Serotyping of Streptococcus pneumoniae by Coagglutination with 12 Pooled Antisera 
Journal of Clinical Microbiology  1999;37(1):263-265.
We report on the performance of a recently introduced commercial chessboard method using 12 antisera, in comparison with that of the 55-antiserum panel used in determining the serogroups and types (SGTs) of Streptococcus pneumoniae, both of which were carried out by a coagglutination technique. Of a total of 150 strains of S. pneumoniae studied, 135 (90%) belonged to the SGTs represented in the 23-valent pneumococcal vaccine; of these, 130 (96.3%) were identified as the same SGTs by both typing methods. The remaining five strains showed cross-reactivity with more than two pools by the chessboard method, but could be assigned to a single SGT by the Quellung test. The 96.3% concordance of the chessboard method suggests it can be adopted for determination of the SGTs of S. pneumoniae in laboratories.
PMCID: PMC84232  PMID: 9854110
6.  PCR-Enzyme Immunoassay for Detection of Streptococcus pneumoniae DNA in Cerebrospinal Fluid Samples from Patients With Culture-Negative Meningitis 
Journal of Clinical Microbiology  1998;36(12):3605-3608.
A PCR-based assay was developed to amplify a conserved region of the pneumococcal autolysin gene. The amplified product was labelled with digoxigenin-labelled dUTP and was detected with a biotin-labelled probe in an enzyme immunoassay (EIA). The assay was initially tested with suspensions of various serotypes of Streptococcus pneumoniae and other gram-positive and gram-negative bacteria and was then applied to cerebrospinal fluid (CSF) specimens from patients with meningitis and those with other neurological disorders. The assay detected all the serotypes of S. pneumoniae tested, whereas all the other bacterial strains tested were negative. Seven of the 8 CSF specimens positive for pneumococcus by culture or latex agglutination (LA) were positive by PCR-EIA, whereas all 10 specimens positive for other organisms were negative. Among 11 patients with clinically diagnosed meningitis but with negative culture and LA results, 5 were positive by PCR-EIA. The assay was negative for all but one patient without meningitis; it was positive with the CSF from a child with immunodeficiency and pneumococcal abscesses on the scalp. PCR-EIA is a useful tool for the diagnosis of meningitis, especially when culture and LA are negative because of prior antibiotic treatment.
PMCID: PMC105248  PMID: 9817881
7.  Salmonella choleraesuis subsp. indica serovar bornheim causing urinary tract infection. 
Journal of Clinical Microbiology  1992;30(9):2504-2505.
An unusual Salmonella species, S. choleraesuis subsp. indica serovar bornheim, was isolated from the urine of a patient with aplastic anemia, diabetes mellitus, and a healed urethral injury. An immune response to this isolate was demonstrated by whole-bacterial-cell agglutination.
PMCID: PMC265536  PMID: 1401026
8.  Cerebral phaeohyphomycosis caused by Chaetomium globosum in a renal transplant recipient. 
Journal of Clinical Microbiology  1989;27(10):2226-2229.
A 32-year-old male patient developed headaches, vomiting, blurring of vision, and focal seizures of the left side of the face 2 months after a renal transplant. He developed a brain abscess and died. Direct KOH examination of the brain tissue demonstrated hyaline as well as dematiaceous, septate hyphae. Histologic examination of brain sections revealed polymorphous fungal elements consisting of septate, dark-pigmented hyphae, intercalary and terminal swollen fungal cells, and budding yeastlike cells characteristic of phaeohyphomycosis. Chaetomium globosum was isolated from the brain tissue on all of the fungal media used. This case represents the first histologically and culturally documented phaeohyphomycotic brain infection caused by C. globosum.
PMCID: PMC266999  PMID: 2584374
9.  Isolation of Acanthamoeba culbertsoni from a patient with meningitis. 
Journal of Clinical Microbiology  1985;21(4):666-667.
A case of amoebic meningitis, presumably primary, was encountered in the Christian Medical College Hospital, Vellore, South India, in November 1983. The patient, a 40-year-old man, had cerebrospinal fluid rhinorrhea before the meningitis developed. Acanthamoeba culbertsoni was repeatedly demonstrated in and cultured from the cerebrospinal fluid. The patient responded dramatically to a combination therapy of penicillin and chloramphenicol.
PMCID: PMC271748  PMID: 3988911
10.  Rapid screening of fecal samples for Vibrio cholerae by a coagglutination technique. 
Journal of Clinical Microbiology  1984;19(5):712-713.
A coagglutination procedure for detecting Vibrio cholerae was applied directly to 125 watery fecal samples received in the laboratory for bacteriological culture: many of these were from suspected cases of cholera. Of 47 bacteriologically proved cases of cholera, 44 (93.6%) gave positive results by the coagglutination method. There was a good correlation between the coagglutination method, dark-field microscopy, and culture.
PMCID: PMC271163  PMID: 6736229
11.  Immune response to Bacteroides ureolyticus in a patient with brain abscess. 
Journal of Clinical Microbiology  1983;18(2):428-429.
A high titer (1:256) of agglutinating antibodies against Bacteroides ureolyticus was demonstrated in a 35-year-old woman with brain abscess, using a microagglutination test. Tests done with B. ureolyticus and heterologous sera as well as with heterologous strains and the patient's serum were negative. Circulating antibody to B. ureolyticus has not been reported previously.
PMCID: PMC270819  PMID: 6619293

Results 1-11 (11)