A Streptococcus pneumoniae lineage usually associated with pneumococcal conjugate vaccine (PCV) serotypes is the most common cause of serotype 35B invasive disease in South Africa, following routine use of PCV.

Pneumococcal serotype 35B is an important non-conjugate vaccine (non-PCV) serotype. Its continued emergence, post-PCV7 in the USA, was associated with expansion of a pre-existing 35B clone (clonal complex [CC] 558) along with post-PCV13 emergence of a non-35B clone previously associated with PCV serotypes (CC156). This study describes lineages circulating among 35B isolates in South Africa before and after PCV introduction. We also compared 35B isolates belonging to a predominant 35B lineage in South Africa (GPSC5), with isolates belonging to the same lineage in other parts of the world. Serotype 35B isolates that caused invasive pneumococcal disease in South Africa in 2005-2014 were characterized by whole-genome sequencing (WGS). Multi-locus sequence types and global pneumococcal sequence clusters (GPSCs) were derived from WGS data of 63 35B isolates obtained in 2005-2014. A total of 262 isolates that belong to GPSC5 (115 isolates from South Africa and 147 from other countries) that were sequenced as part of the global pneumococcal sequencing (GPS) project were included for comparison. Serotype 35B isolates from South Africa were differentiated into seven GPSCs and GPSC5 was most common (49 %, 31/63). While 35B was the most common serotype among GPSC5/CC172 isolates in South Africa during the PCV13 period (66 %, 29/44), 23F was the most common serotype during both the pre-PCV (80 %, 37/46) and PCV7 period (32 %, 8/25). Serotype 35B represented 15 % (40/262) of GPSC5 isolates within the global GPS database and 75 % (31/40) were from South Africa. The predominance of the GPSC5 lineage within non-vaccine serotype 35B, is possibly unique to South Africa and warrants further molecular surveillance of pneumococci.

Nasopharyngeal carriage, antibiogram & serotype distribution of Streptococcus pneumoniae among healthy under five children.

BACKGROUND & OBJECTIVES: Information related to nasopharyngeal carriage of Streptococcus pneumoniae among healthy children is scanty in India. This prospective study was undertaken to determine the presence of asymptomatic nasopharyngeal colonization, assess serogroups/types (SGT) and drug resistance of S. pneumoniae in children below five years of age. METHODS: A total of 109 male and 81 female children in the age group of three months to five years belonging to different socio-economic classes were enrolled. They were recruited across all age groups from those attending paediatric OPD of a tertiary care and research centre for immunization program. Fifty three isolates identified as pneumococci were tested for their antimicrobial susceptibility pattern by Kirby-Bauer's disc diffusion and E-Test methods. Serotyping was performed by detection of the quelling reaction with specific antiserum. RESULT: The pneumococcal carriage rate in the study population was 27.9 per cent. The isolation rate was associated with age being higher (49.2%) in smaller children (3-12 months) and among male (62.2%). The most prevalent SGTs were 19 followed by 10, 14 and 7; 21 per cent of isolates belonging to serotype 10 (n=7) were 11 (n=4) were not covered in any of the conjugate vaccines currently available in Indian market. Resistance to co-trimoxazole, tetracycline, penicillin and erythromycin was observed in 91 per cent (n=48), 36 per cent (n=19), 17 per cent (n=9) and 9 per cent (n=5) isolates, respectively. All the penicillin resistant isolates were found to be intermediately resistant by E-Test. Multidrug resistance was observed in 19 per cent (n=10) isolates. INTERPRETATION & CONCLUSIONS: High level of antibiotic resistance was present in S. pneumoniae isolated from healthy children below age five. A pneumococcal conjugate vaccine with the prevailing SGTs would help to reduce the pool of antibiotic resistant pneumococci. Continued surveillance of serotypes and tracking susceptibility pattern of S. pneumoniae will help to introduce appropriate vaccination protocols.

Intestinal Cryptosporidiosis and the Profile of the CD4 Counts in a Cohort of HIV Infected Patients.

BACKGROUND: Cryptosporidium is an infectious enteric pathogen which is capable of causing life-threatening illnesses in immunocompromised patients. AIMS: This prospective study was planned to know the frequency of intestinal cryptosporidiosis in HIV infected patients and its correlation with their immune status. Also, the conventional diagnostic methods were compared with the copro-antigen detection test by using Enzyme Linked Immuno Sorbent Assay (ELISA). SETTINGS AND DESIGN: This was a prospective cohort study. METHODS AND MATERIAL: Three consecutive stool samples which were collected from 90 HIV seropositive patients and 50 seronegative controls were screened for cryptosporidiosis by wet mount, direct modified ZN (Ziehl Neelsen) staining, modified ZN staining with formol ether concentration and copro-antigen detection by ELISA. Their immune statuses were measured by CD4 + cell counting. Statistical Analytical Tests which were Used: Odds ratio, Chi square test, Fisher extract test. RESULTS: Cryptosporidiosis was detected in 15 HIV seropositive cases. 13 cases had CD4 cell counts of < 100 cells/ µL. The formol ether concentration technique resulted in an increased number of oocysts/oil immersion field in 8 cases. ELISA was positive in 2 cases which were shown to be negative by modified ZN staining. All the controls were negative for cryptosporidium. CONCLUSIONS: Cryptosporidiosis is an opportunistic infection in HIV infected people who present with diarrhoea. The wet mount technique, though it is simple and inexpensive, is insensitive for the detection of cryptosporidium. The conventional modified ZN staining and the modified ZN staining with concentration have a sensitivity and a specificity of 85.71% and 98.84% respectively. The copro antigen detection by ELISA which has a greater sensitivity and specificity, is a useful tool in epidemiological studies.

Circulating Serotypes and Trends in Antibiotic Resistance of Invasive Streptococcus Pneumoniae from Children under Five in Bangalore.

BACKGROUND: Globally, Streptococcus pneumoniae is estimated to be responsible for 1 to 2 million deaths annually, in extremes of age. Serotypic distribution of pneumococci varies with age, time, and geographical area. Limited data is available on serotypic prevalence and antimicrobial susceptibility patterns of pneumococci in India. AIM: To assess resistance trends to different groups of antimicrobials and serotypic prevalences of invasive pneumococci. SETTINGS AND DESIGN: A prospective, hospital based study was conducted for two years, at a tertiary care medical college hospital in south Bangalore. Forty invasive pneumococcal isolates from children who were ≤5 years, with a clinical and radiological diagnosis of invasive pneumococcal disease, (IPD) were evaluated. METHODS: Qualitative typing/grouping was performed by doing the capsular reaction test (Neufeld test). Antimicrobial susceptibility was tested by Minimum Inhibitory Concentration method using automated microdilution procedure. RESULTS: The predominant invasive pneumococcal serotypes were serogroups/types (SGTs) 6 (25%) and 14 (17.5%). 35%, 77.5% and 15% of isolates were resistant to Penicillin, Trimethoprim/Sulfamethoxazole (TMP-SMX) and Ceftriaxone respectively. Intermediate and high level resistances to penicillin were seen in 22.5% and 12.5% of S. pneumoniae isolates correspondingly. Multidrug resistance was observed in 20% of strains. CONCLUSION: This study reported presence of high level drug resistance in invasive pneumococcal isolates which were obtained from children. The serogroup/type distribution in our study and those in other Indian studies were not even. This calls for monitoring of resistance and mapping of serotype distribution.