Streptococcus agalactiae: Sensitivity profile in pregnant women attending health units in northeastern Brazil

BACKGROUND

Group B Streptococcus agalactiae (GBS) is the main etiologic agent associated with early-onset neonatal sepsis, and of all newborns of parturients colonized by GBS, approximately 1%-2% develop invasive, early-onset disease. The risk of infection increases to 15.2% in premature neonates, to 10.7% when the parturient has chorioamnionitis or premature rupture of membranes for more than 24 h and to 9.7% if the mother has postpartum bacteremia. In addition to causing perinatal, neonatal and postnatal deaths, neonatal hospital infection is associated with high costs, as hospitalization is three times longer than in uninfected children. The identification of pregnant women colonized by GBS, through universal screening, associated with the adoption of appropriate antibiotics at the time of delivery are the most successful preventive measures.

AIM

To evaluate the sensitivity profile of GBS isolated from pregnant women attending Vitória da Conquista-BA.

METHODS

This is a cross-sectional study with a quantitative approach carried out in the municipality of Vitória da Conquista-Bahia between February 2017 and March 2018. The study population was composed of 210 pregnant women, with a gestational age of 32 to 40 wk, who were aged 18 years or older living in the urban area of the municipality of Vitória da Conquista. After a brief explanation about the research and obtaining a signed an informed consent form, data and vaginorectal swabs were collected from the women for GBS research. Examination of the samples in order to identify the presence of GBS was by culture on sheep blood agar and chromogenic agar for GBS and then, seeded on plates containing streptococcal culture medium and incubated for 18 h to 24 h at 35°C. The antimicrobial sensitivity profile of positive GBS samples was determined by the disk diffusion technique, according to the Clinical and Laboratory Standards Institute manual (2017). The data obtained were stored in a database using Microsoft Office Excel spreadsheets and a descriptive analysis was performed with the aid of the EPI-INFO statistical package (version 3.5.2).

RESULTS

Among the 210 pregnant women participating in the study, 38 (18.1%) had a positive GBS culture. All strains isolated from GBS were sensitive to 10 U penicillin, 10 µg ampicillin, 30 µg cefotaxime and 30 µg vancomycin. Seven strains (18.4%) resistant to clindamycin 2 µg and eight (21.1%) resistant to erythromycin 15 µg were found. Of these, six were concomitantly resistant to erythromycin and clindamycin, two resistant only to erythromycin and one resistant only to clindamycin. All nine GBS isolates that showed resistance to erythromycin and/or clindamycin showed negative results on the D-test. Two thirds of the isolates showed cMLSB phenotype and resistance only to erythromycin in specimens in this study (02), refers to strains with phenotype M and resistance to clindamycin (01) only with phenotype L.

CONCLUSION

Chemoprophylaxis for GBS in pregnant women, especially for those allergic to penicillin, should be guided by an antimicrobial susceptibility test as resistant GBS strains were reported in this study.

Risk of triclosan based on avoidance by the shrimp Palaemon varians in a heterogeneous contamination scenario: How sensitive is this approach?

As the exposure of organisms to contaminants can provoke harmful effects, some organisms try to avoid a continuous exposure by using different strategies. The aim of the current study was to assess the ability of the shrimp Palaemon varians to detect a triclosan gradient and escape to less contaminated areas. Two multi-compartmented exposure systems (the linear system and the HeMHAS-Heterogeneous Multi-Habitat Assay System) were used and then results were compared. Finally, it was aimed how sensitive the avoidance response is by comparing it with other endpoints through a sensitivity profile by biological groups and the species sensitive distribution. The distribution of the shrimps along the triclosan gradient was dependent on the concentrations, not exceeding 3% for 54 μg/L in the linear system and 7% for 81 μg/L in the HeMHAS; 25% of organisms preferred the compartment with the lowest concentrations in both systems. Half of the population seems to avoid concentrations around 40-50 μg/L. The triclosan concentration that might start (threshold) to trigger an important avoidance (around 20%) was estimated to be of 18 μg/L. The profile of sensitivity to triclosan showed that avoidance by shrimps was less sensitive than microalgae growth and avoidance by guppy; however, it might occur even at concentrations considered safe for more than 95% of the species. In summary, (i) the HeMHAS proved to be a suitable system to simulate heterogeneous contamination scenarios, (ii) triclosan triggered the avoidance response in P. varians, and (iii) the avoidance was very sensitive compared to other ecotoxicological responses.

Reserve drug indent form and its impact on antimicrobial consumption and sensitivity pattern in the medical intensive care unit of a tertiary care hospital

OBJECTIVES

A world without effective antibiotics is a terrifying but a real prospect. Overuse or misuse especially of newer and higher antimicrobials (AM) is of particular concern, as this contributes to development of resistance among microorganisms. To check this trend, the Reserve Drug Indent Form (RDIF) was introduced in our hospital and its impact on AM consumption, cost of therapy and the sensitivity pattern was studied in the medical intensive care unit (MICU).

MATERIALS AND METHODS

A retrospective descriptive study in the medical ICU of a tertiary care hospital from July 2012 to August 2013. From March 2013, RDIF was made mandatory to be filled up prior to prescribing reserve antimicrobials. AM consumption (expressed as DDD/100 bed days) and sensitivity pattern (expressed in percentage) six months prior to and six months after implementation of the form were analysed.

RESULTS

The total Reserve AM consumption was 125.79 per 100 bed days during the study period. Average occupancy index was 0.50 and length of ICU stay was 6 days. The total consumption reduced from 85.55/100 to 40.24/100 bed days after the introduction of the RDIF. However, Imipenem usage increased from 11.35/100 to 23.94/100 bed days, which can be attributed to sensitivity profile to Imipenem (82.1%) compared to Meropenem (65.7%). Cost of therapy reduced from Rs 6,27,951 to 4,20,469.

CONCLUSION

Reserve AM consumption showed a declining trend after introduction of the RDIF. Hence, the RDIF served as an important tool to combat inappropriate use, reducing the cost burden and also helped to improve the sensitivity to reserve drugs.