Prevalence, antimicrobial susceptibility patterns, serotypes and risk factors for group B streptococcus rectovaginal isolates among pregnant women at Kenyatta National Hospital, Kenya; a cross-sectional study

BACKGROUND

Estimates of Group B Streptococcus (GBS) disease burden, antimicrobial susceptibility, and serotypes in pregnant women are limited for many resource-limited countries including Kenya. These data are required to inform recommendations for prophylaxis and treatment of infections due to GBS.

METHODS

We evaluated the prevalence, antimicrobial susceptibility patterns, serotypes, and risk factors associated with rectovaginal GBS colonization among pregnant women receiving antenatal care at Kenyatta National Hospital (KNH) between August and November 2017. Consenting pregnant women between 12 and 40 weeks of gestation were enrolled. Interview-administered questionnaires were used to assess risk factors associated with GBS colonization. An anorectal swab and a lower vaginal swab were collected and cultured on Granada agar for GBS isolation. Positive colonies were tested for antimicrobial susceptibility to penicillin G, ampicillin, vancomycin, and clindamycin using the disk diffusion method. Serotyping was performed by latex agglutination. Logistic regression was used to identify factors associated with GBS colonization.

RESULTS

A total of 292 women were enrolled. Median age was 30 years (Interquartile range {IQR} 26-35) and a median gestational age of 35 weeks (IQR 30-37). Overall GBS was identified in 60/292 (20.5%) of participants. Among the positive isolates, resistance was detected for penicillin G in 42/58 (72.4%) isolates, ampicillin in 32/58 (55.2%) isolates, clindamycin in 14/46 (30.4%) isolates, and vancomycin in 14/58 (24.1%) isolates. All ten GBS serotypes were isolated, and 37/53 (69.8%) of GBS positive participants were colonized by more than one serotype. None of the risk factors was associated with GBS colonization.

CONCLUSION

The prevalence of GBS colonization was high among antenatal women at KNH. In addition, a high proportion of GBS isolates were resistant to commonly prescribed intrapartum antibiotics. Hence, other measures like GBS vaccination is a potentially useful approaches to GBS prevention and control in this population. Screening of pregnant mothers for GBS colonization should be introduced and antimicrobial susceptibility test performed on GBS positive samples to guide antibiotic prophylaxis.

Polycyclic Aromatic Hydrocarbon Gaseous Emissions from Household Cooking Devices: A Kenyan Case Study

In developing countries, household energy use is highly variable and complex, yet emissions arising from fuel combustion indoors are typically poorly quantified. Polycyclic aromatic hydrocarbons (PAHs) are emitted during the combustion of organic fuels such as charcoal and biomass. In the present study, multichannel polydimethylsiloxane rubber traps were used for gas-phase PAH sampling and extracted using a low-solvent volume plunger-assisted solvent extraction method. Sixteen US Environmental Protection Agency priority PAHs, primarily in the gas phase, were investigated in indoor air of rural and urban residential homes in coastal Kenya (Mombasa and Taita Taveta Counties) using typical combustion devices of each area. Average gaseous PAH concentrations per household were higher in rural (ranging 0.81-6.09 µg m^-3 ) compared to urban (ranging 0-2.59 µg m^-3 ) homes, although ambient PAH concentrations were higher in urban environments, likely attributable to traffic contributions. The impact of fuel choice and thereby combustion device on PAH emissions was very clear, with the highest concentrations of PAHs quantified from wood-burning emissions from 3-stone stoves (total PAH averages 46.23 ± 3.24 µg m^-3 [n = 6]). Average benzo[a]pyrene equivalent total concentrations were evaluated for the priority PAHs and ranged from not detected to 43.31, 88.38, 309.61, and 453.88 ng m^-3 for gas, kerosene, jiko, 3-stone, and improved 3-stone stoves, respectively. Environ Toxicol Chem 2020;39:538-547. © 2019 SETAC.

A simple and fast Agrobacterium-mediated transformation system for passion fruit KPF4 (Passiflora edulis f. edulis × Passiflora edulis f. flavicarpa)

BACKGROUND

Passion fruit (Passiflora edulis Sims) is an important horticultural crop in the tropics and subtropics, where it has great commercial potential due to high demand for fresh edible fruits and processed juice as well as source of raw materials in cosmetic industries. Genetic engineering shows great potential in passion fruit improvement and can compensate for the limitations of conventional breeding. Despite the success achieved in genetic modification of few passion fruit varieties, transgenic passion fruit production is still difficult for farmer-preferred cultivars. Therefore, it is important to establish a simple and fast Agrobacterium-mediated cell transformation of commercial hybrid passion fruit KPF4 (Passiflora edulis f. edulis × Passiflora edulis f. flavicarpa).

RESULTS

In the present study, we have developed a simple and fast Agrobacterium-mediated transformation system for hybrid passion fruit KPF4 using leaf disc explants. Factors affecting the rate of transient beta (β)-glucuronidase (gusA) expression and consequently transformation efficiency were optimized as follows: Agrobacterium cell density with an OD₆₀₀ of 0.5, 30 min infection time, 3 days of co-cultivation duration and the incorporation of 200 µM acetosyringone into Agrobacterium infection suspension medium. Using the optimized conditions, transgenic plants of KPF4 were produced within 2 months with an average transformation efficiency of 0.67%. The β-glucuronidase (GUS) histochemical staining confirmed the expression and integration of an intron-containing gusA gene into transformed leaf discs and transgenic plant lines of KPF4. The presence of gusA gene in the transgenic plants was confirmed by polymerase chain reaction (PCR). The results confirmed that the gusA gene was efficiently integrated into the passion fruit genome.

CONCLUSIONS

The developed transformation protocol is simple and rapid and could be useful for functional genomic studies and transferring agronomically important traits into passion fruit hybrid KPF4. This study developed a method that can be used to transfer traits such as resistance to viral diseases, low fruit quality and short storage life. To the best of our knowledge, this is the first report on genetic transformation system for commercial passion fruit hybrid KPF4.