No abstract

Haemophilus influenzae is a Gram-negative opportunistic bacterial pathogen of the human respiratory tract. This study describes the prevalence, serotype distribution, and susceptibility profiles of H. influenzae strains isolated from the nasopharynx of school children with acute otitis media (AOM) in Banyumas Regency, Central Java, Indonesia. H. influenzae was isolated from nasopharyngeal swab specimens using chocolate agar plates supplemented with IsoVitaleX and bacitracin. Serotyping was performed using quantitative polymerase chain reaction. Antimicrobial susceptibility profiles were determined using a microdilution broth assay. H. influenzae was present in 69.7% of samples (85/122). Nontypeable H. influenzae (NHTi) was the most common serotype (95.3%), followed by H. influenzae type b (3.5%) and H. influenzae type f (1.2%). All the H. influenzae isolates were susceptible to levofloxacin, ceftriaxone, imipenem, meropenem, cefuroxime, and cefixime. Most isolates were susceptible to sparfloxacin (99%), cefepime (99%), amoxicillin/clavulanic acid 2 : 1 (99%), ampicillin/sulbactam 2 : 1 (96%), chloramphenicol (94%), tetracycline (93%), ampicillin (87%), and clarithromycin (82%). Nineteen percent of the isolates were resistant to cotrimoxazole, and 11% of the isolates were resistant to ampicillin. This study showed that H. influenzae carriage among samples was dominated by NTHi and less susceptible to cotrimoxazole.

Streptococcus pneumoniae is a human pathogenic bacterium able to cause invasive pneumococcal diseases. Some studies have reported medicinal plants having antibacterial activity against pathogenic bacteria. However, antibacterial studies of medicinal plants against S. pneumoniae remains limited. Therefore, this study aims to describe the antibacterial activity of medicinal plants in Indonesia against S. pneumoniae. Medicinal plants were extracted by maceration with n-hexane, ethanol, ethyl acetate and water. Antibacterial activity was defined by inhibition zone and minimum inhibitory concentration (MIC). Bactericidal activity was measured by culture and time-killing measurement. Methods used to describe the mechanism of action of the strongest extract were done by absorbance at 595 nm, broth culture combined with 1% crystal violet, qRT-PCR targeting lytA, peZT and peZA, and transmission electron microscope to measure bacterial lysis, antibiofilm, LytA and peZAT gene expression, and ultrastructure changes respectively. Among 13 medicinal plants, L. inermis Linn. ethyl acetate extract showed the strongest antibacterial activity against S. pneumoniae with an MIC value of 0,16 mg/ml. Bactericidal activity was observed at 0,16 mg/ml for 1 hour incubation. Lawsonia inermis extract showed some mechanism of actions including bacterial lysis, antibiofilm, and ultrastructure changes such as cell wall disruption, decreasing cell membrane integrity and morphological disorder. Increasing of lytA and decreasing of peZA and peZT expression were also observed after incubation with the extract. In addition, liquid chromatography mass spectrophotometer showed phenolic compounds as the commonest compound in L. inermis ethyl acetate extract. This study describes the strong antibacterial activity of L. inermis with various mechanism of action including ultrastructure changes.

We investigated the resistance genes, pilus islet, biofilm formation ability, and sequence types of multidrug-resistant Streptococcus pneumoniae (MDRSP) isolated from the healthy children below 5 years of age in Indonesia. In all, 104 archived MDRSP isolates were screened for the presence of antibiotic resistance genes and  the rrgC  (pilus islet 1) and pitB (pilus islet 2) genes. Multilocus sequence typing and  biofilm formation was determined by DNA sequencing and the ability of cells to adhere to the walls respectively. Results have shown that the mefA, ermB, and tetM genes were found in 93%, 52%, and 100% of MDRSP isolates respectively. The insertion of arginine, proline, and Ile-100-Leu were the most common mutations in the folA and folP genes. Pilus islet 1 and type 2 were discovered in 93% and 82% of MDRSP isolates respectively. The MDRSP isolates showed no biofilm formation ability (64%) and  the most of sequence type was ST1464. This finding can be used to provide further considerations in implementing and monitoring pneumococcal vaccination in Indonesia.