Abu Tholib Aman

Effect of Cinnamon Oil on icaA Expression and Biofilm Formation by Staphylococcus epidermidis

ABSTRACT Staphylococcus epidermidis is notorious for its biofilm formation on medical devices, and novel approaches to prevent and kill S. epidermidis biofilms are desired. In this study, the effect of cinnamon oil on planktonic and biofilm cultures of clinical S. epidermidis isolates was evaluated. Initially, susceptibility to cinnamon oil in planktonic cultures was compared to the commonly used antimicrobial agents chlorhexidine, triclosan, and gentamicin. The MIC of cinnamon oil, defined as the lowest concentration able to inhibit visible microbial growth, and the minimal bactericidal concentration, the lowest concentration required to kill 99.9% of the bacteria, were determined using the broth microdilution method and plating on agar. A checkerboard assay was used to evaluate the possible synergy between cinnamon oil and the other antimicrobial agents. The effect of cinnamon oil on biofilm growth was studied in 96-well plates and with confocal laser-scanning microscopy (CLSM). Biofilm susceptibility was determined using a metabolic 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Real-time PCR analysis was performed to determine the effect of sub-MIC concentrations of cinnamon oil on expression of the biofilm-related gene, icaA. Cinnamon oil showed antimicrobial activity against both planktonic and biofilm cultures of clinical S. epidermidis strains. There was only a small difference between planktonic and biofilm MICs, ranging from 0.5 to 1% and 1 to 2%, respectively. CLSM images indicated that cinnamon oil is able to detach and kill existing biofilms. Thus, cinnamon oil is an effective antimicrobial agent to combat S. epidermidis biofilms.

Burden of Severe Rotavirus Diarrhea in Indonesia

Globally, rotavirus is the leading cause of diarrhea-related hospitalizations and deaths among young children, but the burden of rotavirus disease in Indonesia is poorly documented. From January through December 2006, we conducted prospective surveillance (inpatient and outpatient) among children aged <5 years at 6 hospitals in 6 provinces of Indonesia, using standardized methodology. Of 2240 enrolled children hospitalized for diarrhea, 1345 (60%) were rotavirus positive. Of 176 children enrolled in outpatient clinics in 3 hospitals, 73 (41%) were rotavirus positive. Among children hospitalized for diarrhea, dehydration was more common among those who tested positive for rotavirus than among those who did not (91% vs 82%; P < .05), as was vomiting (86% vs 67%; P < .05). Children aged 6-23 months experienced 72% of all rotavirus episodes. Rotavirus prevalence increased slightly in the cool, dry season. The most commonly detected genotypes were G9 (30%) and P[6] (56%). G1P[6] and G9P[6] accounted for 34% and 21% of strains, respectively. A high proportion of genotype P[6] was detected, in combination with the common G types G1 and G9. Available rotavirus vaccines would likely be efficacious against the most common circulating strains, but continued monitoring of uncommon genotypes is needed.

Ica-expression and gentamicin susceptibility of Staphylococcus epidermidis biofilm on orthopedic implant biomaterials.

Ica-expression by Staphylococcus epidermidis and slime production depends on environmental conditions such as implant material and presence of antibiotics. Here, we evaluate biofilm formation and ica-expression of S. epidermidis strains on biomaterials involved in total hip- and knee arthroplasty [polyethylene (PE), polymethylmethacrylate (PMMA), stainless steel (SS)]. Ica-expression, assayed using real-time RT-PCR, was highest on PE as confirmed using confocal laser scanning microscopy. Yet biofilm formation by S. epidermidis was most extensive on SS, with less slime production. Ica-expression and slime production were minimal on PMMA. After 3 h of continued growth of 24 h old biofilms in the presence of gentamicin, biofilms on PE showed lower susceptibility to gentamicin, relative to the other materials, presumably as a result of the stronger ica-expression. A higher gentamicin concentration further decreased metabolic activity on all biomaterials. It is concluded that the level of biomaterial-induced ica-expression does not correlate with the amount of biofilm formed, but initially aids bacteria in surviving antibiotic attacks. Once antibiotic treatment has started however, also the antibiotic itself induces slime production and only if its concentration is high enough, killing results. Results suggest that biomaterial-associated infections in orthopedics by S. epidermidis on PE may be more difficult to eradicate than on PMMA or SS.

recA mediated spontaneous deletions of the icaADBC operon of clinical Staphylococcus epidermidis isolates : a new mechanism of phenotypic variations

Phenotypic variation of Staphylococcus epidermidis involving the slime related ica operon results in heterogeneity in surface characteristics of individual bacteria in axenic cultures. Five clinical S. epidermidis isolates demonstrated phenotypic variation, i.e. both black and red colonies on Congo Red agar. Black colonies displayed bi-modal electrophoretic mobility distributions at pH 2, but such phenotypic variation was absent in red colonies of the same strain as well as in control strains without phenotypic variation. All red colonies had lost ica and the ability to form biofilms, in contrast to black colonies of the same strain. Real time PCR targeting icaA indicated a reduction in gene copy number within cultures exhibiting phenotypic variation, which correlated with phenotypic variations in biofilm formation and electrophoretic mobility distribution of cells within a culture. Loss of ica was irreversible and independent of the mobile element IS256. Instead, in high frequency switching strains, spontaneous mutations in lexA were found which resulted in deregulation of recA expression, as shown by real time PCR. RecA is involved in genetic deletions and rearrangements and we postulate a model representing a new mechanism of phenotypic variation in clinical isolates of S. epidermidis. This is the first report of S. epidermidis strains irreversibly switching from biofilm-positive to biofilm-negative phenotype by spontaneous deletion of icaADBC.

Identification of Rotavirus Strains Causing Diarrhoea in Children under Five Years of Age in Yogyakarta, Indonesian

BACKGROUND Rotavirus is an important cause of severe diarrhoea in children. The aims of this study were to identify the rotavirus strains that cause diarrhoea in children in Yogyakarta and to determine the association between rotavirus positivity and its clinical manifestations. METHODS Clinical data and stool samples were collected from children hospitalised at Kodya Yogyakarta Hospital, Indonesia. Rotavirus was detected in stool samples using an enzyme immunoassay (EIA), which was followed by genotyping using reverse transcriptase polymerase chain reaction (RT-PCR). Electropherotyping was performed for the rotavirus-positive samples. RESULTS In total, 104 cases were included in the study, 57 (54.8%) of which were rotavirus-positive. Based on a multiple logistic regression analysis, age group, vomiting and stool mucous were associated with rotavirus positivity. Most of the 56 samples subjected to genotyping were classified as G1 (80.36%) and P[8] (69.64%) genotypes. The genotype combination G1P[8] was identified as the most prevalent strain (66.07%). Of the 19 samples subjected to electropherotyping, 17 G1 isolates and 1 G3 isolate had long patterns, and 1 G1 isolate had a short pattern. CONCLUSION G1P[8] was the most dominant strain of rotavirus causing diarrhoea in children in Yogyakarta. Age group, vomiting and stool mucous were associated with rotavirus positivity.

Significance of continuous rotavirus and norovirus surveillance in Indonesia

BackgroundDiarrhea significantly contributes to the global burden of diseases, particularly in developing countries. Rotavirus and norovirus are the most dominant viral agents responsible for diarrheal disease globally. The aim of this review was to conduct a comprehensive assessment of rotavirus and norovirus study in Indonesia.Data sourcesArticles about rotavirus and norovirus surveillance in Indonesia were collected from databases, including PubMed and Google Scholar. Manual searching was performed to identify additional studies. Furthermore, relevant articles about norovirus diseases were included.ResultsA national surveillance of rotavirus-associated gastroenteritis has been conducted for years, resulting in substantial evidence about the high burden of the diseases in Indonesia. In contrast, norovirus infection received relatively lower attention and very limited data are available about the incidence and circulating genotypes. Norovirus causes sporadic and epidemic gastroenteritis globally. It is also emerging as a health problem in immunocompromised individuals. During post-rotavirus vaccination era, norovirus potentially emerges as the most frequent cause of diarrheal diseases.ConclusionsOur review identifies knowledge gaps in Indonesia about the burden of norovirus diseases and the circulating genotypes. Therefore, there is a pressing need to conduct national surveillance to raise awareness of the community and national health authority about the actual burden of norovirus disease in Indonesia. Continuing rotavirus surveillance is also important to assess vaccine effectiveness and to continue tracking any substantial changes of circulating rotavirus genotypes.

Emergence of Melioidosis in Indonesia and Today’s Challenges

A recent modeling study estimated that there could be as many as 20,000 human melioidosis cases per year in Indonesia, with around 10,000 potential deaths annually. Nonetheless, the true burden of melioidosis in Indonesia is still unknown. The Indonesia Melioidosis Network was formed during the first melioidosis workshop in 2017. Here, we reviewed 101 melioidosis cases (99 human and two animal cases) previously reported and described an additional 45 human melioidosis cases. All 146 culture-confirmed cases were found in Sumatra (n = 15), Java (n = 104), Kalimantan (n = 15), Sulawesi (n = 11) and Nusa Tenggara (n = 1). Misidentification of Burkholderia pseudomallei was not uncommon, and most cases were only recently identified. We also evaluated clinical manifestations and outcome of recent culture-confirmed cases between 2012 and 2017 (n = 42). Overall, 15 (36%) cases were children (age <15 years) and 27 (64%) were adults (age ≥15 years). The overall mortality was 43% (18/42). We conducted a survey and found that 57% (327/548) of healthcare workers had never heard of melioidosis. In conclusion, melioidosis is endemic throughout Indonesia and associated with high mortality. We propose that top priorities are increasing awareness of melioidosis amongst all healthcare workers, increasing the use of bacterial culture, and ensuring accurate identification of B. pseudomalleiand diagnosis of melioidosis.

Quality of Symptom-Based Diagnosis of Rotavirus Infection Based on Mathematical Modeling

Rotavirus is the leading cause of severe childhood gastroenteritis worldwide. The laboratory diagnosis requires testing of fecal specimens with commercial assays that often are not available in low resource settings. Therefore, estimation of rotavirus presence based on clinical symptoms is expected to improve the disease management without laboratory verification.

The Etiologies and Clinical Characteristics of Patients Hospitalized with an Acute Febrile Illness and Central Nervous System Sydromes in Indonesia

Abstract Background Acute febrile illness is a common reason for hospitalization in many developing countries, including Indonesia. While patients can often be categorized and managed based on clinical presentations, diagnostic capacity in these countries remains limited, leading to poor patient outcomes. For patients with central nervous system (CNS) infections, identifying the underlying etiologies is particularly important to prevent lifelong neurological complications and death. Methods As part of a study conducted at 8 top-referral hospitals across Indonesia from 2013 to 2016, 114 of 1,486 enrolled subjects presented with an acute fever and a CNS syndrome. To identify the etiologies and clinical manifestations of these infections, as well as the management of febrile patients at the hospitals, demographic and clinical data were collected at enrollment, and blood samples were collected for diagnostic testing at enrollment, once during days 14–28, and at 3 months after enrollment. Results Subject ages ranged from 1 to 63.2 years old (median of 4.9 years old), and underlying diseases were reported in 35 (30.7%) subjects. Standard-of-care, molecular, and serological testing identified pathogens in 56 (49.1%) cases, as detailed in the table. Of the 19 subjects who died, 18 presented with decreased consciousness and 5 were infected with Rickettsia typhi, which was clinically misdiagnosed in each case. Conclusion The findings from this study will improve the diagnosis and treatment of patients presenting with CNS syndromes in Indonesia. Additionally, the discovery of misdiagnosed, fatal etiologies highlights the general need for greater diagnostic testing capacity to aid clinicians and inform public health policy makers. Acute febrile patients with neurological signs and symptoms Consciousness status (n) Normal (61) Decreased (53) Mortality (%) 1.6 34 End-of-study status (n) Discharged (60) Died (1) Discharged (35) Died (18) Etiology (n) Unknown (32) Unknown (1) Unknown (16) Unknown (9) HHV-6 (9) Dengue (5) R. typhi (5) Dengue (8) HHV-6 (3) Dengue (1) Chikungunya (5) Influenza (2) Influenza (1) Influenza (3) E. faecalis (2) Salmonella spp. (1) K. pneumoniae 
(1) Chikungunya 
(1) S. pneumoniae 
(1) Amoeba (1) Leptospira spp. (1) S. Typhi (1) E. coli (1) S. Aureus (1) Seoul Virus (1) S.Typhi (1) RSV (1) Disclosures All authors: No reported disclosures.

INA-RESPOND: a multi-centre clinical research network in Indonesia

Nationally representative observational and translational research is needed to address the public health challenges in Indonesia due to the geographic disparity, recently decentralized health system, and diverse infectious disease priorities. To accomplish this, the Indonesian Ministry of Health in collaboration with the US National Institute of Health has established INA-RESPOND (Indonesia Research Partnership on Infectious Disease) – a clinical research network comprising 9 referral hospitals, 7 medical faculties, and 2 research centres across Indonesia. The network provides a forum to conduct research at a national scale and to address scientific questions that would be difficult to address in smaller research settings. Further, it is currently conducting multi-centre research on the etiologies of fever, sepsis, and tuberculosis. There are opportunities to leverage existing network resources for other public health research needs. INA-RESPOND is an Indonesian-led network in a country with diverse population groups and public health needs which is poised to collaborate with researchers, universities, donors, and industry worldwide. This paper describes the network and its goals and values, as well as the management structure, process for collaboration, and future vision.