Prevalence and molecular epidemiology of Clostridium difficile infection in Thailand

Sample-to-result molecular diagnostic platforms and their suitability for infectious disease testing in low- and middle-income countries

INTRODUCTION

Diagnostics are an essential, undervalued part of the health-care system. For many diseases, molecular diagnostics are the gold standard, but are not easy to implement in Low- and Middle-Income Countries (LMIC). Sample-to-result (S2R) platforms combining all procedures in a closed system could offer a solution. In this paper, we investigated their suitability for implementation in LMIC.

AREAS COVERED

A scorecard was used to evaluate different platforms on a range of parameters. Most platforms scored fairly on the platform itself, ease-of-use and test consumables; however, shortcomings were identified in cost, distribution and test panels tailored to LMIC needs. The diagnostic coverage for common infectious diseases was found to have a wider coverage in high-income countries (HIC) than LMIC. A literature study showed that in LMIC, these platforms are mainly used as diagnostic tools or evaluation of diagnostic performance, with a minority assessing the operational characteristics or the clinical utility. In this narrative review, we identified various points for adaptation of S2R platforms to LMIC conditions.

EXPERT OPINION

For S2R platforms to be suitable for implementation in LMIC some modifications by the manufacturers could be considered. Furthermore, strengthening health systems and digitalization are vital; as are smaller, cheaper, faster, and sustainable technologies.

The burden of Clostridioides difficile infections in South-East Asia and the Western Pacific: A narrative review

BACKGROUND

Clostridioides difficile (formerly Clostridium difficile) is well-documented in Europe and North America to be a common cause of healthcare-associated gastrointestinal tract infections. In contrast, C difficile infection (CDI) is infrequently reported in literature from Asia, which may reflect a lack of clinician awareness. We conducted a narrative review to better understand CDI burden in Asia.

METHODS

We searched the PubMed database for English language articles related to C difficile, Asia, epidemiology, and molecular characteristics (eg, ribotype, antimicrobial resistance).

RESULTS

Fifty-eight articles that met eligibility criteria were included. C difficile prevalence ranged from 7.1% to 45.1 % of hospitalized patients with diarrhea, and toxigenic strains among all C difficile in these patients ranged from 68.2% to 91.9 % in China and from 39.0% to 60.0 % outside of China. Widespread C difficile ribotypes were RT017, RT014/020, RT012, and RT002. Recurrence in patients with CDI ranged from 3.0% to 17.2 %. Patients with CDI typically had prior antimicrobial use recently. High rates of resistance to ciprofloxacin, clindamycin, and erythromycin were frequently reported.

CONCLUSION

The regional CDI burden in Asia is still incompletely documented, seemingly due to low awareness and limited laboratory testing. Despite this apparent under recognition, the current CDI burden highlights the need for broader surveillance and for application of preventative measures against CDI in Asia.

Prevalence of Non-Toxigenic Clostridioides difficile in Diarrhoea Patients and Their Clinical Characteristics

Non-toxigenic Clostridioides difficile (NTCD) has been shown to decrease the risk of recurrent C. difficile infection (CDI) in patients following metronidazole or vancomycin treatment for CDI. Limited data on the prevalence of NTCD strains in symptomatic patients and their clinical characteristics are available. We conducted this study to investigate the prevalence of NTCD in diarrhoea patients and their clinical characteristics. Between July 2017 and June 2018, unduplicated stool specimens were collected from patients with diarrhoea. The characteristics and episodes of C. difficile infection in patients with NTCD and toxigenic strains were compared. Among the 1182 stool specimens collected, 236 (18.5%) were identified as growing C. difficile, and 19.5% of the identified isolates were found to be NTCD. Multivariate analysis showed that community-onset diarrhoea (OR = 4.13, 95% CI 1.07-15.97; p = 0.040), underlying diabetes (OR = 3.64, 95% CI 1.46-9.25; p = 0.006), previous use of glycopeptides (OR = 4.75, 95% CI 1.37-16.42; p = 0.014), and the lack of use of proton pump inhibitors (PPIs) (OR = 3.57, 95% CI 1.39-9.09; p = 0.009) were independently associated with the NTCD group. Although there was no statistical significance, the number of CDI episodes occurring after 90 days tended to be lower in the NTCD group (2.2%) than in the toxigenic group (11.2%). A considerable portion of the C. difficile strains isolated from patients with diarrhoea showed NTCD. Further, more extensive studies are needed to clearly define the protective effects of NTCD strains in patients with diarrhoea.

Challenges and future solutions for detection of Clostridioides difficile in adults

There are no established standards for the diagnosis of Clostridioides difficile infection (CDI), even though the importance of this infection in humans is well known. The effectiveness of the commercially available techniques, which are all standardized for use with human feces, is also limited in terms of the accuracy of the tests. Furthermore, the current approach lacks a point-of-care diagnosis with an acceptable range of sensitivity and specificity. This article reviews the challenges and possible future solutions for the detection of CDI in adults. Existing diagnostic methods, such as enzyme-linked immunoassays and microbial culturing for the detection of toxins A and B, appear to work poorly in samples but exhibit great sensitivity for glutamate dehydrogenase. Real-time polymerase chain reaction and nucleic acid amplification tests have been investigated in a few studies on human samples, but so far have shown poor turnaround times. Thus, developing a multiplex point-of-care test assay with high sensitivity and specificity is required as a bedside approach for diagnosing this emerging infection.

Insights into the Evolving Epidemiology of Clostridioides difficile Infection and Treatment: A Global Perspective

Clostridioides difficile remains an important public health threat, globally. Since the emergence of the hypervirulent strain, ribotype 027, new strains have been reported to cause C. difficile infection (CDI) with poor health outcomes, including ribotypes 014/020, 017, 056, 106, and 078/126. These strains differ in their geographic distribution, genetic makeup, virulence factors, and antimicrobial susceptibility profiles, which can affect their ability to cause disease and respond to treatment. As such, understanding C. difficile epidemiology is increasingly important to allow for effective prevention measures. Despite the heightened epidemiological surveillance of C. difficile over the past two decades, it remains challenging to accurately estimate the burden and international epidemiological trends given the lack of concerted global effort for surveillance, especially in low- and middle-income countries. This review summarizes the changing epidemiology of C. difficile based on available data within the last decade, highlights the pertinent ribotypes from a global perspective, and discusses evolving treatments for CDI.

Clostridioides (Clostridium) difficile in adults with diarrhoea in Vietnam

BACKGROUND

Clostridioides (Clostridium) difficile causes antimicrobial-associated diarrhoea, however, presentations may range from asymptomatic carriage to severe diarrhoea, life-threatening toxic megacolon and even death. Reports on C. difficile infection (CDI) in Vietnam remain limited. The objectives of this study were to evaluate the epidemiology, molecular characteristics, and antimicrobial susceptibility of C. difficile isolated from adults with diarrhoea in Vietnam.

METHODS

Diarrhoeal stool samples from adult patients aged ≥17 years old were collected at Thai Binh General Hospital in northern Vietnam between 1^st March 2021 and 28th February2022. All samples were transported to The University of Western Australia, Perth, Western Australia for C. difficile culture, toxin gene profiling, PCR ribotyping and antimicrobial susceptibility testing.

RESULTS

A total of 205 stool samples were collected from patients aged from 17 to 101 years old. The overall prevalence of C. difficile was 15.1% (31/205) with the recovery of toxigenic and non-toxigenic isolates 9.8% (20/205) and 6.3% (13/205), respectively. Thus 33 isolates were recovered comprising 18 known ribotypes (RTs) and one novel RT (two samples contained two different RTs in each sample). The most prevalent strains were RT 012 (five strains) and RTs 014/020, 017 and QX 070 three strains each. All C. difficile were susceptible to amoxicillin/clavulanate, fidaxomicin, metronidazole, moxifloxacin and vancomycin, while resistance to varying degrees was seen to clindamycin, erythromycin, tetracycline and rifaximin, 78.8% (26/33), 51.5% (17/33), 27.3% (9/33) and 6.1% (2/33), respectively. The prevalence of multidrug resistance was 27.3% (9/33) and multidrug resistance was most common in toxigenic RT 012 and non-toxigenic RT 038 strains.

CONCLUSION

The prevalence of C. difficile in adults with diarrhoea and multidrug resistance in C. difficile isolates was relatively high. A clinical assessment to differentiate between CDI/disease and colonisation is required.

Novel ribotype/sequence type associations and diverse CRISPR-Cas systems in environmental Clostridioides difficile strains from northern Iraq

The environment is a natural reservoir of Clostridioides difficile, and here, we aimed to isolate the pathogen from seven locations in northern Iraq. Four of the sites yielded thirty-one isolates (ten from soils, twenty-one from sediments), which together represent ribotypes (RTs) 001 (five), 010 (five), 011 (two), 035 (two), 091 (eight), and 604 (nine). Twenty-five of the isolates (∼81%) are non-toxigenic, while six (∼19%) encode the toxin A and B genes. The genomes of eleven selected isolates represent six sequence types (STs): ST-3 (two), ST-15 (one), ST-107 (five), ST-137 (one), ST-177 (one), and ST-181 (one). Five novel RT/ST associations: RT011/ST-137, RT035/ST-107, RT091/ST-107, RT604/ST-177, and RT604/ST-181 were identified, and the first three are linked to RTs previously uncharacterized by multilocus sequence typing (MLST). Nine of the genomes belong to Clade 1, and two are closely related to the cryptic C-I clade. Diverse multiple prophages and CRISPR-Cas systems (class 1 subtype I-B1 and class 2 type V CRISPR-Cas systems) with spacers identical to other C. difficile phages and plasmids were detected in the genomes. Our data show the broader diversity that exists within environmental C. difficile strains from a much less studied location and their potential role in the evolution and emergence of new strains.

Epidemiology of Clostridium (Clostridioides) difficile Infection in Southeast Asia

This review describes the current understanding of Clostridium (Clostridioides) difficile infection (CDI) in southeast Asia regarding the prevalence of CDI, C. difficile detection methods, antimicrobial susceptibility profiles, and the potential significance of a One Health approach to prevention and control. Our initial focus had been the Indochina region, however, due to limited studies/surveillance of CDI in Indochina, other studies in southeast Asian countries and neighboring Chinese provinces are presented here for comparison. Clostridium (Clostridioides) difficile infection is one of the most common causes of hospital-acquired gastroenteritis worldwide. Since its discovery as a cause of pseudomembranous colitis in 1978, C. difficile-related disease has been more prevalent in high-income rather than low-income countries. This may be because of a lack of knowledge and awareness about the significance of C. difficile and CDI, resulting in underreporting of true rates. Moreover, the abuse of antimicrobials and paucity of education regarding appropriate usage remain important driving factors in the evolution of CDI worldwide. The combination of underreporting of true CDI rates, along with continued misuse of antimicrobial agents, poses an alarming threat for regions like Indochina. C. difficile ribotype (RT) 027 has caused outbreaks in North America and European countries, however, C. difficile RT 017 commonly occurs in Asia. Toxin A-negative/toxin B-positive (A-B+) strains of RT 017 have circulated widely and caused outbreaks throughout the world and, in southeast Asia, this strain is endemic.

Loop mediated isothermal amplification of Clostridioides difficile isolates in gastrointestinal patients

This study investigated the prevalence of Clostridioides difficile by culture, multiplex polymerase chain reaction (M-PCR), and loop mediated isothermal amplification (LAMP) in patients with suspected C. difficile infections (CDIs). Also, the results of three methods were compared. All stool specimens collected from CDI suspected patients were cultured on selective C. difficile cycloserine-cefoxitin fructose agar and incubated in an anaerobic jar up to 7 days. The bacterial isolates were identified using standard tests. Multiplex-PCR (M-PCR) was performed for detection of tcdA, tcdB, and tpi genes. The LAMP assay was performed to detect the tcdB gene of C. difficile. C. difficile was isolated from 20.0% (n = 10/50) of samples by culture. M-PCR showed that 34.0% (n = 17/50) of the specimens were positive for C. difficile based on the presence of tpi gene. Out of the 17 C. difficile, 13 strains (76.0%) were positive for tcdB gene using M-PCR. However, the LAMP assay showed that 30.0% (15/50) of specimens were positive for the presence of tcdB gene. M-PCR and LAMP methods showed 100.0% sensitivity compared to the culture method. However, the specificity of the LAMP (87.5%) was relatively higher than the M-PCR (82.5%) compared to the culture. Based on the results of this study, the prevalence of toxigenic C. difficile strains was high in suspected CDI patients. So, the differentiation between toxigenic and non-toxigenic strains is necessary. Our data showed that the LAMP assay is a good method for direct detection of toxigenic C. difficile strains from stool specimens.

Clostridioides difficile epidemiology in the Middle and the Far East

OBJECTIVES

Clostridioides difficile is an important pathogen of healthcare-associated gastrointestinal infections. Recently, an increased number of C. difficile infection (CDI) surveillance data has been reported from Asia. The aim of this review is to summarize the data on the prevalence, distribution and molecular epidemiology of CDI in the Middle and the Far East.

METHODS

Literature was drawn from a search of PubMed up to September 30, 2021.

RESULTS

The meta-analysis of data from 111 studies revealed the pooled CDI prevalence rate in the Middle and the Far East of 12.4% (95% CI 11.4-13.3); 48 studies used PCR for CDI laboratory diagnoses. The predominant types (RT)/sequence type (ST) differ between individual countries (24 studies, 14 countries). Frequently found RTs were 001, 002, 012, 017, 018 and 126; RT017 was predominant in the Far East. The epidemic RT027 was detected in 8 countries (22 studies), but its predominance was reported only in three studies (Israel and Iran). The contamination of vegetable and meat or meat products and/or intestinal carriage of C. difficile in food and companion animals have been reported; the C. difficile RTs/STs identified overlapped with those identified in humans.

CONCLUSIONS

A large number of studies on CDI prevalence in humans from the Middle and the Far East have been published; countries with no available data were identified. The number of studies on C. difficile from non-human sources is limited. Comparative genomic studies of isolates from different sources are needed.

Clostridioides (Clostridium) difficile in children with diarrhoea in Vietnam

BACKGROUND

Clostridioides (Clostridium) difficile commonly causes hospital-acquired infection which can range from mild diarrhoea to life-threatening toxic megacolon and even death. Reports on C. difficile infection (CDI) in Vietnam are limited, so this study was designed to evaluate the prevalence, molecular epidemiology and antimicrobial susceptibility of C. difficile isolated from children with diarrhoea in Vietnam. Infants are often colonised with C. difficile and it was hypothesised that those colonising strains would represent strains of C. difficile circulating in the hospital/region at the time, however, this was not an attempt to determine if C. difficile was the cause of the diarrhoea.

METHODS

Diarrhoeal stool samples collected at two children's hospitals in northern Vietnam from 1^st October 2020 to 28^th February 2021 were transported to Perth, Western Australia, for culture of C. difficile and further investigations on isolates; PCR ribotyping, toxin gene profiling and antimicrobial susceptibility testing.

RESULTS

From these hospitals, 370 diarrhoeal stool samples were collected, most from children aged 1-15 months (71.9%; 266/370). The overall prevalence of C. difficile in stool samples from children aged ≤16 years was 37.8% (140/370) and the highest prevalence was in the 2-12 months age group (52.9%; 74/140). In total, 151 isolates of C. difficile were recovered; the proportion of toxigenic isolates was 16.6% (25/151). Of the 25 toxigenic C. difficile isolates, the toxin gene profiles A⁺B⁺CDT^- and A^-B⁺CDT^- comprised 72% and 28%, respectively. The four most prevalent C. difficile ribotypes (RTs) were QX 011 (25/151), RT 010 (25/151), QX 107 (12/151) and RT 012 (11/151). All isolates were susceptible to vancomycin, metronidazole and fidaxomicin, while there was significant resistance to clindamycin (90.1%), and some to moxifloxacin (6.6%) and rifaximin (3.3%).

CONCLUSION

The prevalence of C. difficile in children with diarrhoea was high (37.8%) although the proportion of toxigenic strains was comparatively low. The clinical significance of any isolate needs to be determined.

Global evolutionary dynamics and resistome analysis of Clostridioides difficile ribotype 017

Clostridioides difficile PCR ribotype (RT) 017 ranks among the most successful strains of C. difficile in the world. In the past three decades, it has caused outbreaks on four continents, more than other ‘epidemic’ strains, but our understanding of the genomic epidemiology underpinning the spread of C. difficile RT 017 is limited. Here, we performed high-resolution phylogenomic and Bayesian evolutionary analyses on an updated and more representative dataset of 282 non-clonal C. difficile RT 017 isolates collected worldwide between 1981 and 2019. These analyses place an estimated time of global dissemination between 1953 and 1983 and identified the acquisition of the ermB-positive transposon Tn6194 as a key factor behind global emergence. This coincided with the introduction of clindamycin, a key inciter of C. difficile infection, into clinical practice in the 1960s. Based on the genomic data alone, the origin of C. difficile RT 017 could not be determined; however, geographical data and records of population movement suggest that C. difficile RT 017 had been moving between Asia and Europe since the Middle Ages and was later transported to North America around 1860 (95 % confidence interval: 1622–1954). A focused epidemiological study of 45 clinical C. difficile RT 017 genomes from a cluster in a tertiary hospital in Thailand revealed that the population consisted of two groups of multidrug-resistant (MDR) C. difficile RT 017 and a group of early, non-MDR C. difficile RT 017. The significant genomic diversity within each MDR group suggests that although they were all isolated from hospitalized patients, there was probably a reservoir of C. difficile RT 017 in the community that contributed to the spread of this pathogen.

Temporal Variations in Patterns of Clostridioides difficile Strain Diversity and Antibiotic Resistance in Thailand

Clostridioides difficile has been recognized as a life-threatening pathogen that causes enteric diseases, including antibiotic-associated diarrhea and pseudomembranous colitis. The severity of C. difficile infection (CDI) correlates with toxin production and antibiotic resistance of C. difficile. In Thailand, the data addressing ribotypes, toxigenic, and antimicrobial susceptibility profiles of this pathogen are scarce and some of these data sets are limited. In this study, two groups of C. difficile isolates in Thailand, including 50 isolates collected from 2006 to 2009 (THA group) and 26 isolates collected from 2010 to 2012 (THB group), were compared for toxin genes and ribotyping profiles. The production of toxins A and B were determined on the basis of toxin gene profiles. In addition, minimum inhibitory concentration of eight antibiotics were examined for all 76 C. difficile isolates. The isolates of the THA group were categorized into 27 A⁻B⁺CDT⁻ (54%) and 23 A^-B^-CDT^- (46%), while the THB isolates were classified into five toxigenic profiles, including six A⁺B⁺CDT⁺ (23%), two A⁺B⁺CDT⁻ (8%), five A⁻B⁺CDT⁺ (19%), seven A⁻B⁺CDT⁻ (27%), and six A⁻B⁻CDT⁻ (23%). By visually comparing them to the references, only five ribotypes were identified among THA isolates, while 15 ribotypes were identified within THB isolates. Ribotype 017 was the most common in both groups. Interestingly, 18 unknown ribotyping patterns were identified. Among eight tcdA-positive isolates, three isolates showed significantly greater levels of toxin A than the reference strain. The levels of toxin B in 3 of 47 tcdB-positive isolates were significantly higher than that of the reference strain. Based on the antimicrobial susceptibility test, metronidazole showed potent efficiency against most isolates in both groups. However, high MIC values of cefoxitin (MICs 256 μg/mL) and chloramphenicol (MICs ≥ 64 μg/mL) were observed with most of the isolates. The other five antibiotics exhibited diverse MIC values among two groups of isolates. This work provides evidence of temporal changes in both C. difficile strains and patterns of antimicrobial resistance in Thailand.

Prevalence of Clostridium difficile and its toxins in hospital patients with diarrhoeal diseases in Lusaka, Zambia

BACKGROUND

Clostridium difficile infection (CDI) has emerged as an important nosocomial and antibiotic-associated diarrhoeal problem leading to increasing morbidity and mortality, especially in resource-privileged regions. CDI varies in incidence, pathogenicity and risk factors across geographical locations, yet little information is available on CDI in sub-Saharan Africa. This study aimed to determine the prevalence of Clostridium difficile and related toxin expression in stool specimens from patients with diarrhoeal disease at the University Teaching Hospital, Lusaka, Zambia.

METHODS

Between June and September 2017, patients presenting with acute or persistent diarrhoea provided stool samples that were cultured anaerobically on cycloserine cefoxitin fructose agar. Isolates were identified by Gram staining, C. difficile latex agglutination and confirmed by PCR targeting of the tpi housekeeping gene. Toxins A or B were detected by ELISA.

RESULTS

Of 135 participants enrolled, 13 (10%) were C. difficile positive, of which four (31%) were toxigenic by ELISA. Among HIV-positive and HIV-negative participants, the frequency of culturable C. difficile (19% vs 12%; p=0.17) and of toxigenic isolates (15% vs 0%, p=0.19) did not differ.

CONCLUSIONS

We can now revise previous research and confirm that CDI contributes to diarrhoea among hospitalised adult patients irrespective of HIV status.

Molecular Characterization of, and Antimicrobial Resistance in, Clostridioides difficile from Thailand, 2017-2018

Antimicrobial resistance (AMR) plays an important role in the pathogenesis and spread of Clostridioides difficile infection (CDI). Many antimicrobials, such as fluoroquinolones, have been associated with outbreaks of CDI globally. This study characterized AMR among clinical C. difficile strains in Thailand, where antimicrobial use remains inadequately regulated. Stool samples were screened for tcdB and positives were cultured. C. difficile isolates were characterized by toxin profiling and PCR ribotyping. Antimicrobial susceptibility testing was performed by agar incorporation, and whole-genome sequencing and AMR genotyping were performed on a subset of strains. There were 321 C. difficile strains isolated from 326 stool samples. The most common toxigenic ribotype (RT) was RT 017 (18%), followed by RTs 014 (12%) and 020 (7%). Resistance to clindamycin, erythromycin, moxifloxacin, and rifaximin was common, especially among RT 017 strains. AMR genotyping revealed a strong correlation between resistance genotype and phenotype for moxifloxacin and rifaximin. The presence of erm-class genes was associated with high-level clindamycin and erythromycin resistance. Point substitutions in the penicillin-binding proteins were not sufficient to confer meropenem resistance, but a Y721S substitution in PBP3 was associated with a 4.37-fold increase in meropenem minimal inhibitory concentration. No resistance to metronidazole, vancomycin, or fidaxomicin was observed.

Clostridioides difficile colonization and infection in a cohort of Australian adults with cystic fibrosis

BACKGROUND

Little is known about Clostridioides difficile infection (CDI) in patients with cystic fibrosis (CF). The aim of this study was to investigate the prevalence, molecular epidemiology and risk factors for CDI in asymptomatic and symptomatic adults with CF in Western Australia.

METHODS

Faecal samples from symptomatic and asymptomatic patients were prospectively collected and tested for the presence of C. difficile by toxigenic culture. Ribotyping was performed by established protocols. Logistic regression analysis was performed to analyse the risk factors for C. difficile colonization and infection. Extensive environmental sampling was performed within the CF clinic in Perth.

RESULTS

The prevalence rates of asymptomatic toxigenic and non-toxigenic C. difficile colonization were 30% (14/46 patients) and 24% (11/46 patients), respectively. Fifteen ribotypes (RTs) of C. difficile were identified, of which non-toxigenic RT 039 was the most common. Among the symptomatic patients, the prevalence of toxigenic CDI was 33% (11/33 patients). Impaired glucose tolerance/diabetes mellitus and duration of intravenous antibiotic use in the past 12 months were significantly associated with increased risk of asymptomatic toxigenic C. difficile carriage and CDI. A trend towards higher CF transmembrane conductance regulator modulator treatment was observed in the CDI group. Extensive environmental sampling showed no evidence of toxigenic C. difficile contamination within the CF clinic.

CONCLUSIONS

A high prevalence of asymptomatic carriage of toxigenic C. difficile was observed in adults with CF, comparable with that observed in the symptomatic CF population. There was no evidence of direct person-to-person transmission.

Clostridioides difficile ribotypes 001 and 126 were predominant in Tehran healthcare settings from 2004 to 2018: a 14-year-long cross-sectional study

Clostridioides difficile infection (CDI) remains a major healthcare problem worldwide, however, little is known about CDI epidemiology in Iran. Between December 2004 and November 2018, 3649 stool samples were collected from patients in 69 hospitals and medical centres in Tehran and were cultured for the presence of C. difficile; isolates were characterized by PCR ribotyping and toxin genes detection. A total of 582 C. difficile isolates were obtained and the overall CDI prevalence was 15.9%; 290 (49.8%) cases were healthcare-associated (HA) and 292 (50.2%) cases were community-associated (CA). Of these, DNA of 513 isolates submitted for ribotyping. The ribotype and/or WEBRIBO type could be assessed in 366 (62.9%) isolates. The most frequent RTs were 001 (n = 75, 12.9%), 126 (n = 65, 11.2%) and 084 (n = 19, 3.3%); the toxin gene profile tcdA ⁺ B ⁺ /cdtA ⁺ B ⁺ (n = 112, 19.2%) was the most common. Fifteen C. difficile isolates (2.6%) did not carry any toxin genes. There was no difference between frequently found RTs in HA-CDI and CA-CDI, except for RT 029 which was more likely to be associated with healthcare origin (12/15, p-value = 0.02). No isolate of RTs 027 or 078 was identified. Importantly, RTs 031, 038, 039, 084, 085 reported previously as RTs with an absence of toxin genes, revealed the presence of toxin genes in our study. Using Simpson's reciprocal index of diversity, we found that RT diversity decreased as the prevalence of the RT 084 increased (R = -0.78, p-value = 0.041). Different patterns in CDI epidemiology underscore the importance of local surveillance and infection control measures in Tehran healthcare settings.

Genomic basis of antimicrobial resistance in non-toxigenic Clostridium difficile in Southeast Asia

Despite being incapable of causing Clostridium difficile infection, non-toxigenic C. difficile (NTCD) may still be relevant. This study explored the role of NTCD as a reservoir of accessory antimicrobial resistance (AMR) genes in NTCD from Southeast Asia. This region has high rates of antimicrobial use, a high prevalence of NTCD and phenotypic AMR in such strains. More than half of the 28 NTCD strains investigated had at least one accessory AMR gene on mobile genetic elements (MGEs) which were similar to the elements found in other bacteria, including Erysipelothrix rhusiopathiae and Streptococcus suis, both of which are found in the pig gut. Thus, C. difficile may facilitate the movement of AMR genes between different hosts within a wide range of pathogenic bacteria. C. difficile β-lactamases were not located on MGEs and were unlikely to be transferred. Concordance between the MLS_B resistance genotype and phenotype was low, suggesting multiple resistance mechanisms, many of which remain unknown. On the contrary, there was a high concordance between resistance genotype and phenotype for both fluoroquinolones and rifaximin. From an epidemiological perspective, NTCD populations in Southeast Asia comprised members of evolutionary clades 1 and 4, which are thought to have originated from Europe and Asia, respectively. This population structure reflects the close relationship between the people of the two regions.

Prevention of Clostridioides difficile in hospitals: A position paper of the International Society for Infectious Diseases

Clostridioides difficile infection is an increasing presence worldwide. Prevention is multipronged, reflecting a complex and evolving epidemiology. Multiple guidelines exist regarding the prevention of C. difficile infection in healthcare settings; however, existing guidelines do not address C. difficile in low- and middle-income countries (LMIC). Nevertheless, the prevalence of C. difficile in LMIC likely parallels, if not exceeds, that of high-income countries, and LMIC may experience additional challenges in C. difficile diagnosis and control. A panel of experts was convened by the International Society for Infectious Diseases (ISID) to review the current state of C. difficile infections globally and make evidence-based recommendations for infection prevention that are broadly applicable.

Mild or Malign: Clinical Characteristics and Outcomes of Clostridium difficile Infection in Thailand

Little is known about the clinical characteristics of Clostridium difficile infection (CDI) in Asia in general, and Thailand specifically, with a few studies suggesting that the disease may be milder than elsewhere. This study aimed to describe CDI in Thailand, evaluate treatment options and their outcomes, and explore possible protective factors responsible for any unique disease characteristics. From 2015 to 2018, 469 patients were included in the study. All patients had their stools tested for the tcdB gene by direct PCR and detection of toxigenic C. difficile by culture. C. difficile isolates were subjected to toxin gene profiling and ribotyping, and patient medical records were reviewed retrospectively. There were 248 and 221 patients included in CDI and control groups, respectively. The CDI group had a higher overall 30-day mortality rate than the control group (21% versus 14%, P = 0.046), but only 2 deaths (1%) were directly attributable to CDI. Metronidazole treatment was not inferior to vancomycin in this population, and vancomycin was associated with a higher 30-day mortality rate (P = 0.047). The prevalence of severe CDI and disease outcomes were not different between patients infected with A-B+ C. difficile and A+B+ C. difficile strains or between patients with and without colonization by nontoxigenic C. difficile Besides C. difficile-specific tests, neither a single laboratory result nor a combination of results was predictive of CDI. In conclusion, CDI in Thailand was relatively mild, and metronidazole remained an effective treatment option for these mild infections.

Antimicrobial Susceptibilities of Clostridium difficile Isolates from 12 Asia-Pacific Countries in 2014 and 2015

Clostridium (Clostridioides) difficile causes toxin-mediated diarrhea and pseudomembranous colitis, primarily among hospital inpatients. Outbreaks of C. difficile infection (CDI) have been caused by strains with acquired antimicrobial resistance, particularly fluoroquinolone resistance, including C. difficile ribotype (RT) 027 in North America and Europe and RT 017, the most common strain in Asia. Despite being the most common cause of hospital-acquired infection in high-income countries, and frequent misuse of antimicrobials in Asia, little is known about CDI in the Asia-Pacific region. We aimed to determine the antimicrobial susceptibility profiles of a collection of C. difficile isolates from the region. C. difficile isolates (n = 414) from a 2014 study of 13 Asia-Pacific countries were tested for susceptibility to moxifloxacin, amoxicillin-clavulanate, erythromycin, clindamycin, rifaximin, metronidazole, vancomycin, and fidaxomicin according to the Clinical and Laboratory Standards Institute's agar dilution method. All isolates were susceptible to metronidazole, vancomycin, amoxicillin-clavulanate, and fidaxomicin. Moxifloxacin resistance was detected in all countries except Australia, all RT 369 and QX 239 strains, and 92.7% of RT 018 and 70.6% of RT 017 strains. All C. difficile RT 012, 369, and QX 239 strains were also resistant to erythromycin and clindamycin. Rifaximin resistance was common in RT 017 strains only (63.2%) and was not detected in Australian, Japanese, or Singaporean isolates. In conclusion, antimicrobial susceptibility of C. difficile varied by strain type and by country. Multiresistance was common in emerging RTs 369 and QX 239 and the most common strain in Asia, RT 017. Ongoing surveillance is clearly warranted.

Prevalence, toxin gene profile, genotypes and antibiotic susceptibility of Clostridium difficile in a tertiary care hospital in Taif, Saudi Arabia

Purpose

Clostridium difficile (C. difficile) is an important causative agent of nosocomial diarrhoea and has become a major worldwide public health concern. The current study was conducted to determine the prevalence of C. difficile infection (CDI) amongst patients with nosocomial diarrhoea in a large tertiary care hospital in Taif, Saudi Arabia, and to define molecular characteristics and antimicrobial sensitivity profiles of C. difficile strains isolated from those patients.

Materials and Methods

Stool specimens were collected from 456 patients and were cultured for C. difficile isolation. The isolates were subjected to multiplex polymerase chain reaction (PCR) for detecting genes encoding the toxins (toxin A, toxin B and binary toxin [CDT]), genotyping by PCR ribotyping method and antimicrobial sensitivity testing using E test strips.

Results

Seventy-four C. difficile strains were recovered, of which 44 (59.5%) were A+B+CDT-, 14 (18.9%) were A-B+CDT-, 4 (5.4%) were A+B+CDT+ and 12 (16.2%) were A-B-CDT-. Toxigenic strains, and hence CDI, were detected in 13.6% of the patients (62/456). Fourteen different ribotypes were distinguished amongst bacterial isolates, of which ribotypes 002, 001, 017, 014 and 020 were the most prevalent (20.3%, 18.9%, 18.9%, 9.5% and 8.1%, respectively). Four isolates (5.4%) belonged to ribotype 027. All bacterial isolates showed sensitivity to metronidazole, vancomycin and piperacillin-tazobactam. The isolates exhibited resistance to linezolid (2.7%), chloramphenicol (5.4%), rifampicin (13.5%), tetracycline (21.6%), moxifloxacin (48.6%), clindamycin (54%) and imipenem (83.8%). Multiple drug resistance was observed in 56.8% of the isolates.

Conclusion

Further larger studies are required for an accurate understanding of CDI epidemiology in Saudi Arabia.

Clostridioides difficile infection in the Asia-Pacific region

Clostridioides difficile causes healthcare-related diarrhoea in high-income countries. Highly resistant spores persist in healthcare facilities, primarily infecting patients who have recently received antimicrobials. C. difficile infection (CDI) has been studied in detail in North America and Europe; however, the epidemiology of CDI elsewhere, including the Asia-Pacific region, is largely unknown. A survey of CDI was performed in 13 Asia-Pacific countries. Epidemiological data on 600 cases were collected and molecular typing undertaken on 414 C. difficile isolates. Healthcare facility-associated CDI comprised 53.6% of cases, while community-associated CDI was 16.5%. The median age of cases was 63.0 years and 45.3% were female, 77.5% had used antibiotics in the previous 8 weeks, most frequently third-generation cephalosporins (31.7%), and 47.3% had used proton pump inhibitors. Recurrence (9.1%) and mortality (5.2%) rates were low, while complications including colitis or pseudomembranous colitis (13.8%), colectomy (0.4%), and toxic megacolon (0.2%) were uncommon. Common C. difficile strains were ribotypes 017 (16.7%), 014/020 (11.1%) and 018 (9.9%), with wide variation between countries. Binary toxin-positive strains of C. difficile were detected rarely. Overall, disease severity appeared mild, and mortality and recurrence were low. Continued education about, and surveillance of, CDI in Asia are required to reduce the burden of disease.

Performance of laboratory tests for detection for Clostridioides difficile: A multicenter prospective study in Japan

BACKGROUND

The optimal and practical laboratory diagnostic approach for detection of Clostridioides difficile to aid in the diagnosis of C. difficile infection (CDI) is controversial. A two-step algorithm with initial detection of glutamate dehydrogenase (GDH) or nucleic acid amplification test (NAAT) alone are recommended as a predominant method for C. difficile detection in developed countries. The aim of this study was to compare the performance of enzyme immunoassays (EIA) detecting toxins A and B, NAAT detecting the toxin B gene, and GDH compared to toxigenic culture (TC) for C. difficile as the gold standard, in patients prospectively and actively assessed with clinically significant diarrhea in 12 medical facilities in Japan.

METHODS

A total of 650 stool specimens were collected from 566 patients with at least three diarrheal bowel movements (Bristol stool grade 6-7) in the preceding 24 h. EIA and GDH were performed at each hospital, and NAAT and toxigenic C. difficile culture with enriched media were performed at the National Institute of Infectious Diseases. All C. difficile isolates recovered were analyzed by PCR-ribotyping.

RESULTS

Compared to TC, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of EIA were 41%, 96%, 75% and 84%, respectively, and for NAAT were 74%, 98%, 91%, and 92%, respectively. In 439 specimens tested with GDH, the sensitivity, specificity, PPV, and NPV were 73%, 87%, 65%, and 91%, and for an algorithm (GDH plus toxin EIA, arbitrated by NAAT) were 71%, 96%, 85%, and 91%, respectively. Among 157 isolates recovered, 75% of isolates corresponded to one of PCR-ribotypes (RTs) 002, 014, 018/018", and 369; RT027 was not isolated. No clear differences in the sensitivities of any of EIA, NAAT and GDH for four predominant RTs were found.

CONCLUSION

The analytical sensitivities of NAAT and GDH-algorithm to detect toxigenic C. difficile in this study were lower than most previous reports. This study also found low PPV of EIAs. The optimal method to detect C. difficile or its toxins to assist in the diagnosis of CDI needs further investigation.

Molecular epidemiology of Clostridium difficile isolated from piglets

Information on the epidemiology of C. difficile infection (CDI) in South-East Asian countries is limited, as is data on possible animal reservoirs of C. difficile in the region. We investigated the prevalence and molecular epidemiology of C. difficile in piglets and the piggery environment in Thailand and Malaysia. Piglet rectal swabs (n = 224) and piggery environmental specimens (n = 23) were collected between 2015 and 2016 from 11 farms located in Thailand and Malaysia. All specimens were tested for the presence of C. difficile with toxigenic culture. PCR assays were performed on isolates to determine the ribotype (RT), and the presence of toxin genes. Whole genome sequencing was used on a subset of isolates to determine the evolutionary relatedness of RT038 (the most prevalent RT identified) common to pigs and humans from Thailand and Indonesia. C. difficile was recovered from 35% (58/165) and 92% (54/59) of the piglets, and 89% (8/9) and 93% (13/14) of the environmental specimens from Thailand and Malaysia, respectively. All strains from Thailand, and 30 strains from Malaysia (23 piglet and 7 environmental isolates) were non-toxigenic. To our knowledge, this is the first and only report with a complete lack of toxigenic C. difficile among piglets, a feature which could have a protective effect on the host. The most common strain belonged to RT038 (ST48), accounting for 88% (51/58) of piglet and 78% (7/9) of environmental isolates from Thailand, and all 30 isolates tested from Malaysia. Piglet RT038 isolates from Thailand and Malaysia differed by only 18 core-genome single nucleotide variants (cgSNVs) and both were, on average, 30 cgSNVs different from the human strains from Thailand and Indonesia, indicating a common ancestor in the last two decades.

Clostridium difficile ribotype 017 - characterization, evolution and epidemiology of the dominant strain in Asia

Clostridium difficile ribotype (RT) 017 is an important toxigenic C. difficile RT which, due to a deletion in the repetitive region of the tcdA gene, only produces functional toxin B. Strains belonging to this RT were initially dismissed as nonpathogenic and circulated largely undetected for almost two decades until they rose to prominence following a series of outbreaks in the early 2000s. Despite lacking a functional toxin A, C. difficile RT 017 strains have been shown subsequently to be capable of causing disease as severe as that caused by strains producing both toxins A and B. While C. difficile RT 017 strains can be found in almost every continent today, epidemiological studies suggest that the RT is endemic in Asia and that the global spread of this MLST clade 4 lineage member is a relatively recent event. C. difficile RT 017 transmission appears to be mostly from human to human with only a handful of reports of isolations from animals. An important feature of C. difficile RT 017 strains is their resistance to several antimicrobials and this has been documented as a possible factor driving multiple outbreaks in different parts of the world. This review summarizes what is currently known regarding the emergence and evolution of strains belonging to C. difficile RT 017 as well as features that have allowed it to become an RT of global importance.

Analysis of Clinical Isolates of Extended-Spectrum β-Lactamase-Producing Bacteria with Primer and Probe Sets Developed to Detect blaCTX-M, blaTEM, and blaSHV Using a Fully Automated Gene Detection System

In this study, we evaluated extended-spectrum β-lactamase (ESBL)-producing bacteria with the newly developed primer and probe sets to detect bla_CTX-M, bla_TEM, and bla_SHV using BD MAX^TM, a fully automated multiplex polymerase chain reaction assay system. In 36 isolates confirmed by whole-genome sequencing to have bla_CTX-M, bla_TEM, or bla_SHV, the developed primer and probe sets accurately detected each gene without being influenced by the presence of other β-lactamase genes. In nine control strains that do not harbor either bla_CTX-M, bla_TEM, or bla_SHV no cross-reaction was observed. In 191 strains phenotypically determined to be ESBL-producers by conventional antimicrobial susceptibility tests, 189 strains were blaC_TX-M-, bla_TEM-, or bla_SHV-positive as assessed by BD MAX^TM using the developed primer and probe sets, and two strains were negative for these genes. Whole-genome sequencing revealed that these two strains were phenotypically false-positive ESBL-producers. The accuracy of the primer and probe sets seems to be satisfactory, and they may be applicable to detect CTX-M-type ESBL-producing bacteria.

High prevalence and diversity of tcdA-negative and tcdB-positive, and non-toxigenic, Clostridium difficile in Thailand

Studies on the prevalence and diversity of Clostridium difficile in Thailand have been limited to those derived from a few tertiary hospitals in Central Thailand. In this study, 145 C. difficile isolates collected in 13 provinces in Thailand during 2006-2018 were characterized by ribotyping and detection of toxin genes. Minimum inhibitory concentrations of eight antimicrobial agents were determined also for all 100 C. difficile strains collected from 2006 until 2015. Of the 145 strains of C. difficile, 71 (49%) were non-toxigenic, 46 (32%) were toxin A-negative, toxin B-positive (A-B+) and 28 (19%) were A+B+. No binary toxin-positive strain was found. The most common ribotype (RT) was RT 017 (A-B+CDT-, 19%, 28/145). Besides RT 017, 20 novel non-toxigenic and A-B+ ribotyping profiles, which may be related to RT 017 by the similarity of ribotyping profile, were identified. All C. difficile strains remained susceptible to metronidazole and vancomycin, however, a slight increase in MIC for metronidazole was seen in both toxigenic and non-toxigenic strains (overall MIC_50/90 0.25/0.25 mg/L during 2006-2010 compared to overall MIC_50/90 1.0/2.0 mg/L during 2011-2015). There was a high rate of fluoroquinolone resistance among RT 017 strains (77%), but there was little resistance among non-toxigenic strains. These results suggest that RT 017 is endemic in Thailand, and that the misuse of fluoroquinolones may lead to outbreaks of RT 017 infection in this country. Further studies on non-toxigenic C. difficile are needed to understand whether they have a role in the pathogenesis of C. difficile infection in Asia.

Clostridium difficile-associated Diarrhea in Developing Countries: A Systematic Review and Meta-Analysis

Introduction

The prevalence of Clostridium difficile infection is rapidly increasing worldwide, but prevalence is difficult to estimate in developing countries where awareness, diagnostic resources, and surveillance protocols are limited. As diarrhea is the hallmark symptom, we conducted a systematic review and meta-analysis to determine the prevalence and incidence of C. difficile infection in patients in these regions who presented with diarrhea.

Methods

We conducted a systematic literature search of MEDLINE/PubMed, Scopus, and Latin-American and Caribbean Health Sciences Literature databases to identify and analyze data from recent studies providing prevalence or incidence rates of C. difficile-associated diarrhea in developing countries within four regions: Africa–Middle East, developing Asia, Latin America, and China. Our objectives were to determine the current prevalence and incidence density rates of first episodes of C. difficile-associated diarrhea in developing countries.

Results

Within the regions included in our analysis, prevalence of C. difficile infection in patients with diarrhea was 15% (95% CI 13–17%) (including community and hospitalized patients), with no significant difference across regions. The incidence of C. difficile infection in 17 studies including this information was 8.5 per 10,000 patient-days (95% CI 5.83–12.46). Prevalence was significantly higher in hospitalized patients versus community patients (p  = 0.0227).

Conclusion

Our prevalence estimate of 15% is concerning; however, low awareness and inconsistent diagnostic and surveillance protocols suggest this is markedly underestimated. Enhanced awareness and management of C. difficile infection in patients with diarrhea, along with improvements in infection control and surveillance practices, should be implemented to reduce prevalence of C. difficile-associated diarrhea in developing countries.

Funding

Pfizer Inc.

Electronic supplementary material

The online version of this article (10.1007/s40121-019-0231-8) contains supplementary material, which is available to authorized users.

Molecular epidemiology of Clostridium difficile infection in Iranian hospitals

Background

Clostridium difficile infection (CDI) is known as one of the most important causes of nosocomial infections. The main objective of this study was to evaluate the presence of Clostridium difficile in the stool of hospitalized patients with diarrhea as well as in their environments.

Methods

C. difficile isolates were characterized according to the presence of toxin genes and antibiotic resistance. Multilocus Sequence Typing Analysis (MLST) was applied for finding the genetic polymorphism and relationship among strain lineages.

Results

A total of 821 samples (574 stools and 247 swabs) were collected between April 2015 and May 2017. The prevalence of C. difficile isolates was 28.6% (164/574) in patients and 19% (47/247) in swabs taken from medical devices, hands of healthcare workers and skin patient sites. Finally, 11.5% (66/574) toxigenic C. difficile strains isolated from stool samples of inpatients and 4.4% (11/247) from hands of healthcare workers and skin patient sites. All the toxigenic isolates were inhibited by a low concentration of vancomycin (MIC < 0.5 μg/ml). About 43% (33/77) and 39% of isolates were resistant to Clindamycin and moxifloxacin respectively. All isolates were susceptible to metronidazole. Toxigenic C. difficile strains were analyzed by MLST and were divided into 4 different STs. The detected types were ST-54 (57.9%), followed by ST-2 (31.6. %), ST-15 (5.3%) and ST-37 (5.3%), while none of the isolates were identified as ST-1 or ST-11. Significant risk factors for CDI appear to be advanced age, undergoing chemotherapy, previous surgery, and residence in the nursing home.

Conclusions

CDI is common in Iran and further studies are recommended to monitor its epidemiological variations. Moreover, greater attempts must be made to encourage antibiotic stewardship by healthcare workers and the public.

Clostridium difficile in Asia: Opportunities for One Health Management

Clostridium difficile is a ubiquitous spore-forming bacterium which causes toxin-mediated diarrhoea and colitis in people whose gut microflora has been depleted by antimicrobial use, so it is a predominantly healthcare-associated disease. However, there are many One Health implications to C. difficile, given high colonisation rates in food production animals, contamination of outdoor environments by use of contaminated animal manure, increasing incidence of community-associated C. difficile infection (CDI), and demonstration of clonal groups of C. difficile shared between human clinical cases and food animals. In Asia, the epidemiology of CDI is not well understood given poor testing practices in many countries. The growing middle-class populations of Asia are presenting increasing demands for meat, thus production farming, particularly of pigs, chicken and cattle, is rapidly expanding in Asian countries. Few reports on C. difficile colonisation among production animals in Asia exist, but those that do show high prevalence rates, and possible importation of European strains of C. difficile like ribotype 078. This review summarises our current understanding of the One Health aspects of the epidemiology of CDI in Asia.

High Prevalence of Toxigenic and Nontoxigenic Clostridium difficile Strains in Malaysia

Accumulating evidence shows a high prevalence of Clostridium difficile in Southeast Asia associated with a range of clinical presentations. However, severe infections are rarely reported. We investigated C. difficile infection (CDI) across four hospitals in Kuala Lumpur and Kota Bharu, Malaysia. Enzyme immunoassays for glutamate dehydrogenase (GDH) and toxin A or B were performed on diarrheal stool specimens collected from patients in 2015 and 2016. Specimens were also cultured and isolates of C. difficile characterized by PCR ribotyping and detection of toxin genes. In total, 437 specimens were collected and fecal toxin was detected in 3.0%. A further 16.2% of specimens were GDH positive and toxin negative. After culture, toxigenic strains were isolated from 10.3% and nontoxigenic strains from 12.4% of specimens. The most prevalent PCR ribotypes (RTs) were RT 017 (20.0%) and RT 043 (10.0%). The high prevalence of RT 017 and nontoxigenic strains in Malaysia and in neighboring Thailand and Indonesia suggests that they localize to the region of Southeast Asia, with an implication that they may mediate the burden of CDI in the region.

Assessing the Burden of Clostridium difficile Infection in Low- and Middle-Income Countries

In contrast to the significant resources invested in the diagnosis and prevention of Clostridium difficile infection (CDI) in resource-rich settings, in resource-limited settings patients with community- and hospital-acquired diarrhea may not routinely be tested for CDI. Is CDI actually less frequent or severe in resource-limited settings, or might we be missing an important opportunity to prevent CDI-related morbidity and mortality (and to promote antibiotic stewardship) in these settings? Here, we review the literature to assess the overall burden of CDI in low- and middle-income countries.

New Insights into Clostridium difficile (CD) Infection in Latin America: Novel Description of Toxigenic Profiles of Diarrhea-Associated to CD in Bogotá, Colombia

Clostridium difficile (CD) produces antibiotic associated diarrhea and leads to a broad range of diseases. The source of CD infection (CDI) acquisition and toxigenic profile are factors determining the impact of CD. This study aimed at detecting healthcare facility onset- (HCFO) and community-onset (CO) CDI and describing their toxigenic profiles in Bogotá, Colombia. A total of 217 fecal samples from patients suffering diarrhea were simultaneously submitted to two CDI detection strategies: (i) in vitro culture using selective chromogenic medium (SCM; chromID, bioMérieux), followed verification by colony screening (VCS), and (ii) molecular detection targeting constitutive genes, using two conventional PCR tests (conv.PCR) (conv.16S y conv.gdh) and a quantitative test (qPCR.16s). The CD toxigenic profile identified by any molecular test was described using 6 tests independently for describing PaLoc and CdtLoc organization. High overall CDI frequencies were found by both SCM (52.1%) and conv.PCR (45.6% for conv.16S and 42.4% for conv.gdh), compared to reductions of up to half the frequency by VCS (27.2%) or qPCR.16S (22.6%). Infection frequencies were higher for SCM and conv.16S regarding HCFO but greater for CO concerning conv.gdh, such differences being statistically significant. Heterogeneous toxigenic profiles were found, including amplification with lok1/3 primers simultaneously with other PaLoc markers (tcdA, tcdB or tcdC). These findings correspond the first report regarding the differential detection of CDI using in vitro culture and molecular detection tests in Colombia, the circulation of CD having heterogeneous toxigenic profiles and molecular arrays which could affect the impact of CDI epidemiology.

The role of the microbiome and the use of probiotics in gastrointestinal disorders in adults in the Asia-Pacific region - background and recommendations of a regional consensus meeting

The Asia-Pacific region is diverse, with regard to ethnicity, culture, and economic development incorporating some of the world's least and most developed nations. Gastrointestinal diseases are common in the Asia-Pacific region, and their prevalence, presentation, and management vary considerably within the region. There is growing evidence for an important role for the human gut microbiota in gastrointestinal health. As a consequence, geographic variations in the composition of the gut microbiota may contribute to variations in both the prevalence and response to therapy of specific diseases. Probiotics have been proposed as a valuable option in the prevention and treatment of a number of gastrointestinal illnesses, but the quality of available evidence to support their efficacy is variable. A meeting of international experts in adult and pediatric gastroenterology was held at the Sorbonne University, Paris, France, on April 11 and 12, 2016, to discuss current evidence supporting the use of probiotics in gastrointestinal disorders in the Asia-Pacific region. This article provides an overview of the discussions held at this meeting and recommends the formation of an Asia-Pacific Consortium on Gut Microbiota similar to those established in Europe and North America.

Clostridium difficile infection in the Lao People's Democratic Republic: first isolation and review of the literature

Background

Current knowledge of the epidemiology of Clostridium difficile infection in Asia, and in particular the Greater Mekong Subregion, is very limited. Only a few studies from Thailand and Vietnam have been reported from the region with variable testing methods and results, and no studies from Lao People’s Democratic Republic (PDR). Therefore we investigated the presence of C. difficile in a single centre in the Lao PDR and determined the ribotypes present.

Method

Seventy unformed stool samples from hospital inpatients at Mahosot Hospital, Vientiane, were tested for the presence of C. difficile using selective differential agar and confirmed by latex agglutination. C. difficile isolates were further characterised by ribotyping and toxin gene detection.

Results

C. difficile was isolated from five of the 70 patients, and five different ribotypes were identified (014, 017, 020, QX 107 and QX 574).

Conclusion

This is the first isolation of C. difficile from human stool samples in the Lao PDR. These results will add to the limited amount of data on C. difficile in the region. In addition, we hope this information will alert clinicians to the presence of C. difficile in the country and will help inform future investigations into the epidemiology and diagnosis of C. difficile in Lao PDR.

Prevalence of Clostridium difficile infection and colonization in a tertiary hospital and elderly community of North-Eastern Peninsular Malaysia

Little is known about Clostridium difficile infection (CDI) in Asia. The aims of our study were to explore (i) the prevalence, risk factors and molecular epidemiology of CDI and colonization in a tertiary academic hospital in North-Eastern Peninsular Malaysia; (ii) the rate of carriage of C. difficile among the elderly in the region; (iii) the awareness level of this infection among the hospital staffs and students. For stool samples collected from hospital inpatients with diarrhea (n = 76) and healthy community members (n = 138), C. difficile antigen and toxins were tested by enzyme immunoassay. Stool samples were subsequently analyzed by culture and molecular detection of toxin genes, and PCR ribotyping of isolates. To examine awareness among hospital staff and students, participants were asked to complete a self-administered questionnaire. For the hospital and community studies, the prevalence of non-toxigenic C. difficile colonization was 16% and 2%, respectively. The prevalence of CDI among hospital inpatients with diarrhea was 13%. Out of 22 C. difficile strains from hospital inpatients, the toxigenic ribotypes 043 and 017 were most common (both 14%). In univariate analysis, C. difficile colonization in hospital inpatients was significantly associated with greater duration of hospitalization and use of penicillin (both P < 0·05). Absence of these factors was a possible reason for low colonization in the community. Only 3% of 154 respondents answered all questions correctly in the awareness survey. C. difficile colonization is prevalent in a Malaysian hospital setting but not in the elderly community with little or no contact with hospitals. Awareness of CDI is alarmingly poor.

Antimicrobial susceptibility of Clostridium difficile isolated in Thailand

BACKGROUND

Exposure to antimicrobials is the major risk factor associated with Clostridium difficile infection (CDI). Paradoxically, treatment of CDI with antimicrobials remains the preferred option. To date, only three studies have investigated the antimicrobial susceptibility of C. difficile from Thailand, two of which were published in the 1990s. This study aimed to investigate the contemporary antibiotic susceptibility of C. difficile isolated from patients in Thailand.

METHODS

A collection of 105 C. difficile isolated from inpatients admitted at Siriraj Hospital in Bangkok in 2015 was tested for their susceptibility to nine antimicrobials via an agar incorporation method.

RESULTS

All isolates were susceptible to vancomycin, metronidazole, amoxicillin/clavulanate and meropenem. Resistance to clindamycin, erythromycin and moxifloxacin was observed in 73.3%, 35.2% and 21.0% of the isolates, respectively. The in vitro activity of fidaxomicin (MIC50/MIC90 0.06/0.25 mg/L) was superior to first-line therapies vancomycin (MIC50/MIC90 1/2 mg/L) and metronidazole (MIC50/MIC90 0.25/0.25 mg/L). Rifaximin exhibited potent activity against 85.7% of the isolates (MIC ≤0.03 mg/L), and its MIC50 (0.015 mg/L) was the lowest among all antimicrobials tested. The prevalence of multi-drug resistant C. difficile, defined by resistance to ≥3 antimicrobials, was 21.9% (23/105).

CONCLUSIONS

A high level of resistance against multiple classes of antimicrobial was observed, emphasising the need for enhanced antimicrobial stewardship and educational programmes to effectively disseminate information regarding C. difficile awareness and appropriate use of antimicrobials to healthcare workers and the general public.

Prevalence and molecular epidemiology of Clostridium difficile infection in Indonesia

Clostridium difficile has not been studied in detail in Asia, particularly Southeast Asia. We thus performed a prevalence study across four hospitals in Central Java province, Indonesia. Stool samples were collected from patients with diarrhoea and tested by enzyme immunoassay for glutamate dehydrogenase (GDH) and toxin A/B (C DIFF QUIK CHEK COMPLETE, TechLab). Specimens were cultured and molecular typing was performed. In total, 340 samples were tested, of which 70 (20.6%) were GDH positive, with toxin detected in 19 (5.6%). Toxigenic C. difficile was isolated from 37 specimens (10.9%), while a further 36 (10.6%) nontoxigenic isolates were identified. The most common strain was ribotype 017 (24.3% of 74 isolates), followed by nontoxigenic types QX 224 (9.5%), and QX 238 and QX 108 (both 8.1%). The high prevalence of C. difficile highlights a need for ongoing surveillance of C. difficile infection in Indonesia.