Laboratory-Based Surveillance of Clostridium difficile Infection in Australian Health Care and Community Settings, 2013 to 2018

Biogeographic distribution and molecular epidemiology of Clostridioides (Clostridium) difficile in Western Australian soils

Clostridioides (Clostridium) difficile is a leading cause of infectious diarrhea in humans and production animals and can be found in a variety of environmental sources. The prevalence and diversity of multi-locus sequence type clade 5 strains of C. difficile in Australian production animals suggest Australia might be the ancestral home of this lineage of One Health importance. To better understand the role of the environment in the colonization of humans and animals in Australia, it is important to investigate these endemic sources. This study describes the prevalence, molecular epidemiology, and biogeographic distribution of C. difficile in soils of Western Australia. A total of 321 soil samples from remote geographical locations across the eight health regions of Western Australia were screened for C. difficile and isolates characterized by PCR ribotyping and toxin gene profiling. C. difficile was isolated from 31.15% of samples, with the highest prevalence in the Perth Metropolitan Health Region (49.25%, n = 33/67). Overall, 52 different strains [PCR ribotypes (RTs)] were identified, with 14 being novel, and 38% (38/100) of isolates being toxigenic, the most common of which was RT014/020. Five unique novel isolates showed characteristics similar to C. difficile clade 5. This is the first study of C. difficile isolated from soils in Australia. The high prevalence and heterogeneity of C. difficile strains recovered suggest that soils play a role in the survival and environmental dissemination of this organism, and potentially its transmission among native wildlife and production animals, and in community and hospital settings.IMPORTANCEClostridium difficile is a pathogen of One Health importance. To better understand the role of the environment in human and animal colonization/infection, it is critical that autochthonous reservoirs/sources of C. difficile be investigated. This is the first study of C. difficile isolated from soils of Western Australia (WA). Here, the ecology of C. difficile in WA is described by examining the geographic distribution, molecular epidemiology, and diversity of C. difficile isolated from soils across WA.

Genomic Analysis of Clostridioides difficile Recovered from Horses in Western Australia

Clostridioides difficile poses an ongoing threat as a cause of gastrointestinal disease in humans and animals. Traditionally considered a human healthcare-related disease, increases in community-associated C. difficile infection (CDI) and growing evidence of inter-species transmission suggest a wider perspective is required for CDI control. In horses, C. difficile is a major cause of diarrhoea and life-threatening colitis. This study aimed to better understand the epidemiology of CDI in Australian horses and provide insights into the relationships between horse, human and environmental strains. A total of 752 faecal samples from 387 Western Australian horses were collected. C. difficile was isolated from 104 (30.9%) horses without gastrointestinal signs and 19 (37.8%) with gastrointestinal signs. Of these, 68 (55.3%) harboured one or more toxigenic strains, including C. difficile PCR ribotypes (RTs) 012 (n = 14), 014/020 (n = 10) and 087 (n = 7), all prominent in human infection. Whole-genome analysis of 45 strains identified a phylogenetic cluster of 10 closely related C. difficile RT 012 strains of equine, human and environmental origin (0-62 SNP differences; average 23), indicating recent shared ancestry. Evidence of possible clonal inter-species transmission or common-source exposure was identified for a subgroup of three horse and one human isolates, highlighting the need for a One Health approach to C. difficile surveillance.

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.

Effects of Omeprazole on Recurrent Clostridioides difficile Infection Caused by ST81 Strains and Their Potential Mechanisms

Clostridioides difficile infection (CDI) is associated with high recurrence rates that have substantial effects on patients' quality of life. To investigate the risk factors and potential mechanisms contributing to recurrent CDI (rCDI), a total of 243 cases were enrolled in this study. The history of omeprazole (OME) medication and ST81 strain infection were considered the two independent risks with the highest odds ratios in rCDI. In the presence of OME, we detected concentration-dependent increases in the MIC values of fluoroquinolone antibiotics against ST81 strains. Mechanically, OME facilitated ST81 strain sporulation and spore germination by blocking the pathway of purine metabolism and also promoted an increase in cell motility and toxin production by turning the flagellar switch to the ON state. In conclusion, OME affects several biological processes during C difficile growth, which have fundamental impacts on the development of rCDI caused by ST81 strains. Programmed OME administration and stringent surveillance of the emerging ST81 genotype are matters of considerable urgency and significance in rCDI prevention.

Clostridioides difficile Infection: Clinical Practice and Health Outcomes in 6 Large Tertiary Hospitals in Eastern Australia

Background

Clostridioides difficile infection (CDI) is associated with significant morbidity and mortality in both healthcare and community settings. We aimed to define the predisposing factors, risks for severe disease, and mortality determinants of CDI in eastern Australia over a 1-year period.

Methods

This is an observational retrospective study of CDI in hospitalized patients aged ≥18 years in 6 tertiary institutions from 1 January 2016 to 31 December 2016. Patients were identified through laboratory databases and medical records of participating institutions. Clinical, imaging, and laboratory data were input into an electronic database hosted at a central site.

Results

A total of 578 patients (578 CDI episodes) were included. Median age was 65 (range, 18-99) years and 48.2% were male. Hospital-onset CDI occurred in 64.0%. Recent antimicrobial use (41.9%) and proton pump inhibitor use (35.8%) were common. Significant risk factors for severe CDI were age <65 years (P < .001), malignancy within the last 5 years (P < .001), and surgery within the previous 30 days (P < .001). Significant risk factors for first recurrence included severe CDI (P = .03) and inflammatory bowel disease (P = .04). Metronidazole was the most common regimen for first episodes of CDI with 65.2% being concordant with Australian treatment guidelines overall. Determinants for death at 60 days included age ≥65 years (P = .01), severe CDI (P < .001), and antibiotic use within the prior 30 days (P = .02). Of those who received metronidazole as first-line therapy, 10.1% died in the 60-day follow-up period, compared to 9.8% of those who received vancomycin (P = .86).

Conclusions

Patients who experience CDI are vulnerable and require early diagnosis, clinical surveillance, and effective therapy to prevent complications and improve outcomes.

Genomic epidemiology and transmission dynamics of recurrent Clostridioides difficile infection in Western Australia

Recurrent cases of Clostridioides difficile infection (rCDI) remain one of the most common and serious challenges faced in the management of CDI. The accurate distinction between a relapse (caused by infection with the same strain) and reinfection (caused by a new strain) has implications for infection control and prevention, and patient therapy. Here, we used whole-genome sequencing to investigate the epidemiology of 94 C. difficile isolates from 38 patients with rCDI in Western Australia. The C. difficile strain population comprised 13 sequence types (STs) led by ST2 (PCR ribotype (RT) 014, 36.2%), ST8 (RT002, 19.1%) and ST34 (RT056, 11.7%). Among 38 patients, core genome SNP (cgSNP) typing found 27 strains (71%) from initial and recurring cases differed by ≤ 2 cgSNPs, suggesting a likely relapse of infection with the initial strain, while eight strains differed by ≥ 3 cgSNPs, suggesting reinfection. Almost half of patients with CDI relapse confirmed by WGS suffered episodes that occurred outside the widely used 8-week cut-off for defining rCDI. Several putative strain transmission events between epidemiologically unrelated patients were identified. Isolates of STs 2 and 34 from rCDI cases and environmental sources shared a recent evolutionary history, suggesting a possible common community reservoir. For some rCDI episodes caused by STs 2 and 231, within-host strain diversity was observed, characterised by loss/gain of moxifloxacin resistance. Genomics improves discrimination of relapse from reinfection and identifies putative strain transmission events among patients with rCDI. Current definitions of relapse and reinfection based on the timing of recurrence need to be reconsidered.

Spore-Forming Clostridium (Clostridioides) difficile in Wastewater Treatment Plants in Western Australia

There is growing evidence that shows Clostridium (Clostridioides) difficile is a pathogen of One Health importance with a complex dissemination pathway involving animals, humans, and the environment. Thus, environmental discharge and agricultural recycling of human and animal waste have been suspected as factors behind the dissemination of Clostridium difficile in the community. Here, the presence of C. difficile in 12 wastewater treatment plants (WWTPs) in Western Australia was investigated. Overall, C. difficile was found in 90.5% (114/126) of raw sewage influent, 48.1% (50/104) of treated effluent, 40% (2/5) of reclaimed irrigation water, 100% (38/38) of untreated biosolids, 95.2% (20/21) of anaerobically digested biosolids, and 72.7% (8/11) of lime-amended biosolids. Over half of the isolates (55.3% [157/284]) were toxigenic, and 97 C. difficile ribotypes (RTs) were identified, with RT014/020 the most common (14.8% [42/284]). Thirteen C. difficile isolates with the toxin gene profile A⁺ B⁺ CDT⁺ (positive for genes coding for toxins A and B and the binary C. difficile transferase toxin [CDT]) were found, including the hypervirulent RT078 strain. Resistance to the antimicrobials fidaxomicin, vancomycin, metronidazole, rifaximin, amoxicillin-clavulanate, meropenem, and moxifloxacin was uncommon; however, resistance to clindamycin, erythromycin, and tetracycline was relatively frequent at 56.7% (161/284), 14.4% (41/284), and 13.7% (39/284), respectively. This study revealed that toxigenic C. difficile was commonly encountered in WWTPs and being released into the environment. This raises concern about the possible spillover of C. difficile into animal and/or human populations via land receiving the treated waste. In Western Australia, stringent measures are in place to mitigate the health and environmental risk of recycling human waste; however, further studies are needed to elucidate the public health significance of C. difficile surviving the treatment processes at WWTPs. IMPORTANCE Clostridium difficile infection (CDI) is a leading cause of antimicrobial-associated diarrhea in health care facilities. Extended hospital stays and recurrences increase the cost of treatment and morbidity and mortality. Community-associated CDI (CA-CDI) cases, with no history of antimicrobial use or exposure to health care settings, are increasing. The isolation of clinically important C. difficile strains from animals, rivers, soil, meat, vegetables, compost, treated wastewater, and biosolids has been reported. The objective of this study was to characterize C. difficile in wastewater treatment plants (WWTPs) in Australia. We found that C. difficile can survive the treatment processes of WWTPs, and toxigenic C. difficile was being released into the environment, becoming a potential source/reservoir for CA-CDI.

COVID-19 rapid molecular point-of-care testing is effective and cost-beneficial for the acute care of trauma patients

PURPOSE

To evaluate the accuracy and cost benefit of a rapid molecular point-of-care testing (POCT) device detecting COVID-19 within a traumatological emergency department.

BACKGROUND

Despite continuous withdrawal of COVID-19 restrictions, hospitals will remain particularly vulnerable to local outbreaks which is reflected by a higher institution-specific basic reproduction rate. Patients admitted to the emergency department with unknown COVID-19 infection status due to a- or oligosymptomatic COVID-19 infection put other patients and health care workers at risk, while fast diagnosis and treatment is necessary. Delayed testing results in additional costs to the health care system.

METHODS

From the 8th of April 2021 until 31st of December 2021, all patients admitted to the emergency department were tested with routine RT-PCR and rapid molecular POCT device (Abbott ID NOW™ COVID-19). COVID-19-related additional costs for patients admitted via shock room or emergency department were calculated based on internal cost allocations.

RESULTS

1133 rapid molecular tests resulted in a sensitivity of 83.3% (95% CI 35.9-99.6%), specificity of 99.8% (95% CI 99.4-100%), a positive predictive value of 71.4% (95% CI 29-96.3%) and a negative predictive value of 99.9% (95% CI 99.5-100%) as compared to RT-PCR. Without rapid COVID-19 testing, each emergency department and shock room admission with subsequent surgery showed additional direct costs of 2631.25€, without surgery of 729.01€.

CONCLUSION

Although rapid molecular COVID-19 testing can initially be more expensive than RT-PCR, subsequent cost savings, improved workflows and workforce protection outweigh this effect by far. The data of this study support the use of a rapid molecular POCT device in a traumatological emergency department.

Sentinel surveillance and epidemiology of Clostridioides difficile in Denmark, 2016 to 2019

BackgroundSince 2008, Danish national surveillance of Clostridioides difficile has focused on binary toxin-positive strains in order to monitor epidemic types such as PCR ribotype (RT) 027 and 078. Additional surveillance is needed to provide a more unbiased representation of all strains from the clinical reservoir.AimSetting up a new sentinel surveillance scheme for an improved understanding of type distribution relative to time, geography and epidemiology, here presenting data from 2016 to 2019.MethodsFor 2─4 weeks in spring and autumn each year between 2016 and 2019, all 10 Danish Departments of Clinical Microbiology collected faecal samples containing toxigenic C. difficile. Isolates were typed at the national reference laboratory at Statens Serum Institut. The typing method in 2016-17 used tandem-repeat-sequence typing, while the typing method in 2018-19 was whole genome sequencing.ResultsDuring the study period, the sentinel surveillance scheme included ca 14-15% of all Danish cases of C. difficile infections. Binary toxin-negative strains accounted for 75% and 16 of the 20 most prevalent types. The most common sequence types (ST) were ST2/13 (RT014/020) (19.5%), ST1 (RT027) (10.8%), ST11 (RT078) (6.7%), ST8 (RT002) (6.6%) and ST6 (RT005/117) (5.1%). The data also highlighted geographical differences, mostly related to ST1 and temporal decline of ST1 (p = 0.0008) and the increase of ST103 (p = 0.002), ST17 (p = 0.004) and ST37 (p = 0.003), the latter three binary toxin-negative.ConclusionSentinel surveillance allowed nationwide monitoring of geographical differences and temporal changes in C. difficile infections in Denmark, including emerging types, regardless of binary toxin status.

Make It Less difficile: Understanding Genetic Evolution and Global Spread of Clostridioides difficile

Clostridioides difficile is an obligate anaerobic pathogen among the most common causes of healthcare-associated infections. It poses a global threat due to the clinical outcomes of infection and resistance to antibiotics recommended by international guidelines for its eradication. In particular, C. difficile infection can lead to fulminant colitis associated with shock, hypotension, megacolon, and, in severe cases, death. It is therefore of the utmost urgency to fully characterize this pathogen and better understand its spread, in order to reduce infection rates and improve therapy success. This review aims to provide a state-of-the-art overview of the genetic variation of C. difficile, with particular regard to pathogenic genes and the correlation with clinical issues of its infection. We also summarize the current typing techniques and, based on them, the global distribution of the most common ribotypes. Finally, we discuss genomic surveillance actions and new genetic engineering strategies as future perspectives to make it less difficile.

Clostridioides (Clostridium) difficile isolated from paediatric patients in Western Australia 2019-2020

Less is understood about the epidemiology of Clostridioides difficile infection (CDI) in children compared to adults, and its impact is complicated by variations in the natural development of infection in paediatric patients. The interplay of rising CDI incidence in hospitalised paediatric patients, emergence of hypervirulent strains and community associated CDI (CA-CDI) in the past decade is a potential threat in both hospital and community settings. Research in Australia regarding paediatric CDI is limited. Here, we report the molecular characterisation of C. difficile isolated from paediatric patients at a tertiary hospital in Perth, Western Australia. A total of 427 stool samples was collected from patients aged from <1 to 17 years being investigated for diarrhoea from July 2019 to June 2020. Stool specimens were cultured and isolates of C. difficile characterised by ribotyping and toxin gene profiling. Clostridioides difficile was recovered from 84/427 (19.7%) samples tested. The most prevalent PCR ribotypes (RTs) were RT 002 (12.4%), a toxigenic strain, and RT 009 (15.7%), a non-toxigenic strain. Interestingly, C. difficile RT 078 and RT 017, strains that are not endemic in Australia, were isolated from a 1- and 4-year-old child, respectively. Clostridioides difficile RT 106, a strain of emerging importance in Australia, was recovered from two cases (5.3%). Resistance to metronidazole, fidaxomicin, amoxicillin, rifaximin and meropenem was not detected, however, 45 isolates (50.6%) showed resistance to at least one agent, and multidrug resistance was observed in 13.3% of the resistant isolates (6/45). This study provides a baseline for future surveillance of paediatric CDI in Australia. Given that young children can be asymptomatically colonised with toxigenic C. difficile strains, they represent a potential reservoir of strains causing CDI in adults.

Whole-genome sequencing links Clostridium (Clostridioides) difficile in a single hospital to diverse environmental sources in the community

AIMS

To investigate if Clostridium (Clostridioides) difficile infection (CDI), traditionally thought of as hospital-acquired, can be genomically linked to hospital or community environmental sources, and to define possible importation routes from the community to the hospital.

METHODS AND RESULTS

In 2019, C. difficile was isolated from 89/300 (29.7%) floor and 96/300 (32.0%) shoe sole samples at a tertiary hospital in Western Australia. Non-toxigenic C. difficile ribotype (RT) 010 predominated among floor (96.6%) and shoe sole (73.2%) isolates, while toxigenic RT 014/020 was most prevalent among contemporaneous clinical cases (33.0%) at the hospital. Whole-genome sequencing and high-resolution core genome single nucleotide polymorphism (cgSNP) analysis on C. difficile strains from hospital and community sources showed no clinical C. difficile RT 014/020 strains were genetically related, and evidence of frequent long-distance, multi-directional spread between humans, animals and the environment. In addition, cgSNP analysis of environmental RT 010 strains suggested transportation of C. difficile via shoe soles.

CONCLUSIONS

While C. difficile RT 014/020 appears to spread via routes outside the healthcare system, RT 010 displayed a pattern of possible importation from the community into the hospital.

SIGNIFICANCE AND IMPACT OF STUDY

These findings suggest developing community-based infection prevention and control strategies could significantly lower rates of CDI in the hospital setting.

Molecular Epidemiology of Clostridioides difficile Infections in Children

Clostridioides difficile is a prominent cause of health care-related gastrointestinal illness in adults. C. difficile infection (CDI) has been researched for over 40 years; however, research on pediatric CDI specifically has lagged behind for various reasons. Over the past decade, C. difficile has been increasingly reported as a cause of a broad spectrum of gastrointestinal diseases in children, ranging from mild self-limiting diarrhea to severe conditions such as pseudomembranous colitis and toxic megacolon. Recent publications have shown a rise in CDI incidence in children in different parts of the world, especially in patients with particular comorbidities such as hematological malignancies and inflammatory bowel disease. In addition, rising CDI rates have been reported in children in the community without traditional risk factors for CDI. Due to the extensive use of sensitive molecular detection methods to diagnose CDI in many countries, differentiating children who require treatment from those colonized with toxigenic strains remains a problem. Consequently, the molecular epidemiology of pediatric CDI is poorly understood. Even though well-known C. difficile strains causing CDI in children have been described (including hypervirulent strains such as ribotypes 027 and 078), there is a paucity of information about specific C. difficile strains. This mini-review summarizes the information that is currently available on the molecular epidemiology of CDI in children.

Prevalence and outcomes of Clostridioides difficile infection in liver transplant recipients

BACKGROUND AND AIM

Data are limited on whether Clostridioides difficile infection (CDI) in the first year after liver transplantation (LT) is associated with increased mortality. In an Australian setting without hypervirulent strain of C. difficile we investigated the prevalence, risk factors, and patient survival associated with CDI in LT.

METHODS

Consecutive patients who underwent deceased-donor LT from 2007 to 2017 were studied retrospectively. Prevalence and long-term outcomes of LT recipients with and without CDI were examined in the entire LT cohort. A case-control study was performed to investigate risk factors associated with CDI.

RESULTS

Six hundred and forty-nine patients underwent LT, of which 32 (4.9%) were diagnosed with CDI within the first 12 months post-LT. There was no difference in patient survival in the overall LT cohort on Kaplan-Meier analysis when stratified by CDI status (log-rank test, p = .08). Furthermore, age was the only predictor of mortality on Cox regression (hazard ratio (HR) 1.06, 95% confidence interval (CI) 1.00-1.13, p = .03). On multivariable logistic regression, rifaximin pre-LT reduced risk (odds ratio (OR) 0.22, 95% CI 0.65-0.74, p = .01) whereas antibiotics pre-LT (OR 7.02, 95% CI 1.26-39.01, p = .03) and length of hospital stay after LT (OR 1.03, 95% CI 1.01-1.06, p = .02) were associated with increased risk of CDI.

CONCLUSIONS

Within the local setting of our study, CDI within 12 months post-LT is of low severity, associated with pre-LT antibiotic exposure and longer hospital stay but no survival impact after LT. Rifaximin use pre-LT reduced the risk of CDI post-LT.

Genetically related Clostridium difficile from water sources and human CDI cases revealed by whole-genome sequencing

Clostridium difficile isolates from the environment are closely related to those from humans, indicating a possible environmental transmission route for C. difficile infection (CDI). In this study, C. difficile was isolated from 47.3% (53/112) of lake/pond, 23.0% (14/61) of river, 20.0% (3/15) of estuary and 0.0% (0/89) of seawater samples. The most common toxigenic strain isolated was C. difficile PCR ribotype (RT) 014/020 (10.5%, 8/76). All water isolates were susceptible to fidaxomicin, metronidazole, rifaximin, amoxicillin/clavulanic acid, moxifloxacin and tetracycline. Resistance to vancomycin, clindamycin, erythromycin and meropenem was detected in 5.3% (4/76), 26.3% (20/76), 1.3% (1/76) and 6.6% (5/76) of isolates, respectively. High-resolution core-genome analysis was performed on RT 014/020 isolates of water origin and 26 clinical RT 014/020 isolates from the same year and geographical location. Notably, both human and water strains were intermixed across three sequence types (STs), 2, 13 and 49. Six closely related groups with ≤10 core-genome single nucleotide polymorphisms were identified, five of which comprised human and water strains. Overall, 19.2% (5/26) of human strains shared a recent genomic relationship with one or more water strains. This study supports the growing hypothesis that environmental contamination by C. difficile plays a role in CDI transmission.

Complete Genome Assemblies of Three Highly Prevalent, Toxigenic Clostridioides difficile Strains Causing Health Care-Associated Infections in Australia

Clostridioides difficile infection (CDI) is the leading cause of life-threatening health care-related gastrointestinal illness worldwide. Phylogenetically appropriate closed reference genomes are essential for studies of C. difficile transmission and evolution. Here, we provide high-quality complete hybrid genome assemblies for the three most prevalent C. difficile strains causing CDI in Australia.

Antimicrobial resistance surveillance of Clostridioides difficile in Australia, 2015-18

BACKGROUND

Clostridioides difficile was listed as an urgent antimicrobial resistance (AMR) threat in a report by the CDC in 2019. AMR drives the evolution of C. difficile and facilitates its emergence and spread. The C. difficile Antimicrobial Resistance Surveillance (CDARS) study is nationwide longitudinal surveillance of C. difficile infection (CDI) in Australia.

OBJECTIVES

To determine the antimicrobial susceptibility of C. difficile isolated in Australia between 2015 and 2018.

METHODS

A total of 1091 strains of C. difficile were collected over a 3 year period by a network of 10 diagnostic microbiology laboratories in five Australian states. These strains were tested for their susceptibility to nine antimicrobials using the CLSI agar incorporation method.

RESULTS

All strains were susceptible to metronidazole, fidaxomicin, rifaximin and amoxicillin/clavulanate and low numbers of resistant strains were observed for meropenem (0.1%; 1/1091), moxifloxacin (3.5%; 38/1091) and vancomycin (5.7%; 62/1091). Resistance to clindamycin was common (85.2%; 929/1091), followed by resistance to ceftriaxone (18.8%; 205/1091). The in vitro activity of fidaxomicin [geometric mean MIC (GM) = 0.101 mg/L] was superior to that of vancomycin (1.700 mg/L) and metronidazole (0.229 mg/L). The prevalence of MDR C. difficile, as defined by resistance to ≥3 antimicrobial classes, was low (1.7%; 19/1091).

CONCLUSIONS

The majority of C. difficile isolated in Australia did not show reduced susceptibility to antimicrobials recommended for treatment of CDI (vancomycin, metronidazole and fidaxomicin). Resistance to carbapenems and fluoroquinolones was low and MDR was uncommon; however, clindamycin resistance was frequent. One fluoroquinolone-resistant ribotype 027 strain was detected.