Serotypes, Antimicrobial Susceptibility, andgyr AGene Mutation ofCampylobacter jejuniIsolates from Humans and Chickens in Thailand

The characterization and correlation between the phenotypic and genotypic resistance of Campylobacter spp. isolates from commercial broilers and native chickens in the south of Thailand

RESEARCH HIGHLIGHTS

High Campylobacter prevalence in chickens; C. jejuni more prevalent than C. coli.Susceptibility to macrolides but resistance to quinolones/tetracyclines in isolates.Homogeneous resistance patterns within farms; higher in broilers than in native birds.Partial association between phenotypic and genotypic resistance among isolates.

A systematic review and meta-analysis of Penner serotype prevalence of Campylobacter jejuni in low- and middle-income countries

Introduction

While Campylobacter jejuni is a leading foodborne bacterial pathogen worldwide, it poses a particular risk to susceptible populations in low- and middle-income countries (LMICs). A capsule-conjugate vaccine approach has been proposed as a potential solution, but little information exists on circulating C. jejuni capsule types in LMICs. The capsule is the major serodeterminant of the Penner typing scheme, which is based on serum recognition of Campylobacter heat-stable antigens. We conducted a systematic review and meta-analysis to estimate the distribution of Penner serotypes associated with C. jejuni enteritis in LMICs. Vaccine coverage assessments for hypothetical regional and global C. jejuni vaccines were also estimated.

Methods

A systematic review of the literature published from 1980 to 2019 was performed using PubMed, Scopus, and Web of Science databases. Articles were assessed for eligibility and data were abstracted. Pooled C. jejuni serotype prevalence in LMICs was estimated by region and globally using random-effects models.

Results

A total of 36 studies were included, capturing 4,434 isolates from LMICs. Fifteen serotypes were present in a sufficient number of studies to be included in analyses. Among these, HS4c was the most common serotype globally (12.6%), though leading capsule types varied among regions. HS2, HS3c, HS4c, HS5/31, HS8/17, and HS10 were all among the 10 most common region-specific serotypes.

Conclusions

The results of this review suggest that an octavalent vaccine could provide up to 66.9% coverage of typable strains worldwide, and 56.8–69.0% regionally. This review also highlights the paucity of available data on capsules in LMICs; more testing is needed to inform vaccine development efforts.

Prevalence and antimicrobial susceptibility of Campylobacter isolated from retail chickens in Thailand

Campylobacter is an important foodborne pathogen causing bacterial gastroenteritis worldwide; however, there has been a lack of information over the past decade on its occurrence, antibiotic susceptibility and genetic diversity in Thailand. Poultry meat is considered as a reservoir for transmission of Campylobacter to humans. This study determines the prevalence and antimicrobial resistance patterns of Campylobacter spp. on chicken samples purchased from 50 local wet markets and supermarkets in central Thailand. Of the 296 samples, 99 (33.5%) were contaminated with C. jejuni, 54 (18.2%) were C. coli and 15 (5.1%) were contaminated with both species. Antibiotic resistance rate is higher among C. coli isolates; 100%, 76.8%, 37.7%, 36.2% and 13.0% were resistant to quinolones, cyclines, macrolides, clindamycin and gentamicin, respectively. Most of the C. jejuni isolates were resistant to quinolones (79.8%) and cyclines (38.6%) whereas resistance to macrolides, clindamycin and gentamicin was found to be 1.8%. Multi-drug resistance (i.e. to three or more unrelated antimicrobials) was detected in 37.7% of C. coli and 1.8% of C. jejuni isolates. This study has revealed high contamination rates and alarming levels of antimicrobial resistance in Campylobacter spp. isolated from retail chicken samples in Thailand, suggesting the necessity of implementing interventions to reduce its prevalence from farm to table in the country.

High Prevalence of Resistance to Fluoroquinolones and Tetracycline Campylobacter Spp. Isolated from Poultry in Poland

Campylobacter spp. is a major cause of foodborne diseases in humans, particularly when transmitted by the handling or consumption of undercooked poultry meat. Most Campylobacter infections are self-limiting, but antimicrobial treatment (e.g., fluoroquinolones and macrolides) is necessary in severe or prolonged cases. The indiscriminate use of these drugs, both in clinical medicine and animal production, has a major impact on public health. The aim of the present study was to identify Campylobacter strains, isolated from turkey and broilers, using both PCR and the matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) methods to reveal the accuracy of identification, as well to evaluate the antimicrobial and genetic resistance of the investigated strains. MALDI-TOF and PCR methods were used to show differences, if any, in the specificity of that test. In this study, MALDI-TOF mass spectrometry gave the same results as multiplex PCR, in all cases. The highest rate of resistance (i.e., 100% of turkey and broiler strains) was detected against ciprofloxacin, whereas 58.1% of turkey and 78.6% of broiler strains were resistant to tetracycline. Multidrug-resistant isolates were not found in the study. All ciprofloxacin-resistant strains had a mutation in the gyrA gene, at the Thr-86 position. The presence of the tetO gene was found in 71% of turkey and in 100% of broiler strains. All resistant to tetracycline strains included tetO gene. Additionally, in five turkey and three broiler strains, susceptible to tetracycline, tetO gene was present. These results indicate the high prevalence of Campylobacter strains, which are phenotypically and genetically resistant to fluoroquinolones and tetracycline.

Prevalence of Genetic Determinants and Phenotypic Resistance to Ciprofloxacin in Campylobacter jejuni from Lithuania

Recently, the number of reports on isolation of ciprofloxacin resistant Campylobacter jejuni has increased worldwide. The aim of this study was to determine the prevalence of resistance to ciprofloxacin and its genetic determinants among C. jejuni isolated from humans (n = 100), poultry products (n = 96) and wild birds (n = 96) in Lithuania. 91.4% of the C. jejuni isolates were phenotypically resistant to ciprofloxacin. DNA sequence analyses of the gyrA gene from 292 isolates revealed that a change in amino acid sequence, Thr86Ile, was the main substition conferring resistance to ciprofloxacin. This change was significantly associated with isolates from poultry products (P < 0.05) and humans (P < 0.05). A total of 26.7% of C. jejuni isolates from human (n = 47), poultry products (n = 30) and wild bird (n = 1), had a mutation from Ser at position 22, and six had an additional mutation from Ala at position 39. Eight isolates from poultry and two isolates from human, corresponding to 67.0% of isolates with MICs ≥128 μg/ml, showed missense mutations Thr86Ile (ACA → ATA) and Ser22Gly (AGT → GGT) together, whereas isolates without these mutations showed lower MIC values (from 4 to 64 μg/ml). Two hundred forty-five C. jejuni isolates showed one or more silent mutations, and 32.4% of examined isolates possessed six silent mutations. In addition to the ciprofloxacin resistant isolates harboring only Thr86Ile point mutation (110 isolates), the current study identified resistant isolates (n = 101) harboring additional point mutations (Ser22Gly, Ala39Ser, Arg48Lys, Thr85Ala Ala122Ser, Glu136Asp, Vall49Ile), and strains (n = 57) having only Glu136Asp point mutation. The study highlight the potential public health problem with elevated ciprofloxacin resistance in Campylobacters from poultry meat, wild birds and humans, and the need for extensive surveillance enabling to follow changes of antimicrobial resistance development in this species.

Antimicrobial resistance and antimicrobial use associated with laboratory-confirmed cases of Campylobacter infection in two health units in Ontario

AIM

A population-based study was conducted over a two-year period in the Perth District (PD) and Wellington-Dufferin-Guelph (WDG) health units in Ontario to document antimicrobial resistance and antimicrobial use associated with clinical cases of laboratory-confirmed campylobacteriosis.

METHODS

Etest (bioMérieux SA, France) was used to determine the minimum inhibitory concentration of amoxicillin/clavulanic acid, ampicillin, chloramphenicol, ciprofloxacin (CIP), clindamycin, erythromycin (ERY), gentamicin, nalidixic acid and tetracycline. Data regarding antimicrobial use were collected from 250 cases.

RESULTS

Of the 250 cases, 165 (65.7%) reported staying home or being hospitalized due to campylobacteriosis. Fifty-four per cent of cases (135 of 249) reported taking antimicrobials to treat campylobacteriosis. In 115 cases (51.1%), fecal culture results were not used for treatment decisions because they were not available before the initiation of antimicrobial treatment and/or they were not available before the cessation of symptoms. Of the 250 cases, 124 (49.6%) had available Campylobacter isolates, of which 66 (53.2%) were resistant to at least one of the antimicrobials tested. No resistance to ampicillin, chloramphenicol or gentamicin was found in these isolates. Six isolates (4.8%) were resistant to CIP. Two isolates (1.6%) were resistant to ERY; however, no isolates were resistant to both CIP and ERY.

CONCLUSION

Prudent use practices should be promoted among physicians to reduce the use of antimicrobials for the treatment of gastroenteritis in general and campylobacteriosis in particular, as well as to minimize the future development of resistance to these antimicrobials in Campylobacter species.

Prevalence, quantitative load, and antimicrobial resistance of Campylobacter spp. from broiler ceca and broiler skin samples in Thailand

This study was conducted to determine the prevalence of Campylobacter spp. in broiler flocks by testing cecal contents at slaughter and to detect and quantify Campylobacter on broiler carcass skin samples of the corresponding slaughter batches, to determine antimicrobial resistance patterns of the Campylobacter isolates, and to genotype selected Campylobacter jejuni isolates using multilocus sequence typing analysis. Ninety-eight broiler flocks were included in the study. Intact ceca were randomly taken at the time of evisceration throughout a slaughter batch to detect Campylobacter spp. at the broiler flock level and one whole carcass per slaughter batch was taken for the detection of Campylobacter spp. on broiler skin. The prevalences of Campylobacter spp. in broiler ceca and broiler skin samples were 11.2% (11/98) and 51% (50/98), respectively. Even though most Campylobacter-positive broiler skin samples were contaminated with only up to 230 most probable number per gram, a substantial share (13.3%) showed very high Campylobacter numbers on the broiler skin samples (most probable number = ∞; lower confidence limit T(0) 580/g). From 32 C. jejuni and Campylobacter coli isolates tested, the highest antimicrobial resistance rates were found for ciprofloxacin (81.2%), followed by tetracycline (40.6%), ampicillin (31.2%), and erythromycin (9.4%). All tested strains were sensitive to gentamicin. By multilocus sequence typing analysis, a total of 9 different sequence types were identified among 16 C. jejuni isolates. Campylobacter jejuni isolated from cecal content and carcass skin of the same farm or slaughter batch showed corresponding allelic profiles. Our data suggest that intense cross-contamination during the slaughter process led to a strong increase of Campylobacter prevalence on broiler skin compared with the prevalence in broiler ceca. To reduce Campylobacter prevalences on broiler skin, on-farm biosecurity measures need to be accompanied by control measures at the slaughterhouse to reduce fecal contamination of broiler skin and to minimize cross-contamination.

Invasive salmonellosis in urban Thai children: a ten-year review

BACKGROUND

Invasive, extraintestinal salmonellosis carries a significant burden of childhood morbidity especially among infants and young children in developing countries.

OBJECTIVES

To determine the clinical manifestations, outcomes, laboratory findings and antimicrobial susceptibility patterns in patients with invasive salmonellosis.

METHODS

A retrospective chart review was conducted among children 0-18 years of age diagnosed with invasive salmonellosis receiving care at Queen Sirikit National Institute of Child Health, Bangkok, Thailand, from 2001 to 2010.

RESULTS

We analyzed the records of 229 patients with culture-proven invasive salmonellosis. Sixty-three percent of cases had no documented underlying disease. Fever, diarrhea and respiratory symptoms were reported in 92%, 40% and 29% of cases, respectively. The spectrum of disease included isolated bacteremia (90%), clinical pneumonia (24.8%), bacteremia with meningitis (7.8%), septic arthritis (1.3%) and empyema thoracis (0.4%). Forty-seven of 57 cases presenting with clinical pneumonia had abnormal infiltrations on chest radiograph (20.5% of all cases). Despite the invasive nature of the illness, 53.1% of patients had a normal white blood cell count. Antimicrobial resistance was found among ampicillin (68.3%), chloramphenical (15.2%), trimethoprim-sulfamethoxazole (33.9%), ceftriaxone (17.4%) and ciprofloxacin (3%). The case fatality rate was 4.8%, 91% of whom had an underlying disease. Multivariate analysis indicated that age, underlying liver disease and presence of pneumonia were significant predictors of fatality.

CONCLUSIONS

Fever, diarrhea and respiratory symptoms were among the most common presenting symptoms of invasive nontyphoidal salmonellosis. Older age, hepatobiliary disease and presence of pneumonia were associated with increased risk of fatality. Resistance to third-generation cephalosporins poses a major concern for its use as empiric antimicrobial therapy for this condition.

PFGE, Lior serotype, and antimicrobial resistance patterns among Campylobacter jejuni isolated from travelers and US military personnel with acute diarrhea in Thailand, 1998-2003

Background

Campylobacter jejuni is a major cause of gastroenteritis worldwide. In Thailand, several strains of C. jejuni have been isolated and identified as major diarrheal pathogens among adult travelers. To study the epidemiology of C. jejuni in adult travelers and U.S. military personnel with acute diarrhea in Thailand from 1998-2003, strains of C. jejuni were isolated and phenotypically identified, serotyped, tested for antimicrobial susceptibility, and characterized using pulsed-field gel electrophoresis (PFGE).

Results

A total of 312 C. jejuni isolates were obtained from travelers (n = 46) and U.S. military personnel (n = 266) in Thailand who were experiencing acute diarrhea. Nalidixic acid and ciprofloxacin resistance was observed in 94.9% and 93.0% of the isolates, respectively. From 2001-2003, resistance to tetracycline (81.9%), trimethoprim-sulfamethoxazole (57.9%), ampicillin (28.9%), kanamycin (5.9%), sulfisoxazole (3.9%), neomycin (2.0%), and streptomycin (0.7%) was observed. Combined PFGE analysis showed considerable genetic diversity among the C. jejuni isolates; however, four PFGE clusters included isolates from the major Lior serotypes (HL: 36, HL: 11, HL: 5, and HL: 28). The PFGE analysis linked individual C. jejuni clones that were obtained at U.S. military exercises with specific antimicrobial resistance patterns.

Conclusions

In summary, most human C. jejuni isolates from Thailand were multi-resistant to quinolones and tetracycline. PFGE detected spatial and temporal C. jejuni clonality responsible for the common sources of Campylobacter gastroenteritis.

Prevalence of antimicrobial resistance among serotypes of Campylobacter jejuni isolates from cattle and poultry in Japan

Penner serotypes of C. jejuni in a total of 601 isolates from apparently healthy cattle, layer and broiler chickens in Japan were examined between 2001 and 2006. Predominant serotypes were B (O: 2, 19.1%), D (O: 4, 13.5%), Y (O: 37, 7.3%) and G (O: 8, 5.8%), whereas the remaining serotypes made up less than 5% of the total isolates. The frequency of ampicillin resistance in serotype G (65.6%) was significantly higher than in serotypes D (12.5%), B (11.2%), and Y (0%). Our results suggest that serotype is one factor contributing to the prevalence of ampicillin resistance in C. jejuni isolates.

Antimicrobial resistance in selected bacteria from poultry

This paper reviews the present state of antimicrobial resistance (AMR) in the zoonotic bacteria Salmonella, Campylobacter jejuni and Campylobacter coli, and in Escherichia coli from chickens and turkeys. For Salmonella, the frequencies and patterns of AMR vary depending on time, region, serovar, the particular farm, layers versus broilers, and the antimicrobial agent. There is usually a higher frequency of AMR in Salmonella from turkeys compared with Salmonella from chickens. Clonal and horizontal transmission of AMR occur and there is concern about the spread of transmissible plasmids that encode extended spectrum cephalosporinases. Resistance to fluoroquinolones is generally low. For Campylobacter, resistance to tetracycline is usually at moderate to high frequency, resistance to quinolones/fluoroquinolones varies from low to high, and resistance to macrolides is usually low. There are high levels of fluoroquinolone resistance in some countries. Avian pathogenic E. coli are often highly resistant, especially to tetracycline, streptomycin, and sulfonamides. Plasmid-mediated resistance is common. High levels of resistance to ciprofloxacin have been reported from China. Commensal E. coli from poultry have similar patterns of resistance but at lower frequencies. Integron associated resistance occurs commonly in Salmonella and E. coli but has not been detected in Campylobacter.

Key role of Mfd in the development of fluoroquinolone resistance in Campylobacter jejuni

Campylobacter jejuni is a major food-borne pathogen and a common causative agent of human enterocolitis. Fluoroquinolones are a key class of antibiotics prescribed for clinical treatment of enteric infections including campylobacteriosis, but fluoroquinolone-resistant Campylobacter readily emerges under the antibiotic selection pressure. To understand the mechanisms involved in the development of fluoroquinolone-resistant Campylobacter, we compared the gene expression profiles of C. jejuni in the presence and absence of ciprofloxacin using DNA microarray. Our analysis revealed that multiple genes showed significant changes in expression in the presence of a suprainhibitory concentration of ciprofloxacin. Most importantly, ciprofloxacin induced the expression of mfd, which encodes a transcription-repair coupling factor involved in strand-specific DNA repair. Mutation of the mfd gene resulted in an approximately 100-fold reduction in the rate of spontaneous mutation to ciprofloxacin resistance, while overexpression of mfd elevated the mutation frequency. In addition, loss of mfd in C. jejuni significantly reduced the development of fluoroquinolone-resistant Campylobacter in culture media or chickens treated with fluoroquinolones. These findings indicate that Mfd is important for the development of fluoroquinolone resistance in Campylobacter, reveal a previously unrecognized function of Mfd in promoting mutation frequencies, and identify a potential molecular target for reducing the emergence of fluoroquinolone-resistant Campylobacter.