Control of vancomycin-resistant enterococcus in health care facilities in a region

BACKGROUND

In late 1996, vancomycin-resistant enterococci were first detected in the Siouxland region of Iowa, Nebraska, and South Dakota. A task force was created, and in 1997 the assistance of the Centers for Disease Control and Prevention was sought in assessing the prevalence of vancomycin-resistant enterococci in the region's facilities and implementing recommendations for screening, infection control, and education at all 32 health care facilities in the region.

METHODS

The infection-control intervention was evaluated in October 1998 and October 1999. We performed point-prevalence surveys, conducted a case-control study of gastrointestinal colonization with vancomycin-resistant enterococci, and compared infection-control practices and screening policies for vancomycin-resistant enterococci at the acute care and long-term care facilities in the Siouxland region.

RESULTS

Perianal-swab samples were obtained from 1954 of 2196 eligible patients (89 percent) in 1998 and 1820 of 2049 eligible patients (89 percent) in 1999. The overall prevalence of vancomycin-resistant enterococci at 30 facilities that participated in all three years of the study decreased from 2.2 percent in 1997 to 1.4 percent in 1998 and to 0.5 percent in 1999 (P<0.001 by chi-square test for trend). The number of facilities that had had at least one patient with vancomycin-resistant enterococci declined from 15 in 1997 to 10 in 1998 to only 5 in 1999. At both acute care and long-term care facilities, the risk factors for colonization with vancomycin-resistant enterococci were prior hospitalization and treatment with antimicrobial agents. Most of the long-term care facilities screened for vancomycin-resistant enterococci (26 of 28 in 1998 [93 percent] and 23 of 25 in 1999 [92 percent]) and had infection-control policies to prevent the transmission of vancomycin-resistant enterococci (22 of 25 [88 percent] in 1999). All four acute care facilities had screening and infection-control policies for vancomycin-resistant enterococci in 1998 and 1999.

CONCLUSIONS

An active infection-control intervention, which includes the obtaining of surveillance cultures and the isolation of infected patients, can reduce or eliminate the transmission of vancomycin-resistant enterococci in the health care facilities of a region.

Rapid detection of group B streptococci in pregnant women at delivery

BACKGROUND

Group B streptococcal infections are an important cause of neonatal morbidity and mortality. A rapid method for the detection of this organism in pregnant women at the time of delivery is needed to allow early treatment of neonates.

METHODS

We studied the efficacy of two polymerase-chain-reaction (PCR) assays for routine screening of pregnant women for group B streptococci at the time of delivery. We obtained anal, vaginal, and combined vaginal and anal specimens from 112 pregnant women; in 57 women, specimens were obtained before and after the rupture of the amniotic membranes. The specimens were tested for group B streptococci by culture in a standard selective broth medium, with a conventional PCR assay, and with a new fluorogenic PCR assay.

RESULTS

Among the 112 women, the results of the culture of the combined vaginal and anal specimens were positive for group B streptococci in 33 women (29.5 percent). The two PCR assays detected group B streptococcal colonization in specimens from 32 of these 33 women: the one negative PCR result was in a sample obtained after the rupture of membranes. As compared with the culture results, the sensitivity of both PCR assays was 97.0 percent and the negative predictive value was 98.8 percent. Both the specificity and the positive predictive value of the two PCR assays were 100 percent. The length of time required to obtain results was 30 to 45 minutes for the new PCR assay, 100 minutes for the conventional PCR assay, and at least 36 hours for culture.

CONCLUSIONS

Colonization with group B streptococci can be identified rapidly and reliably by a PCR assay in pregnant women in labor both before and after the rupture of membranes.

A novel bacterial pathogen, Microbacterium nematophilum, induces morphological change in the nematode C. elegans

The Dar (deformed anal region) phenotype, characterized by a distinctive swollen tail, was first detected in a variant strain of Caenorhabditis elegans which appeared spontaneously in 1986 during routine genetic crosses [1,2]. Dar isolates were initially analysed as morphological mutants, but we report here that two independent isolates carry an unusual bacterial infection different from those previously described [3], which is the cause of the Dar phenotype. The infectious agent is a new species of coryneform bacterium, named Microbacterium nematophilum n. sp., which fortuitously contaminated cultures of C. elegans. The bacteria adhere to the rectal and post-anal cuticle of susceptible nematodes, and induce substantial local swelling of the underlying hypodermal tissue. The swelling leads to constipation and slowed growth in the infected worms, but the infection is otherwise non-lethal. Certain mutants of C. elegans with altered surface antigenicity are resistant to infection. The induced deformation appears to be part of a survival strategy for the bacteria, as C. elegans are potentially their predators.

Genetic dissimilarity of commensal strains of Candida spp. carried in different anatomical locations of the same healthy women

Candida spp. carriage and strain relatedness were assessed in 52 healthy women at 17 anatomical locations by using an isolation procedure which assesses carriage intensity and by using a computer-assisted DNA fingerprinting system which computes genetic similarity between strains on the basis of the patterns of Southern blots probed with the moderately repetitive sequence Ca3. Candida spp. were cultured from 73% of the test individuals, most frequently from the oral (56%), vulvovaginal (40%), and anorectal (24%) regions. Half of the test individuals with Candida spp. carried the organism simultaneously in more than one of the three general areas of carriage. Isolates from different body locations of the same individual were either completely unrelated, identical, or highly similar but nonidentical. In 11 cases in which Candida spp. were simultaneously isolated from the oral cavity and vaginal canal, seven pairs of isolates were genetically unrelated and four pairs were similar but nonidentical. In the latter cases, the isolate pairs each appear to have arisen by genetic divergence from a single progenitor. A comparison of the genetic relatedness of isolates from different individuals further uncovered a single strain which was vaginospecific in the Iowa City, Iowa area and reduced genetic diversity among vulvovaginal strains compared with those isolated from other body locations. These results suggest that strains adapt to different anatomical locations and, conversely, that in a healthy individual there is anatomical selection of vaginotropic, anotropic and orotropic strains of Candida spp.

Anorectal and vaginal carriage of group B streptococci during pregnancy

A longitudinal prospective study of carriage of group B streptococci during pregnancy was conducted in 2,540 women over a three-year period. Carriage was documented in 18% of the women by anorectal culture, in 4% by vaginal culture, and in 13% by simultaneously obtained anorectal and vaginal cultures (overall carriage rate, 35%). The rate and pattern of carriage were nearly identical from year to year. In sequential cultures in the second and third trimesters of 754 women, carriage rates were 31% and 28%, respectively; only 17% of the women were carriers in both trimesters. (1) Persistence of carriage was most common when the initial anorectal swabs were positive, (2) spread from the intestinal tract to the vagina occurred, and (3) the intestinal tract was commonly the primary site of acquisition in patients with previously negative cultures. The intestinal tract appears to be a primary reservoir for group B streptococci and the likely source of vaginal or urogenital colonization in pregnant women.

Rectoanal junction colonization of feedlot cattle by Escherichia coli O157:H7 and its association with supershedders and excretion dynamics

Feedlot cattle were observed for fecal excretion of and rectoanal junction (RAJ) colonization with Escherichia coli O157:H7 to identify potential "supershedders." RAJ colonization and fecal excretion prevalences were correlated, and E. coli O157:H7 prevalences and counts were significantly greater for RAJ samples. Based on a comparison of RAJ and fecal ratios of E. coli O157:H7/E. coli counts, the RAJ appears to be preferentially colonized by the O157:H7 serotype. Five supershedders were identified based on persistent colonization with high concentrations of E. coli O157:H7. Cattle copenned with supershedders had significantly greater mean pen E. coli O157:H7 RAJ and fecal prevalences than noncopenned cattle. Cumulative fecal E. coli O157:H7 excretion was also significantly higher for pens housing a supershedder. E. coli O157:H7/E. coli count ratios were higher for supershedders than for other cattle, indicating greater proportional colonization. Pulsed-field gel electrophoresis analysis demonstrated that isolates from supershedders and copenned cattle were highly related. Cattle that remained negative for E. coli O157:H7 throughout sampling were five times more likely to have been in a pen that did not house a supershedder. The data from this study support an association between levels of fecal excretion of E. coli O157:H7 and RAJ colonization in pens of feedlot cattle and suggest that the presence of supershedders influences group-level excretion parameters. An improved understanding of individual and population transmission dynamics of E. coli O157:H7 can be used to develop preslaughter- and slaughter-level interventions that reduce contamination of the food chain.

Rectoanal mucosal swab culture is more sensitive than fecal culture and distinguishes Escherichia coli O157:H7-colonized cattle and those transiently shedding the same organism

Enrichment and direct (nonenrichment) rectoanal mucosal swab (RAMS) culture techniques were developed and compared to traditional fecal culture for the detection of Escherichia coli O157:H7 in experimentally infected and naturally infected cattle. Holstein steers (n = 16) orally dosed with E. coli O157:H7 were sampled after bacterial colonization starting 15 days postinoculation. Enrichment RAMS cultures (70.31% positive) were more sensitive than enrichment fecal cultures with 10 g of feces (46.88% positive) at detecting E. coli O157:H7 (P < 0.01). Holstein bull calves (n = 15) were experimentally exposed to E. coli O157:H7 by penning them with E. coli O157:H7-positive calves. Prior to bacterial colonization (1 to 14 days postexposure), enriched fecal cultures were more sensitive at detecting E. coli O157:H7 than enriched RAMS cultures (P < 0.01). However, after colonization (40 or more days postexposure), the opposite was true and RAMS culture was more sensitive than fecal culture (P < 0.05). Among naturally infected heifers, enriched RAMS or fecal cultures were equally sensitive (P = 0.5), but direct RAMS cultures were more sensitive than either direct or enriched fecal cultures at detecting E. coli O157:H7 (P < 0.01), with 25 of 144, 4 of 144, and 10 of 108 samples, respectively, being culture positive. For both experimentally and naturally infected cattle, RAMS culture predicted the duration of infection. Cattle transiently shedding E. coli O157:H7 for <1 week were positive by fecal culture only and not by RAMS culture, whereas colonized animals (which were culture positive for an average of 26 days) were positive early on by RAMS culture. RAMS culture more directly measured the relationship between cattle and E. coli O157:H7 infection than fecal culture.

Anal and cervical intraepithelial neoplasia: possible parallel

This study evaluated prospectively the use of an endoscope in examination of the anal canal for the detection of premalignant lesions. All patients underwent endoscopy and anal epithelial biopsy; the biopsy samples were examined histologically and human papillomavirus (HPV) DNA hybridisation was done. No evidence of anal intraepithelial neoplasia (AIN) was found in 20 control patients with anal fissure or fistula. Of 82 patients with anal HPV infection, 23 had evidence of AIN. The prevalence of AIN was significantly higher among homosexual than among heterosexual men (17 of 28 vs 1 of 26) with anal HPV infection. Of 28 women with anal HPV infection, 10 had cervical intraepithelial neoplasia (CIN); 5 of the 10 also had AIN, whereas no woman had AIN in the absence of CIN. The study shows that AIN occurs and can be diagnosed endoscopically in a manner similar to CIN. Further detailed prospective studies on the natural history of AIN and of groups at risk are required.

Adenoviruses and pediatric gastroenteritis

Adenoviruses were found in 8.6% of 900 pediatric inpatients with diarrhea who were tested by electron microscopy of a fecal specimen and cell culture inoculation of a throat swab and an anal swab specimen. In 5.1% of these patients, including 13.5% of patients who were four through five months of age, adenovirus particles were visualized in the fecal specimen. Controlled study demonstrated that visualized adenoviruses, especially those that did not grow readily in conventional Hep-2 cell cultures, were significantly associated with diarrhea. About 80% of the visualized adenoviruses from patients with diarrhea or vomiting or both, including 94% of the viruses that grew in the 293 cell line but that did not grow readily in Hep-2 cultures, proved to be enteral adenoviruses--adenoviruses from either group F (type 40) or group G (type 41). Inpatients with gastroenteritis and confirmed enteral adenoviruses ranged in age from one through 16 months, with a median age of seven months. Enteral adenoviruses apparently are endemic in this locale, as one or more of these viruses have been found in every calendar month for nine successive years.

Identification and composition of the tonsillar and anal enterococcal and streptococcal flora of dogs and cats

Enterococcus faecalis was the most frequently isolated enterococcal species from anal swabs and tonsils of dogs and cats, although in the anal samples from dogs Ent. hirae was found almost as often as Ent. faecalis. Most Ent. faecium strains from dog tonsils differed from those associated with humans and other animals in that they fermented sorbitol. Typical Ent. avium as well as atypical Ent. avium-like strains were seen in dogs, while the related species Ent. raffinosus was associated with cat tonsils. Enterococcus cecorum also occurred mainly in cats. Certain atypical strains, presumptively identified as Ent. cecorum, shared characteristics with Ent. columbae. The most frequent streptococcal species in tonsils of cats and dogs were Streptococcus suis and Strep. canis. Streptococcus canis and Strep. bovis predominated in anal swabs. The canine Strep. suis differed from the common porcine strains in fermenting mannitol. Forty-seven of the 288 isolates examined could not be identified or related to known species. The characteristics of two groups of these bacteria, provisionally called 'Ton 31 group' and 'O7 group' are described.

How important is patient-to-patient transmission in extended-spectrum beta-lactamase Escherichia coli acquisition

BACKGROUND

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli is an emerging pathogen. The causal role of antibiotic selective pressure versus patient-to-patient transmission has not been assessed. The objective of this study was to quantify the amount of patient-to-patient transmission among patients who acquire an ESBL-producing E coli infection using perianal surveillance cultures in an intensive care unit (ICU) population.

METHODS

A prospective cohort of patients admitted between September 1, 2001, and September 1, 2004, to the medical and surgical ICUs at a tertiary care hospital was studied. Patients had perianal cultures on admission, weekly, and upon discharge. Strain typing by pulsed-field gel electrophoresis (PFGE) and epidemiologic criteria were used to quantify the amount of patient-to-patient transmission.

RESULTS

There were 1806 patients admitted to the ICUs. There were 74 patients who had ESBL-producing E coli on admission to the ICU and 23 patients who acquired ESBL-producing E coli. Among these 23 patients, there were 14 PFGE types, and 3 (13%) patient acquisitions were defined as patient-to-patient transmission by similar PFGE type and overlapping time in the hospital.

CONCLUSION

Our data suggest that patient-to-patient transmission is not an important cause of the acquisition of ESBL-producing E coli colonization in the ICU setting.

Immune status as a determinant of human papillomavirus detection and its association with anal epithelial abnormalities

One hundred and twenty Danish homosexual men were enrolled to characterize risk factors for anal type-specific human papillomavirus (HPV) expression and to examine its association with anal epithelial atypia. Detection of HPV strongly correlated with immunosuppression measured by T-lymphocyte subset markers and rose nearly linearly from 7.3% among subjects with CD4/CD8 ratios above 1.0 to 35.3% among those with a ratio below 0.4 (p trend = 0.003). No association was found between presence of HPV and a wide range of lifestyle factors including number of sex partners/year, smoking, alcohol consumption and illegal drug intake. However, self-reported history of anal condyloma in the past year was correlated with HPV (p less than 0.001). Simultaneous testing for presence of HPV in the oral cavity showed evidence of HPV 16,18 and 31,33,35. Anal smears were abnormal in 19.5% of the men and correlated strongly with presence of HPV (OR = 6.1, p less than 0.001). Type-specific associations were found with HPV 31/33/35 (OR = 8.5) and HPV 16/18 (OR = 3.1) only. The association remained significant after adjusting for immune status. Overall, HPV was detected in 50% of the cases with abnormal smears. However, HPV was found in all subjects with abnormal smears and a CD4/CD8 ratio below 0.4, compared to only 3 of 14 subjects with abnormal smears and a ratio greater than or equal to 1.3. In conclusion, (1) HPV may be missed in a substantial number of infected subjects with a normal immune system. This may have an impact on studies trying to describe risk factors for HPV transmission and its correlation with cancer development. (2) The finding of HPV 16,18 and 31,33,35 in the oral cavity makes oral-genital sexual activity at least a hypothetical route of transmission for these HPV types. (3) HPV appears to play a central role in the development of anal epithelial abnormality.

Colonization Status and Appropriate Antibiotic Therapy for Nosocomial Bacteremia Caused by Antibiotic-Resistant Gram-Negative Bacteria in an Intensive Care Unit

Objective:

Timely initiation of antibiotic therapy is crucial for severe infection. Appropriate antibiotic therapy is often delayed for nosocomial infections caused by antibiotic-resistant bacteria. The relationship between knowledge of colonization caused by antibiotic-resistant gram-negative bacteria (ABR-GNB) and rate of appropriate initial antibiotic therapy for subsequent bacteremia was evaluated.

Design:

Retrospective cohort study.

Setting:

Fifty-four-bed intensive care unit (ICU) of a university hospital. In this unit, colonization surveillance is performed through routine site-specific surveillance cultures (urine, mouth, trachea, and anus). Additional cultures are performed when presumed clinically relevant.

Patients:

ICU patients with nosocomial bacteremia caused by ABR-GNB.

Results:

Infectious and microbiological characteristics and rates of appropriate antibiotic therapy were compared between patients with and without colonization prior to bacteremia. Prior colonization was defined as the presence (detected ≥ 2 days before the onset of bacteremia) of the same ABR-GNB in colonization and subsequent blood cultures. During the study period, 157 episodes of bacteremia caused by ABR-GNB were suitable for evaluation. One hundred seventeen episodes of bacteremia (74.5%) were preceded by colonization. Appropriate empiric antibiotic therapy (started within 24 hours) was administered for 74.4% of these episodes versus 55.0% of the episodes that occurred without prior colonization. Appropriate therapy was administered within 48 hours for all episodes preceded by colonization versus 90.0% of episodes without prior colonization.

Conclusion:

Knowledge of colonization status prior to infection is associated with higher rates of appropriate therapy for patients with bacteremia caused by ABR-GNB (Infect Control Hosp Epidemiol 2005;26:575-579).

Interaction of human immunodeficiency and papilloma viruses: association with anal epithelial abnormality in homosexual men

During the 7th annual follow-up of our cohort of homosexual men in 1989, we tested the hypotheses that infection with human immunodeficiency virus (HIV) may enhance the expression of human papilloma virus (HPV) and that the development of anal epithelial abnormality is related to a biologic interaction between these two viruses. Overall, 41 (39%) of the 105 men had anal swabs positive for one or more genotypes of HPV 6/11, 16/18 or 31/33/35. Twenty-three (53%) of the 43 HIV-positive subjects harbored HPV compared to 18 (29%) of the 64 HIV-negative subjects (p = 0.012), including higher prevalence rates for HPV genotypes 16/18 (p = 0.01), 6/11 (p = 0.007), and 31/33/35 (p = 0.07). Multivariate logistic regression analysis of the HIV-positive subjects showed low CD4+ cell counts to be an independent risk factor for detection of HPV (p = 0.04) and in particular for HPV genotypes 31/33/35 (p = 0.02) and 6/11 (p = 0.07). In contrast, similar analysis of the HIV-negative subset showed that a positive antibody test for syphilis was associated with HPV (p = 0.03). Anal epithelial abnormalities were found in 13 (14%) of 92 technically adequate cytologic smears and were strongly associated with detection of any HPV genotypes by the dot-blot method (p = 0.01), and in particular with HPV genotypes 6/11 (p = 0.001). None of 15 subjects with HPV detected only by PCR had anal epithelial abnormality. We propose a viral interaction model, in which HIV-related immune deficiency allows reactivation of HPV, with a subsequent or concomitant appearance of epithelial abnormality.

Anal cancer and human papillomaviruses

Epidemiologic and clinical evidence has suggested a possible association between anal cancer and human papillomavirus (HPV) types that are known to be associated with cervical and other genital cancers. Using Southern blot and dot blot analysis, the authors examined 45 primary anal malignancies for HPV DNA types 6, 11, 16, and 18. HVP 16, DNA was detected in 23 of 41 (56 percent) anal squamous-cell carcinomas (SCC) and in the lymph-node metastases of two of these tumors. In addition, HPV 18 DNA was detected in 2/41 (5 percent) anal SCCs. Anal SCC contained no detectable HPV 6 or 11 DNA. The remaining four primary anal malignancies were not squamous carcinomas and did not contain any detectable HPV DNA. Nonmalignant anal epithelium and malignant rectal mucosa obtained from surgical patients undergoing hemorrhoidectomy and abdominoperineal excision of the rectum did not contain any detectable HPV DNA. HPV 16 DNA in anal cancer was predominantly integrated into the host cell DNA. In situ hybridization was used to demonstrate that HPV 16 DNA in anal SCC tissues is confined to the nuclei of carcinoma cells. The results of this investigation closely parallel similar studies of cervical cancer and lend support to the concept of the involvement of HPV 16 and 18 in the development of anal and genital squamous-cell carcinoma.

Characterization of the gut-associated microbiome in inflammatory pouch complications following ileal pouch-anal anastomosis

Introduction

Inflammatory complications following ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) are common and thought to arise through mechanisms similar to denovo onset inflammatory bowel disease. The aim of this study was to determine whether specific organisms in the tissue-associated microbiota are associated with inflammatory pouch complications.

Methods

Patients having previously undergone IPAA were recruited from Mount Sinai Hospital. Clinical and demographic information were collected and a pouchoscopy with biopsy of both the pouch and afferent limb was performed. Patients were classified based on post-surgical phenotype into four outcome groups: familial adenomatous polyposis controls (FAP), no pouchitis, pouchitis, and Crohn’s disease-like (CDL). Pyrosequencing of the 16S rRNA V1-V3 hypervariable region, and quantitative PCR for bacteria of interest, were used to identify organisms present in the afferent limb and pouch. Associations with outcomes were evaluated using exact and non-parametric tests of significance.

Results

Analysis at the phylum level indicated that Bacteroidetes were detected significantly less frequently (P<0.0001) in the inflammatory outcome groups (pouchitis and CDL) compared to both FAP and no pouchitis. Conversely, Proteobacteria were detected more frequently in the inflammatory groups (P=0.01). At the genus level, organisms associated with outcome were detected less frequently among the inflammatory groups compared to those without inflammation. Several of these organisms, including Bacteroides (P<0.0001), Parabacteroides (P≤2.2x10^-3), Blautia (P≤3.0x10^-3) and Sutterella (P≤2.5x10^-3), were associated with outcome in both the pouch and afferent limb. These associations remained significant even following adjustment for antibiotic use, smoking, country of birth and gender. Individuals with quiescent disease receiving antibiotic therapy displayed similar reductions in these organisms as those with active pouch inflammation.

Conclusions

Specific genera are associated with inflammation of the ileal pouch, with a reduction of typically ubiquitous organisms characterizing the inflammatory phenotypes.

Polymorphism of the migration of double-stranded RNA genome segments of reovirus isolates from humans, cattle, and mice

A series of 94 isolates of reovirus from humans, cattle, and mice, showed extensive variability in the patterns of migration of the ten double-stranded RNA genome segments. This variation was found in all three serotypes, and involved all ten genome segments, including the segment responsible for serological specificity. Although a single pattern was present among several samples isolated from individuals and collected at a single time and place, there were often multiple genetic variants of a single serotype present in a population. Samples isolated from widely different geographic origins or different mammalian hosts showed different patterns; samples from a single species from the same area over a period of time showed more limited variations. Among most isolates, the migration of the slowest S segment, the segment that encodes the hemagglutinin and is responsible for serological specificity in laboratory strains, was similar to reference strains for type 1 and type 3 isolates. However, the type 2 isolates showed considerable variation in this segment.

Escherichia coli O157:H7 colonization at the rectoanal junction of long-duration culture-positive cattle

Long-duration consistently Escherichia coli O157:H7 culture-positive cattle were euthanized and necropsied. Tissue and digesta from along the gastrointestinal tract (GIT) were cultured for the bacteria and examined histologically for lymphoid character. E. coli O157:H7 was detected only at the rectoanal junction mucosa and not at any other GIT location.

Prevalence of methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii in a long-term acute care facility

BACKGROUND

Patients in long-term acute care (LTAC) facilities often have many known risk factors for acquisition of antibiotic-resistant bacteria. However, the prevalence of resistance in these facilities has not been well described.

METHODS

We performed a single-day, point-prevalence study of a 180-bed, university-affiliated LTAC facility in Baltimore to assess the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii in the anterior nares, perirectal area, sputum, and wounds.

RESULTS

Among the 147 patients evaluated, we found a high prevalence of colonization by both MRSA (28%) and A baumannii (30%). Of the A baumannii isolates, 90% were susceptible to imipenem and 92% were susceptible to ampicillin-sulbactam. No isolates were resistant to both imipenem and ampicillin-sulbactam.

CONCLUSION

The high prevalence of resistance found in this study supports the need for increased surveillance of patients in the LTAC environment. The fact that these patients are often frequently transferred to tertiary care facilities also supports the need for coordination and collaboration among facilities within the same health care system and the broader geographic area.

Molecular detection of colistin resistance genes (mcr-1, mcr-2 and mcr-3) in nasal/oropharyngeal and anal/cloacal swabs from pigs and poultry

Antimicrobial resistance against colistin has emerged worldwide and is threatening the efficacy of colistin treatment of multi-resistant Gram-negative bacteria. In this study, PCRs were used to detect mcr genes (mcr-1, mcr-2, mcr-3) in 213 anal and 1,339 nasal swabs from pigs (n = 1,454) in nine provinces of China, and 1,696 cloacal and 1,647 oropharyngeal samples from poultry (n = 1,836) at live-bird markets in 24 provinces. The mcr-1 prevalences in pigs (79.2%) and geese (71.7%) were significantly higher than in chickens (31.8%), ducks (34.6%) and pigeons (13.1%). The mcr-2 prevalence in pigs was 56.3%, significantly higher than in chickens (5.5%), ducks (2.3%), geese (5.5%) and pigeons (0%). The mcr-3 prevalences in pigs (18.7%), ducks (13.8%) and geese (11.9%) were significantly higher than in chickens (5.2%) and pigeons (5.1%). In total, 173 pigs and three chickens were positive for all three mcr genes. The prevalences of the mcr were significantly higher in nasal/oropharyngeal swabs than in the anal /cloacal swabs. Phylogenetic studies identified 33 new mcr-2 variants and 12 new mcr-3 variants. This study demonstrates high prevalences of mcr in pigs and poultry in China, and indicates there is need for more thorough surveillance and control programs to prevent further selection of colistin resistance.

Reduced microbial diversity in adult survivors of childhood acute lymphoblastic leukemia and microbial associations with increased immune activation

BACKGROUND

Adult survivors of childhood cancers such as acute lymphoblastic leukemia (ALL) have health problems that persist or develop years after cessation of therapy. These late effects include chronic inflammation-related comorbidities such as obesity and type 2 diabetes, but the underlying cause is poorly understood.

RESULTS

We compared the anal microbiota composition of adult survivors of childhood ALL (N = 73) with healthy control subjects (N = 61). We identified an altered community with reduced microbial diversity in cancer survivors, who also exhibit signs of immune dysregulation including increased T cell activation and chronic inflammation. The bacterial community among cancer survivors was enriched for Actinobacteria (e.g. genus Corynebacterium) and depleted of Faecalibacterium, correlating with plasma concentrations of IL-6 and CRP and HLA-DR+CD4+ and HLA-DR+CD8+ T cells, which are established markers of inflammation and immune activation.

CONCLUSIONS

We demonstrated a relationship between microbial dysbiosis and immune dysregulation in adult ALL survivors. These observations suggest that interventions that could restore microbial diversity may ameliorate chronic inflammation and, consequently, development of late effects of childhood cancer survivors.