In the dairy cattle industry, Holstein and Jersey are the breeds most commonly used for production. They differ in performance by various traits, such as body size, milk production, and milk composition. With increased concerns about the impact of agriculture on climate change, potential differences in other traits, such as methane emission, also need to be characterized further. Since methane is produced in the rumen by methanogenic archaea, we investigated whether the population structure of methanogen communities would differ between Holsteins and Jerseys. Breed-specific rumen methanogen 16S rRNA gene clone libraries were constructed from pooled PCR products obtained from lactating Holstein and Jersey cows, generating 180 and 185 clones, respectively. The combined 365 sequences were assigned to 55 species-level operational taxonomic units (OTUs). Twenty OTUs, representing 85% of the combined library sequences, were common to both breeds, while 23 OTUs (36 sequences) were found only in the Holstein library and 12 OTUs (18 sequences) were found only in the Jersey library, highlighting increased diversity in the Holstein library. Other differences included the observation that sequences with species-like sequence identity to Methanobrevibacter millerae were represented more highly in the Jersey breed, while Methanosphaera-related sequences and novel uncultured methanogen clones were more frequent in the Holstein library. In contrast, OTU sequences with species-level sequence identity to Methanobrevibacter ruminantium were represented similarly in both libraries. Since the sampled animals were from a single herd consisting of two breeds which were fed the same diet and maintained under the same environmental conditions, the differences we observed may be due to differences in host breed genetics.

OBJECTIVES: To describe the initial clinical response and care escalation needs for children with urinary tract infections (UTIs) resistant to third-generation cephalosporins while on discordant antibiotics. METHODS: We performed a retrospective study of children <18 years old presenting to an acute care setting of 5 children’s hospitals and a large managed care organization from 2012 to 2017 with third-generation cephalosporin-resistant UTIs (defined as the growth of ≥50 000 colony-forming units per mL of Escherichia coli or Klebsiella spp. nonsusceptible to ceftriaxone with a positive urinalysis). We included children started on discordant antibiotics who had follow-up when culture susceptibilities resulted. Outcomes were escalation of care (emergency department visit, hospital admission, or ICU transfer while on discordant therapy) and clinical response at follow-up (classified as improved or not improved). RESULTS: Of the 316 children included, 78% were girls and the median age was 2.4 years (interquartile range 0.6–6.5). Children were evaluated in the emergency department (56%) or clinic (43%), and 90% were started on a cephalosporin. A total of 7 of 316 children (2.2%; 95% confidence interval 0.8%–4.5%) experienced escalation of care. For the 230 children (73%) with clinical response recorded, 192 of 230 (83.5%; 95% confidence interval 78.0%–88.0%) experienced clinical improvement. In children with repeat urine testing while on discordant therapy, pyuria improved or resolved in 16 of 19 (84%) and urine cultures sterilized in 11 of 17 (65%). CONCLUSIONS: Most children with third-generation cephalosporin-resistant UTIs started on discordant antibiotics experienced initial clinical improvement, and few required escalation of care. Our findings suggest that narrow-spectrum empiric therapy is appropriate while awaiting final urine culture results.

Management of pulmonary complications after hematopoietic stem cell transplantation (HSCT) often includes bronchoalveolar lavage (BAL), but the diagnostic yield of BAL remains unclear in pediatric HSCT patients. We reviewed the records of 78 allogeneic and 11 autologous transplant recipients who underwent BAL after HSCT at St. Jude Children's Research Hospital (1990-2002). We analyzed donor and recipient information, clinical variables, adverse events during bronchoscopy, outcome, and medical management at the time of the procedure to determine the diagnostic yield of BAL and factors that affect its success. Seventy-eight allogeneic and 11 autologous transplant recipients underwent BAL at a median of 68 days (range, 6-528 days) and 23 days (range, 6-705 days) after HSCT, respectively. The median age at the time of BAL was 12.2 years (0.8-23.5 years) in allogeneic patients and 16.9 years (4.8-26.2 years) in autologous patients. The most common indications for BAL in both populations were fever, hypoxia, and abnormality on chest auscultation. BAL identified an etiology in 53 allogeneic (67.9%) and 7 autologous (63.6%) patients (BAL positive); only 1 etiology was identified in 30 of the 53 allogeneic patients (56.6%). The most common finding was bacterial infection in both allogeneic (59.0%) and autologous (71.4%) patients. Of 39 allogeneic patients who had concurrent extrapulmonary infection, 30 (76.9%) had a positive BAL. Seven (9.0%) allogeneic patients experienced hypoxia (generally transient) during bronchoscopy. Approximately 68% of those with a positive BAL were receiving immunosuppressive therapy, whereas 96% of patients with a negative BAL were receiving immunosuppressive therapy (P = .008). Further, 26.4% of the BAL-positive cohort had grade II-IV acute graft-versus-host disease (aGVHD), whereas 60% of the BAL-negative group had grade II-IV aGVHD (P = .004). In our experience, the safety and diagnostic yield of BAL in this set of patients is relatively high, but the likelihood of informative findings is reduced among allogeneic recipients with grade II-IV aGVHD and those receiving immunosuppressive therapy.

Background Third-generation cephalosporin-resistant urinary tract infections (UTIs) often have limited oral antibiotic options with some children receiving prolonged parenteral courses. Our objectives were to determine predictors of long parenteral therapy and the association between parenteral therapy duration and UTI relapse in children with third-generation cephalosporin-resistant UTIs. Methods We conducted a multisite retrospective cohort study of children <18 years presenting to acute care at 5 children’s hospitals and a large managed care organization from 2012 to 2017 with a third-generation cephalosporin-resistant UTI from Escherichia coli or Klebsiella spp. Long parenteral therapy was ≥3 days and short/no parenteral therapy was 0–2 days of concordant parenteral antibiotics. Discordant therapy was antibiotics to which the pathogen was non-susceptible. Relapse was a UTI from the same organism within 30 days. Results Of the 482 children included, 81% were female and the median age was 3.3 years (interquartile range: 0.8-8). Fifty-four children (11.2%) received long parenteral therapy (median duration: 7 days). Predictors of long parenteral therapy included age <2 months (adjusted odds ratio [aOR] 67.3; 95% confidence interval [CI]: 16.4-275.7), limited oral antibiotic options (aOR 5.9; 95% CI: 2.8-12.3), and genitourinary abnormalities (aOR 5.4; 95% CI: 1.8-15.9). UTI relapse occurred in 1 of the 54 (1.9%) children treated with long parenteral therapy and in 6 of the 428 (1.5%) children treated with short/no parenteral therapy (P = .57). Of the 105 children treated exclusively with discordant antibiotics, 3 (2.9%, 95% CI: 0.6%-8.1%) experienced UTI relapse. Conclusions Long parenteral therapy was associated with age <2 months, limited oral antibiotic options, and genitourinary abnormalities. UTI relapse was rare and not associated with duration of parenteral therapy. For UTIs with limited oral options, further research is needed on the effectiveness of continued discordant therapy.