Assessment of contaminants, health and survival of migratory shorebirds in natural versus artificial wetlands - The potential of wastewater treatment plants as alternative habitats.

The rapid destruction of natural wetland habitats over past decades has been partially offset by an increase in artificial wetlands. However, these also include wastewater treatment plants, which may pose a pollution risk to the wildlife using them. We studied two long-distance Arctic-breeding migratory shorebird species, curlew sandpiper (Calidris ferruginea, n = 69) and red-necked stint (Calidris ruficollis, n = 103), while on their Australian non-breeding grounds using an artificial wetland at a wastewater treatment plant (WTP) and a natural coastal wetland. We compared pollutant exposure (elements and per- and poly-fluoroalkyl substances/PFASs), disease (avian influenza), physiological status (oxidative stress) of the birds at the two locations from 2011 to 2020, and population survival from 1978 to 2019. Our results indicated no significant differences in blood pellet pollutant concentrations between the habitats except mercury (WTP median: 224 ng/g, range: 19-873 ng/g; natural wetland: 160 ng/g, 22-998 ng/g) and PFASs (total PFASs WTP median: 85.1 ng/g, range: <0.01-836 ng/g; natural wetland: 8.02 ng/g, <0.01-85.3 ng/g) which were higher at the WTP, and selenium which was lower at the WTP (WTP median: 5000 ng/g, range: 1950-34,400 ng/g; natural wetland: 19,200 ng/g, 4130-65,200 ng/g). We also measured higher blood o,o'-dityrosine (an indicator of protein damage) at the WTP. No significant differences were found for adult survival, but survival of immature birds at the WTP appeared to be lower which could be due to higher dispersal to other wetlands. Interestingly, we found active avian influenza infections were higher in the natural habitat, while seropositivity was higher in the WTP, seemingly not directly related to pollutant exposure. Overall, we found limited differences in pollutant exposure, health and survival of the shorebirds in the two habitats. Our findings suggest that appropriately managed wastewater treatment wetlands could provide a suitable alternative habitat to these migratory species, which may aid in curbing the decline of shorebird populations from widespread habitat loss.

Thermal adaptation best explains Bergmann's and Allen's Rules across ecologically diverse shorebirds.

Bergmann's and Allen's rules state that endotherms should be larger and have shorter appendages in cooler climates. However, the drivers of these rules are not clear. Both rules could be explained by adaptation for improved thermoregulation, including plastic responses to temperature in early life. Non-thermal explanations are also plausible as climate impacts other factors that influence size and shape, including starvation risk, predation risk, and foraging ecology. We assess the potential drivers of Bergmann's and Allen's rules in 30 shorebird species using extensive field data (>200,000 observations). We show birds in hot, tropical northern Australia have longer bills and smaller bodies than conspecifics in temperate, southern Australia, conforming with both ecogeographical rules. This pattern is consistent across ecologically diverse species, including migratory birds that spend early life in the Arctic. Our findings best support the hypothesis that thermoregulatory adaptation to warm climates drives latitudinal patterns in shorebird size and shape.

Horizontal transfer of the blaNDM-1 gene to Pseudomonas aeruginosa and Acinetobacter baumannii in biofilms.

Horizontal gene transfer has contributed to the global spread of the blaNDM-1 gene. Multiple studies have demonstrated plasmid transfer of blaNDM-1 between Gram-negative bacteria, primarily Enterobacteriaceae species, but conjugational transfer of natural blaNDM-1 plasmids from Enterobacteriaceae into Pseudomonas aeruginosa and Acinetobacter baumannii has not previously been shown. As P. aeruginosa and A. baumannii are both typically strong biofilm formers, transfer of natural blaNDM-1 plasmids could potentially occur more readily in this environment. To determine whether natural blaNDM-1 plasmids could transfer to P. aeruginosa or A. baumannii in biofilms, three clinical and environmental Enterobacteriaceae strains carrying NDM-1-encoding plasmids of different incompatibility types were mated with E. coli J53, producing E. coli J53- blaNDM-1 transconjugants. Subsequently, dual-species biofilms were created using the E. coli J53 transconjugants as plasmid donors and either P. aeruginosa or A. baumannii as recipients. Biofilm transfer of NDM-encoding plasmids to P. aeruginosa and A. baumannii was successful from one and two E. coli J53- blaNDM-1 transconjugants, respectively. This demonstrates the potential for the spread of blaNDM-1, genes to P. aeruginosa and A. baumannii in clinical and environmental settings.

Preparedness for physiotherapy in private practice: Novices identify key factors in an interpretive description study.

BACKGROUND: Physiotherapists in Australia deliver services to a diverse range of clients, across many settings, however little research exists examining graduate preparedness for practice, even in the populous field of private practice. OBJECTIVES: To explore novice physiotherapist perspectives on preparedness for work in private practice. DESIGN: The qualitative approach of interpretive description was used to guide in-depth interviews with 8 novice physiotherapists from 3 universities working in 5 private practices in Melbourne. METHODS: All interviews were digitally recorded, transcribed verbatim and analyzed thematically. FINDINGS: Four main themes influencing graduate preparedness for work in private practice were identified: 1) non-curricular experiences (e.g. sports training) 2) elective curricular: practicum experiences; 3) curricular: attainment of skills specific to private practice; and 4) the private practice setting: supportive colleagues. This combination of non-curricular, curricular, and practice setting factors offered the necessary scaffolding for the graduates to report feeling prepared for work in private practice. CONCLUSIONS: Non-curricular activities, radiological instruction, clinical placements, building supportive colleague relations and professional development in private practice are recommended as potential means of building preparedness in novice therapists. Findings have implications for physiotherapy students, educators and private practice clinics looking to recruit new graduates.

Development and field evaluation of a method for detecting carbapenem-resistant bacteria in drinking water.

In this study, a fluorogenic heterotrophic plate count test for drinking water was modified in order to detect the presence of carbapenem-resistant bacteria. Antimicrobial agents and concentrations were selected based on recoveries of known carbapenem-resistant and carbapenem-susceptible strains inoculated into simulated samples. The modified method was field-tested on 19 drinking water samples from the New Delhi, India distribution system. Samples exhibiting fluorescence indicated bacterial growth in the presence of the supplemented antimicrobial agents, and organisms from these samples were cultured. Twenty-one Gram-negative isolates were identified from nine of the 19 samples and the meropenem minimum inhibitory concentrations were determined. Ultimately, eight carbapenem-resistant organisms were isolated from five sampling sites within the New Delhi water distribution system.

Impacts of culture-independent diagnostic practices on public health surveillance for bacterial enteric pathogens.

For decades, culture has been the mainstay of diagnostic testing for bacterial enteric pathogens. This paradigm is changing as clinical laboratories adopt culture-independent methods, such as antigen-based tests and nucleic acid-based assays. Public health surveillance for enteric infections addresses 4 interrelated but distinct objectives: case investigation for localized disease control; assessment of disease burden and trends to prioritize and assess impact of population-based control measures; outbreak detection; and microbiologic characterization to improve understanding of pathogens, their virulence mechanisms, and epidemiology. We summarize the challenges and opportunities that culture-independent tests present and suggest strategies, such as validation studies and development of culture-independent tests compatible with subtyping, that could be adopted to ensure that surveillance remains robust. Many of these approaches will require time and resources to implement, but they will be necessary to maintain a strong surveillance system. Public health practitioners must clearly explain the value of surveillance, especially how outbreak detection benefits the public, and collaborate with all stakeholders to develop solutions.

Laboratory practices for the identification of Shiga toxin-producing Escherichia coli in the United States, FoodNet sites, 2007.

Clinical laboratory practices affect patient care and disease surveillance. It is recommended that laboratories routinely use both culture for Escherichia coli O157 and a method that detects Shiga toxins (Stx) to identify all Stx-producing E. coli (STEC) and that labs send broths or isolates to a public health laboratory. In 2007, we surveyed laboratories serving Foodborne Diseases Active Surveillance Network sites that performed on-site enteric disease diagnostic testing to determine their culture and nonculture-based testing practices for STEC identification. Our goals were to measure changes over time in laboratory practices and to compare reported practices with published recommendations. Overall, 89% of laboratories used only culture-based methods, 7% used only Stx enzyme immunoassay (EIA), and 4% used both Stx EIA and culture-based methods. Only 2% of laboratories reported simultaneous culture for O157 STEC and use of Stx EIA. The proportion that ever used Stx EIA increased from 6% in 2003 to 11% in 2007. The proportion that routinely tested all specimens with at least one method was 66% in 2003 versus 71% in 2007. Reference laboratories were less likely than others to test all specimens routinely by one or more of these methods (48% vs. 73%, p=0.03). As of 2007, most laboratories complied with recommendations for O157 STEC testing by culture but not with recommendations for detection of non-O157 STEC. The proportion of laboratories that culture stools for O157 STEC has changed little since 2003, whereas testing for Stx has increased.

Shiga toxin-producing Escherichia coli (STEC) in Tennessee: surveillance and current clinical laboratory practices.

Since joining the Centers for Disease Control and Prevention's (CDC) Foodborne Diseases Active Surveillance Network (FoodNet) in 1999, Tennessee has conducted active surveillance for foodborne pathogens including Shiga toxin-producing E. coli (STEC). The number of STEC infections has increased in recent years in the United States, including Tennessee, due partly to changes in clinical laboratories practices including non-culture based testing methods. Despite increased reporting, STEC infections are likely under-recognized in Tennessee. A 2007 statewide laboratory survey indicated that less than half of clinical laboratories test for STEC on-site. Among these, only nine reported using non-culture based methods. Only one clinical laboratory reported simultaneous culture for STEC O157 and testing with an assay that detects Shiga toxins for non-O157 STEC as recommended by the CDC. Adoption of CDC recommendations coupled with timely and complete reporting will enhance public health surveillance, outbreak investigations and interventions to prevent STEC infection.

Recommendations for diagnosis of shiga toxin--producing Escherichia coli infections by clinical laboratories.

Shiga toxin--producing Escherichia coli (STEC) are a leading cause of bacterial enteric infections in the United States. Prompt, accurate diagnosis of STEC infection is important because appropriate treatment early in the course of infection might decrease the risk for serious complications such as renal damage and improve overall patient outcome. In addition, prompt laboratory identification of STEC strains is essential for detecting new and emerging serotypes, for effective and timely outbreak responses and control measures, and for monitoring trends in disease epidemiology. Guidelines for laboratory identification of STEC infections by clinical laboratories were published in 2006. This report provides comprehensive and detailed recommendations for STEC testing by clinical laboratories, including the recommendation that all stools submitted for routine testing from patients with acute community-acquired diarrhea (regardless of patient age, season of the year, or presence or absence of blood in the stool) be simultaneously cultured for E. coli O157:H7 (O157 STEC) and tested with an assay that detects Shiga toxins to detect non-O157 STEC. The report also includes detailed procedures for specimen selection, handling, and transport; a review of culture and nonculture tests for STEC detection; and clinical considerations and recommendations for management of patients with STEC infection. Improving the diagnostic accuracy of STEC infection by clinical laboratories should ensure prompt diagnosis and treatment of these infections in patients and increase detection of STEC outbreaks in the community.

Evaluation of polymerase chain reaction for group B streptococcus detection using an improved culture method.

OBJECTIVE: The administration of antibiotic prophylaxis to laboring women who harbor Group B streptococci (GBS) depends on identification of carriers. We sought to evaluate the diagnostic accuracy of real-time polymerase chain reaction (PCR) for detection of GBS using a more stringent culture method. METHODS: Two swabs were used simultaneously to obtain rectovaginal GBS samples from consenting women. One swab was analyzed using a stringent, validated culture technology, which included direct plating onto selective agar and inoculation of a selective broth. The other swab was used for a commercial real-time PCR assay, which uses amplification to detect the presence of the cfb gene sequence of GBS DNA. We calculated the assay accuracy using sensitivity and specificity. RESULTS: A total of 233 samples were available. Both the culture and PCR methods were positive for 59 and negative for 157 patients. The culture method was positive and PCR was negative in 9 patients. The culture was negative and the PCR positive for 8 patients. The sensitivity of the PCR assay was 86.8% and specificity was 95.2%. The positive predictive value was 88.1% and the negative predictive value was 94.6%. CONCLUSION: Although a rapid PCR assay may be useful to determine GBS status in the urgent intrapartum setting, the false-negative rate of 13.2% for the real-time PCR assay prohibits its use for standard GBS screening in the office.

Tolerance to vancomycin in pneumococci: detection with a molecular marker and assessment of clinical impact.

BACKGROUND: Vancomycin is often added to therapy for meningitis caused by Streptococcus pneumoniae. Tolerant bacteria without classic resistance that escape killing by multiple antibiotics have been reported sporadically. We determined the prevalence of tolerance to vancomycin in pneumococci and its effect on the outcome of meningitis. METHODS: Archival samples of 215 nasopharyngeal (NP) and 113 meningitis isolates were tested for the killing efficacy of vancomycin. Specific DNA sequence changes in a transporter locus were identified for tolerant isolates. Similar tests were conducted prospectively on 517 NP isolates from healthy children. RESULTS: In archival isolates, tolerance to vancomycin was detected in 3.7% of NP and 10.6% of invasive isolates. Patients with meningitis caused by tolerant isolates had a worse estimated 30-day survival than did patients with meningitis caused by nontolerant isolates (49% vs. 86%; P = .048); 62.5% of tolerant archival NP isolates harbored a specific sequence change for pep27 and vex2 (P = .021). Prospective analysis of 517 carriage isolates indicated that 8.1% were tolerant to vancomycin and that 82.1% of tolerant isolates harbored the specified marker gene sequences (P = .001). CONCLUSIONS: Tolerance to vancomycin exists in the population of pneumococci. Tolerant isolates are associated with meningitis of increased mortality, and these isolates can be tracked by specific marker sequences in 2 genes.