scholarly journals Genome sequencing links persistent outbreak of legionellosis in Sydney to an emerging clone of Legionella pneumophila ST211

2017 ◽  
Author(s):  
VJ Timms ◽  
R Rockett ◽  
NL Bachmann ◽  
E Martinez ◽  
Q Wang ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Legionella Pneumophila ◽  
Central Business District ◽  
Urban Setting ◽  
Potential Contribution ◽  
Cooling Towers ◽  
Main Cluster ◽  
Genome Recombination ◽  
Sources Of Infection ◽  
Business District

AbstractThe city of Sydney, Australia, experienced a persistent outbreak of Legionella pneumophila serogroup 1 (Lp1) pneumonia in 2016. To elucidate the source and bring the outbreak to a close we examined the genomes of clinical and environmental Lp1 isolates recovered over 7 weeks. A total of 48 isolates from patients and cooling towers were sequenced and compared using SNP-based, core-genome MLST and pangenome approaches. All three methods confirmed phylogenetic relatedness between isolates associated with outbreaks in the Central Business District (March and May) and Suburb 1. These isolates were designated “Main cluster” and consisted of isolates from two patients from the CBD March outbreak, one patient and one tower isolate from Suburb 1 and isolates from two cooling towers and three patients from the CDB May outbreak. All main cluster isolates were sequence type ST211 which has only ever been reported in Canada. Significantly, pangenome analysis identified mobile genetic elements containing a unique T4ASS that was specific to the main cluster and co-circulating clinical strains, suggesting a potential mechanism for increased fitness and persistence of the outbreak clone. Genome sequencing was key in deciphering the environmental sources of infection among the spatially and temporally coinciding cases of legionellosis in this highly populated urban setting. Further, the discovery of a unique T4ASS emphasises the potential contribution of genome recombination in the emergence of successful Lp1 clones.

scholarly journals Genome Sequencing Links Persistent Outbreak of Legionellosis in Sydney (New South Wales, Australia) to an Emerging Clone of Legionella pneumophila Sequence Type 211

2017 ◽  
Vol 84 (5) ◽  
Author(s):  
Verlaine J. Timms ◽  
Rebecca Rockett ◽  
Nathan L. Bachmann ◽  
Elena Martinez ◽  
Qinning Wang ◽  
...  
Keyword(s):  
Public Health ◽  
Genome Sequencing ◽  
Legionella Pneumophila ◽  
Secretion System ◽  
Sequence Type ◽  
Urban Setting ◽  
Cooling Towers ◽  
Main Cluster ◽  
Type Iv ◽  
Sydney Australia

ABSTRACT The city of Sydney, Australia, experienced a persistent outbreak of Legionella pneumophila serogroup 1 (Lp1) pneumonia in 2016. To elucidate the source and guide public health actions, the genomes of clinical and environmental Lp1 isolates recovered over 7 weeks were examined. A total of 48 isolates from human cases and cooling towers were sequenced and compared using single-nucleotide polymorphism (SNP)-based core-genome multilocus sequencing typing (MLST) and pangenome approaches. All three methods confirmed phylogenetic relatedness between isolates associated with outbreaks in the Central Business District (CBD) in March and May and those in suburb 1. These isolates were designated the “main cluster” and consisted of isolates from two patients from the CBD March outbreak, one patient and one tower isolate from suburb 1, and isolates from two cooling towers and three patients from the CBD May outbreak. All main cluster isolates were sequence type 211 (ST211), which previously has only been reported in Canada. Significantly, pangenome analysis identified mobile genetic elements containing a unique type IV A F-type secretion system (T4ASS), which was specific to the main cluster, and cocirculating clinical strains, suggesting a potential mechanism for increased fitness and persistence of the outbreak clone. Genome sequencing enabled linking of the geographically dispersed environmental sources of infection among the spatially and temporally coinciding cases of legionellosis in a highly populated urban setting. The discovery of a unique T4ASS emphasizes the role of genome recombination in the emergence of successful Lp1 clones. IMPORTANCE A new emerging clone has been responsible for a prolonged legionellosis outbreak in Sydney, Australia. The use of whole-genome sequencing linked two outbreaks thought to be unrelated and confirmed the outliers. These findings led to the resampling and subsequent identification of the source, guiding public health actions and bringing the outbreak to a close. Significantly, the outbreak clone was identified as sequence type 211 (ST211). Our study reports this ST in the Southern Hemisphere and presents a description of ST211 genomes from both clinical and environmental isolates. A unique mobile genetic element containing a type IV secretion system was identified in Lp1 ST211 isolates linked to the main cluster and Lp1 ST42 isolates that were cocirculating at the time of the outbreak.

scholarly journals Navigating the Kenya National Archives: Research and its Role in Kenyan Society

2005 ◽  
Vol 32 ◽  
pp. 445-455 ◽  
Author(s):  
Matthew Carotenuto ◽  
Katherine Luongo
Keyword(s):  
Central Business District ◽  
Urban Setting ◽  
Reading Room ◽  
Social Scientists ◽  
National Archives ◽  
Extensive Collection ◽  
Business District ◽  
Diverse Cultures ◽  
Rich History ◽  
Hilton Hotel

Situated at the edge of the central business district in downtown Nairobi, the Kenya National Archives (KNA) is a reservoir and living example of historical and ethnographic knowledge. Straddling the boundary between “tourist” Nairobi and “real” Nairobi, the KNA inhabits a space that transcends both function and class in a cosmopolitan, urban setting. The archives look out on the landmark Hilton Hotel, together with the swarms of up-market tourists and wealthy locals it attracts. On the KNA's rear, Tom Mboya street serves a modern gateway to the crushing, chaotic avenues and alleys that the vast majority of Nairobi's citizens tread daily as they depart from and return to the stark realities of Nairobi's eastern slums. Engulfed by the wailing horns of passing matatus and the rhythmic calls of street hawkers, the spaces inside and outside the archive offer a rich terrain for social scientists interested in both contemporary and historical Kenya.The composition of the KNA's clientele also reflects the boundaries that the archives span. Throughout the day, international tourists and local schoolchildren trickle into the groundfloor museum (currently undergoing a major renovation supported by the Ford Foundation) to view the extensive collection of artifacts and photographs representing Kenya's diverse cultures and rich history. Tucked away upstairs, a broad spectrum of patrons works and studies in the archives' reading room, using the KNA's resources for a variety of professional and personal projects.

scholarly journals Analysis of Urban Effects in Oklahoma City using a Dense Surface Observing Network

2016 ◽  
Vol 55 (3) ◽  
pp. 723-741 ◽  
Author(s):  
Xiao-Ming Hu ◽  
Ming Xue ◽  
Petra M. Klein ◽  
Bradley G. Illston ◽  
Sheng Chen
Keyword(s):  
Metropolitan Area ◽  
Land Surface ◽  
Critical Role ◽  
Central Business District ◽  
Temperature Inversion ◽  
Oklahoma City ◽  
Near Surface ◽  
Open Questions ◽  
The Stability ◽  
Business District

AbstractMany studies have investigated urban heat island (UHI) intensity for cities around the world, which is normally quantified as the temperature difference between urban location(s) and rural location(s). A few open questions still remain regarding the UHI, such as the spatial distribution of UHI intensity, temporal (including diurnal and seasonal) variation of UHI intensity, and the UHI formation mechanism. A dense network of atmospheric monitoring sites, known as the Oklahoma City (OKC) Micronet (OKCNET), was deployed in 2008 across the OKC metropolitan area. This study analyzes data from OKCNET in 2009 and 2010 to investigate OKC UHI at a subcity spatial scale for the first time. The UHI intensity exhibited large spatial variations over OKC. During both daytime and nighttime, the strongest UHI intensity is mostly confined around the central business district where land surface roughness is the highest in the OKC metropolitan area. These results do not support the roughness warming theory to explain the air temperature UHI in OKC. The UHI intensity of OKC increased prominently around the early evening transition (EET) and stayed at a fairly constant level throughout the night. The physical processes during the EET play a critical role in determining the nocturnal UHI intensity. The near-surface rural temperature inversion strength was a good indicator for nocturnal UHI intensity. As a consequence of the relatively weak near-surface rural inversion, the strongest nocturnal UHI in OKC was less likely to occur in summer. Other meteorological factors (e.g., wind speed and cloud) can affect the stability/depth of the nighttime boundary layer and can thus modulate nocturnal UHI intensity.

Building use by urban commensal avifauna in Melbourne central business district, Australia

2017 ◽  
Vol 117 (3) ◽  
pp. 284-289 ◽  
Author(s):  
Melissa Pike ◽  
Dirk H. R. Spennemann ◽  
Maggie J. Watson
Keyword(s):  
Central Business District ◽  
Business District
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