Incidence of diverse integrons and β-lactamase genes in environmental Enterobacteriaceae isolates from Jiaozhou Bay, China

Abstract

Environmental microbiology investigation was performed to determine the molecular diversity of b-lactamase genes among ampicillin-resistant bacteria from Jiaozhou Bay. b-lactamase genes were detected in 93.8% of the bacterial isolates identified as Enterobacteriaceae. The most frequently detected gene was bla TEM , followed by bla SHV , bla OAX-1 , bla MOX and bla CMY . Most of the isolates (68.8%) were positive for the intI1 integrase gene, and two isolates were also found for the intI2 gene. The dfr and aadA gene cassettes were predominant. Anthropogenic contamination from onshore sewage processing plants might contribute predominantly to the b-lactamase gene reservoir in the studied coastal waters. Environmental antibiotic-resistant bacteria and resistance genes may serve as bioindicators of coastal environmental quality or biotracers of the potential contamination sources. This is the first report of the prevalence and characterization of blactamase genes and integrons in coastal Enterobacteriaceae from China.

Environmental Factors Shape Sediment Anammox Bacterial Communities in Hypernutrified Jiaozhou Bay, China

“…The relative contribution of the various nitrite production or consumption processes is still poorly understood and needs to be further investigated in this coastal bay. Our previous studies indicate that the Jiaozhou Bay innermost stations A5 and Y1 were severely eutrophic and polluted and that stations A3 and C4 were also eutrophic and polluted to a certain degree (12)(13)(14)(15)71). Our current study correlates these findings with the fact that these sites, more or less, have distinct anammox bacterial assemblages (Fig.…”

“…Eutrophication has become its most serious environmental problem, along with red tides (harmful algal blooms), species loss, and contamination with toxic chemicals and harmful microbes (14,15,21,61,71). Due to different sources of pollution and various levels of eutrophication across Jiaozhou Bay (mariculture, municipal and industrial wastewater, crude oil shipyard, etc.…”

Multiple antibiotic resistances of enteric bacteria isolated from recreational coastal waters and oysters of the Caribbean Sea

“…Antibiotic resistance in enterobacteria and enterococci, partially primary or opportunistic pathogens, has increased dramatically in aquatic environments (Arvanitidou et al, 2001;Schwartz et al, 2003;Dang et al, 2008aDang et al, , 2008bWang et al, 2008). The majority of antibiotic resistance studies have focused on pathogenic bacterial populations, but it is known that commensal bacteria are also common reservoirs of antibiotic resistance genes (Salyers et al, 2004).…”

Bacterial composition and spatiotemporal variation in sediments of Jiaozhou Bay, China

“…Several small rivers form the major sources of discharged industrial and sewage wastewater bring excessive nutrients into the northeast of the bay (Shi et al 2011). Meanwhile, sporadic oil spilling from the commercial ports near the bay mouth, intensive maricultural practices at the north area, along with red tides all make the situation even worse (Wang et al 2008;Dang et al 2010b;Deng et al 2010). A wide spectrum of environmental conditions and accordingly a widely varying bacterial community structure have already drawn the JZB many research interests in recent years (Dang et al 2008a(Dang et al , b, 2009b(Dang et al , 2010b.…”