Role of Copper Efflux in Pneumococcal Pathogenesis and Resistance to Macrophage-Mediated Immune Clearance

Johnson, Michael D. L.; Kehl-Fie, Thomas E.; Klein, R F; Kelly, Jacqueline; Burnham, Corinna; Mann, Beth; Rosch, Jason W.

doi:10.1128/iai.03015-14

Cited by 73 publications

(92 citation statements)

References 51 publications

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“…While our work demonstrates urinary Cu mobilization via ceruloplasmin during UTI with Gram-negative pathogens, whether the Cu mobilization response is conserved during UTI with Gram-positive pathogens remains to be examined. Mutants lacking Cu detoxification systems in diverse pathogens, including Cryptococcus neoformans (a fungus), K. pneumoniae, Mycobacterium tuberculosis, Salmonella enterica serovar Typhimurium, Streptococcus pneumoniae, and UPEC, are attenuated in animal models of infection (11,(26)(27)(28)(29)(30)(31). Our results presented here elucidate the protective role of Cu in the pathogenesis of UTI.…”

Section: Discussionmentioning

confidence: 65%

Copper Is a Host Effector Mobilized to Urine during Urinary Tract Infection To Impair Bacterial Colonization

et al. 2017

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Urinary tract infection (UTI) is a major global infectious disease affecting millions of people annually. Human urinary copper (Cu) content is elevated during UTI caused by uropathogenic Escherichia coli (UPEC). UPEC upregulates the expression of Cu efflux genes during clinical UTI in patients as an adaptive response to host-derived Cu. Whether Cu is mobilized to urine as a host response to UTI and its role in protection against UTI remain unresolved. To address these questions, we tested the hypothesis that Cu is a host effector mobilized to urine during UTI to limit bacterial growth. Our results reveal that Cu is mobilized to urine during UTI caused by the major uropathogens Proteus mirabilis and Klebsiella pneumoniae, in addition to UPEC, in humans. Ceruloplasmin, a Cu-containing ferroxidase, is found at higher levels in UTI urine than in healthy control urine and serves as the molecular source of urinary Cu during UTI. Our results demonstrate that ceruloplasmin decreases the bioavailability of iron in urine by a transferrin-dependent mechanism. Experimental UTI with UPEC in nonhuman primates recapitulates the increased urinary Cu content observed during clinical UTI. Furthermore, Cu-deficient mice are highly colonized by UPEC, indicating that Cu is involved in the limiting of bacterial growth within the urinary tract. Collectively, our results indicate that Cu is a host effector that is involved in protection against pathogen colonization of the urinary tract. Because urinary Cu levels are amenable to modulation, augmentation of the Cu-based host defense against UTI represents a novel approach to limiting bacterial colonization during UTI. KEYWORDS UTI, urinary tract infection, uropathogenic E. coli, UPEC, copper, ceruloplasmin U rinary tract infection (UTI) is an extremely common infectious disease in the UnitedStates and around the world (1, 2). In the United States alone, UTI leads to 11 million physician visits, 1.7 million emergency room visits, and 470,000 hospitalizations annually, with a direct cost of $3.5 billion (2). Infection of the urinary bladder (cystitis) is the most common form of UTI, whereas kidney infection (pyelonephritis), bacteremia, and sepsis are less common but more serious outcomes of UTI (3, 4). Women are four times as likely to develop UTI as men are because of anatomic differences (4). Children, the elderly, and individuals with catheters, anatomic and physiologic abnormalities of the urinary tract, uroliths, or diabetes mellitus are also highly susceptible to UTI (4).Uropathogenic Escherichia coli (UPEC) is the etiological agent in ϳ85% of the cystitis cases in otherwise healthy people (3). Free-living, adherent, biofilm, and intracellular forms of UPEC are found in the urinary bladder (5, 6). UPEC utilizes multiple virulence factors, including type 1 fimbriae, P fimbriae, flagella, toxins, and iron acquisition systems, to cause UTI (2, 7). In addition to UPEC, Klebsiella pneumoniae and Proteus

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Section: Discussionmentioning

confidence: 65%

Copper Is a Host Effector Mobilized to Urine during Urinary Tract Infection To Impair Bacterial Colonization

et al. 2017

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“…S. pyogenes also shared sequence identity with S. pneumoniae cop operon-encoded proteins (38% identity to CopY and 44% to CopA) but lacked CupA. CupA, which plays a role in copper resistance in S. pneumoniae (13,22), has 33% identity to a hypothetical protein, Spy_0115, of unknown function in S. pyogenes MGAS5005.…”

Section: S Pyogenes Clinical Isolates Contain a Cop Operon-like Locusmentioning

confidence: 99%

“…In each of these organisms, the cop operon encodes a copper-transporting CPx-type ATPase (CopA/CopB), a copper-responsive repressor that represses the operon under conditions of low copper concentrations (CopY/CopR), and a copper chaperone that shuttles copper intracellularly (CopZ) (8,(13)(14)(15)(16)(17). Animal studies have demonstrated that deletion of a coppertransporting ATPase results in decreased survival of Mycobacterium tuberculosis (18), Pseudomonas aeruginosa (19), Listeria monocytogenes (20), Salmonella enterica serovar Typhimurium (21), and S. pneumoniae (13,22).…”

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confidence: 99%

Copper Tolerance and Characterization of a Copper-Responsive Operon, copYAZ , in an M1T1 Clinical Strain of Streptococcus pyogenes

et al. 2015

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Infection with Streptococcus pyogenes is associated with a breadth of clinical manifestations ranging from mild pharyngitis to severe necrotizing fasciitis. Elevated levels of intracellular copper are highly toxic to this bacterium, and thus, the microbe must tightly regulate the level of this metal ion by one or more mechanisms, which have, to date, not been clearly defined. In this study, we have identified two virulence mechanisms by which S. pyogenes protects itself against copper toxicity. We defined a set of putative genes, copY (for a regulator), copA (for a P1-type ATPase), and copZ (for a copper chaperone), whose expression is regulated by copper. Our results indicate that these genes are highly conserved among a range of clinical S. pyogenes isolates. The copY, copA, and copZ genes are induced by copper and are transcribed as a single unit. Heterologous expression assays revealed that S. pyogenes CopA can confer copper tolerance in a copper-sensitive Escherichia coli mutant by preventing the accumulation of toxic levels of copper, a finding that is consistent with a role for CopA in copper export. Evaluation of the effect of copper stress on S. pyogenes in a planktonic or biofilm state revealed that biofilms may aid in protection during initial exposure to copper. However, copper stress appears to prevent the shift from the planktonic to the biofilm state. Therefore, our results indicate that S. pyogenes may use several virulence mechanisms, including altered gene expression and a transition to and from planktonic and biofilm states, to promote survival during copper stress. IMPORTANCEBacterial pathogens encounter multiple stressors at the host-pathogen interface. This study evaluates a virulence mechanism(s) utilized by S. pyogenes to combat copper at sites of infection. A better understanding of pathogen tolerance to stressors such as copper is necessary to determine how host-pathogen interactions impact bacterial survival during infections. These insights may lead to the identification of novel therapeutic targets that can be used to address antibiotic resistance.

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“…In the case of Fe(II), one aspect of the bacterial peroxide stress response involves the decreased expression of Fe uptake systems and the increased expression of Fe storage proteins that effectively sequester Fe and thus prevent prooxidant activity (12)(13)(14). In contrast, copper concentrations within the bacterial cell are held very low as a consequence of the action of a Cu efflux system (CopYAZ) that is controlled by a Cu-sensing regulator (CopY) (15)(16)(17). The possibility that Fe ions might also be effluxed from the bacterial cell during peroxide stress has not been widely investigated.…”

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confidence: 99%

The PerR-Regulated P _1B-4 -Type ATPase (PmtA) Acts as a Ferrous Iron Efflux Pump in Streptococcus pyogenes

et al. 2017

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Streptococcus pyogenes (group A Streptococcus [GAS]) is an obligate human pathogen responsible for a broad spectrum of human disease. GAS has a requirement for metal homeostasis within the human host and, as such, tightly modulates metal uptake and efflux during infection. Metal acquisition systems are required to combat metal sequestration by the host, while metal efflux systems are essential to protect against metal overload poisoning. Here, we investigated the function of PmtA (PerRregulated metal transporter A), a P 1B-4 -type ATPase efflux pump, in invasive GAS M1T1 strain 5448. We reveal that PmtA functions as a ferrous iron [Fe(II)] efflux system. In the presence of high Fe(II) concentrations, the 5448ΔpmtA deletion mutant exhibited diminished growth and accumulated 5-fold-higher levels of intracellular Fe(II) than did the wild type and the complemented mutant. The 5448ΔpmtA deletion mutant also showed enhanced susceptibility to killing by the Fe-dependent antibiotic streptonigrin as well as increased sensitivity to hydrogen peroxide and superoxide. We suggest that the PerRmediated control of Fe(II) efflux by PmtA is important for bacterial defense against oxidative stress. PmtA represents an exemplar for an Fe(II) efflux system in a host-adapted Gram-positive bacterial pathogen.KEYWORDS iron efflux, PmtA, oxidative stress response, PerR, group A Streptococcus, Streptococcus pyogenes D efense against peroxide is recognized as one of the most widespread stress responses in prokaryotes. A characteristic of the peroxide stress response is the increased expression of peroxidases that can directly remove hydrogen peroxide as well as the induction of systems that can repair damaged proteins and nucleic acids (1, 2). Streptococcus pyogenes (group A Streptococcus [GAS]) coordinates oxidative stress responses through the action of the regulator PerR, which functions as a repressor of oxidative stress defense genes under normal conditions through binding to DNA at per boxes upstream of these genes (3, 4). This stable complex typically exists with Fe as a prosthetic group; in the presence of hydrogen peroxide, Fe causes metal-catalyzed oxidation and damage of the complex, leading to its dissociation and the subsequent transcription of peroxide response genes (3-6). In GAS, the PerR-regulated oxidative stress response encompasses both direct mechanisms, involving the detoxification of reactive oxygen species (ROS), and indirect mechanisms, which involve the repair of biomolecules damaged by oxidative stress. Direct mechanisms involving the enzymatic detoxification of reactive oxygen species are achieved through alkyl hydroperoxidases and glutathione peroxidases (1, 2, 5) as well as a single superoxide dismutase, SodA, which is Mn dependent (7). An example of an indirect response mechanism is PolAI, a DNA polymerase that repairs oxidatively damaged DNA (8).

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Role of Copper Efflux in Pneumococcal Pathogenesis and Resistance to Macrophage-Mediated Immune Clearance

Cited by 73 publications

References 51 publications

Copper Is a Host Effector Mobilized to Urine during Urinary Tract Infection To Impair Bacterial Colonization

Copper Is a Host Effector Mobilized to Urine during Urinary Tract Infection To Impair Bacterial Colonization

Copper Tolerance and Characterization of a Copper-Responsive Operon, copYAZ , in an M1T1 Clinical Strain of Streptococcus pyogenes

The PerR-Regulated P _1B-4 -Type ATPase (PmtA) Acts as a Ferrous Iron Efflux Pump in Streptococcus pyogenes

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Role of Copper Efflux in Pneumococcal Pathogenesis and Resistance to Macrophage-Mediated Immune Clearance

Cited by 73 publications

References 51 publications

Copper Is a Host Effector Mobilized to Urine during Urinary Tract Infection To Impair Bacterial Colonization

Copper Is a Host Effector Mobilized to Urine during Urinary Tract Infection To Impair Bacterial Colonization

Copper Tolerance and Characterization of a Copper-Responsive Operon, copYAZ , in an M1T1 Clinical Strain of Streptococcus pyogenes

The PerR-Regulated P 1B-4 -Type ATPase (PmtA) Acts as a Ferrous Iron Efflux Pump in Streptococcus pyogenes

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The PerR-Regulated P _1B-4 -Type ATPase (PmtA) Acts as a Ferrous Iron Efflux Pump in Streptococcus pyogenes