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1.  Experimental model of corynebacterium renale pyelonephritis produced in mice. 
Infection and Immunity  1977;16(1):263-267.
Corynebacterium renale type I (strain 115), 1.7 X 10(7) to 4.5 X 10(7) organisms, introduced intravenously into mice disappeared from the blood less than 24 h after inoculation and did not produce pyelonephritis. The same strain, 1 X 10(7) to 5 X 10(7) organisms, inoculated into the urinary bladder of mice was not recovered from the blood in any of the mice, but caused pyelonephritis accompanied by ureteritis and cystitis in 16 of 21 (76%) mice. Pyelonephritis and cystitis in mice were histopathologically similar to those found in cows. The antibody response was observed only in the mice with pyelonephritis or pyelitis, but not in those with only cystitis or in those without lesions, as found in cows. Similar diseases were produced in mice by C. renale types II and III but less frequently than by type I. It is suggested, therefore, that mice may be useful in the study of bovine C. renale infection.
Images
PMCID: PMC421517  PMID: 873610
2.  SWINE INFLUENZA  
1. It has been possible to demonstrate, in Berkefeld filtrates of infectious material from experimental cases of swine influenza, a virus which when administered intranasally to susceptible swine induced a mild, usually afebrile illness of short duration. The changes in the respiratory tract resembled those in swine influenza but were usually much less extensive. When the filtrable virus was mixed with pure cultures of H. influenzae suis and administered to swine a disease identical clinically and pathologically with swine influenza was induced. The data presented indicate that the filtrable virus of swine influenza and H. influenzae suis act in concert to produce swine influenza and that neither alone is capable of inducing the disease. 2. One attack of swine influenza usually renders an animal immune to reinfection. Blood serum from an animal made immune in this way neutralizes infectious material from swine influenza in vitro, as shown by the failure of the mixture to produce disease in a susceptible animal. 3. The virus can be stored in a dried state or in glycerol for several weeks at least. In one instance dried material apparently retained both the virus and H. influenzas suis in viable form for a period of 54 days. 4. Fatal cases of experimental swine influenza have been observed in which H. influenzae suis was the only organism that could be cultivated from the respiratory tract. 5. Attention has been called to some features of marked similarity between epizootic swine influenzae and epidemic influenzae in man.
PMCID: PMC2132000  PMID: 19869924
3.  Bacterial Characteristics in Relation to Clinical Source of Escherichia coli Isolates from Women with Acute Cystitis or Pyelonephritis and Uninfected Women 
Journal of Clinical Microbiology  2005;43(12):6064-6072.
Characteristics differentiating Escherichia coli strains that cause cystitis or pyelonephritis from fecal E. coli remain incompletely defined, particularly among adult women in the United States. Accordingly, phylogenetic group, O antigens, and virulence factors (VFs) were analyzed among 329 E. coli isolates from the mid-to-late 1990s from women in the United States with acute pyelonephritis (n = 170), cystitis (n = 83), or no infection (fecal; n = 76). Compared with fecal and cystitis isolates, pyelonephritis isolates exhibited a greater prevalence of phylogenetic group B2, most virulence-associated O antigens, and most VFs and had higher VF scores. In contrast, cystitis and fecal isolates differed minimally. By stepwise multivariable logistic regression, significant (P ≤ 0.015) predictors of cystitis and/or pyelonephritis (versus fecal) included afa/dra (Dr-binding adhesins), ibeA (invasion of brain endothelium), iha (putative adhesin-siderophore), malX (pathogenicity island marker), the O75 antigen, papEF (P fimbriae), papG allele II (P adhesin variant), group B2, and sfa/foc (S and F1C fimbriae). However, virulence profiles overlapped considerably among source groups and varied greatly within each group. E. coli “clonal group A” (CGA) and the O2:K5/K7:H1 and O75:K+ clonal groups were significantly associated with cystitis and/or pyelonephritis. These findings identify potential vaccine targets, suggest that urovirulence is multiply determined, and confirm the urovirulence of specific E. coli clonal groups, including recently recognized CGA.
doi:10.1128/JCM.43.12.6064-6072.2005
PMCID: PMC1317206  PMID: 16333100
4.  Comparison of Escherichia coli Strains Recovered from Human Cystitis and Pyelonephritis Infections in Transurethrally Challenged Mice 
Infection and Immunity  1998;66(7):3059-3065.
Urinary tract infection, most frequently caused by Escherichia coli, is one of the most common bacterial infections in humans. A vast amount of literature regarding the mechanisms through which E. coli induces pyelonephritis has accumulated. Although cystitis accounts for 95% of visits to physicians for symptoms of urinary tract infections, few in vivo studies have investigated possible differences between E. coli recovered from patients with clinical symptoms of cystitis and that from patients with symptoms of pyelonephritis. Epidemiological studies indicate that cystitis-associated strains appear to differ from pyelonephritis-associated strains in elaboration of some putative virulence factors. With transurethrally challenged mice we studied possible differences using three each of the most virulent pyelonephritis and cystitis E. coli strains in our collection. The results indicate that cystitis strains colonize the bladder more rapidly than do pyelonephritis strains, while the rates of kidney colonization are similar. Cystitis strains colonize the bladder in higher numbers, induce more pronounced histologic changes in the bladder, and are more rapidly eliminated from the mouse urinary tract than pyelonephritis strains. These results provide evidence that cystitis strains differ from pyelonephritis strains in this model, that this model is useful for the study of the uropathogenicity of cystitis strains, and that it would be unwise to use pyelonephritis strains to study putative virulence factors important in the development of cystitis.
PMCID: PMC108313  PMID: 9632566
5.  A CONTRIBUTION TO THE EPIDEMIOLOGY OF SPECIFIC INFECTIOUS CYSTITIS AND PYELONEPHRITIS OF COWS 
Bacteriological examination of the genito-urinary tract of calves originating in a herd in which infectious cystitis and pyelonephritis exists among the cows, revealed a variety of cultural types of diphtheroids. Of these types, one obtained from a considerable number of the calves resembled in morphology and cultural characters the organism cultivated from the actual cases of the disease. This group had agglutination affinities like those of the organism mentioned and was capable of absorbing agglutinin from antiserum specific for it. When three cows were inoculated intra-urethrally with cultures isolated from the sheaths of calves, two developed transient infections and the other a severe prolonged cystitis and pyelonephritis.
PMCID: PMC2131856  PMID: 19869737
6.  Nutritional and metabolic features of Eubacterium suis. 
Journal of Clinical Microbiology  1982;15(5):895-901.
We studied the nutritional and metabolic features of Eubacterium suis, an anaerobic animal pathogen that causes cystitis and pyelonephritis in pigs. Peptone-yeast extract-starch (PYS) medium, which contained Trypticase (BBL Microbiology Systems), yeast extract, starch, minerals, cysteine, and sodium carbonate, was shown to support excellent growth of this organism (absorbance at 600 nm = 1.8). Growth was considerably less (absorbance at 600 nm = 0.6) when the starch in the medium was replaced by maltose. Formate, acetate, and ethanol were the major products of fermentation of starch or maltose. The organism appears to require a fermentable carbohydrate for growth since the deletion of starch from PYS resulted in a negligible amount of growth. Growth decreased by approximately 20% when CO2 was rigorously excluded from PYS minus Na2CO3. The deletion of only yeast extract from PYS resulted in a decrease in growth of about 75%, and the simultaneous deletion of both yeast extract and Trypticase resulted in negligible growth. When the yeast extract in PYS was replaced by a defined mixture of purine and pyrimidine bases, vitamins, and amino acids, growth was greater than or equal to 80% that observed in PYS. The deletion of Trypticase from this medium resulted in no detectable growth, suggesting a possible peptide requirement for E. suis growth. Good growth (absorbance at 600 nm = 1.4) was obtained when adenine and uracil were substituted for the mixture of purine and pyrimidine bases in modified PYS; the substitution of pyridoxal, riboflavin, and nicotinic acid for the vitamin mixture gave comparable growth. The nutritional requirement of E. suis apparently reflect the fact that the organism adapts to its natural niche by doing away with certain biosynthetic capabilities which it does not seem to require.
PMCID: PMC272210  PMID: 6808018
7.  Streptococcus suis Causes Septic Arthritis and Bacteremia: Phenotypic Characterization and Molecular Confirmation 
Streptococcus suis is a swine pathogen that causes meningitis, septicemia, pneumonia, and endocarditis. The first case of human S. suis infection was reported in Denmark in 1968, and since then, this infection with has been reported in many countries, especially in Southeast Asia because of the high density of pigs in this region. We report the case of a patient with septic arthritis and bacteremia caused by S. suis. Cases in which S. suis is isolated from the joint fluid are very rare, and to the best of our knowledge, this is first case report of S. suis infection in Korea. The identity of this organism was confirmed by phenotypic characterization and 16S rRNA sequence analysis. An 81-yr-old Korean woman who presented with fever, arthralgia, and headache was admitted to a secondary referral center in Korea. Culture of aspirated joint fluid and blood samples showed the growth of S. suis biotype II, which was identified by the Vitek2 GPI and API 20 Strep systems (bioMérieux, USA), and this organism was susceptible to penicillin G and vancomycin. The 16S rRNA sequences of the blood culture isolates showed 99% homology with those of S. suis subsp. suis, which are reported in GenBank. The patient's fever subsided, and blood and joint cultures were negative for bacterial growth after antibiotic therapy; however, the swelling and pain in her left knee joint persisted. She plans to undergo total knee replacement.
doi:10.3343/kjlm.2011.31.2.115
PMCID: PMC3115998  PMID: 21474987
Streptococcus suis; Arthritis; Bacteremia
8.  Medical and Infectious Complications Associated with Pyelonephritis among Pregnant Women at Delivery 
Objective. Pyelonephritis is a common cause of antepartum admission and maternal morbidity. Medical complications associated with pyelonephritis during delivery are not well described; thus the objective of this study was to estimate medical, infectious, and obstetric complications associated with pyelonephritis during the delivery admission. Study Design. We conducted a retrospective cohort study using the Nationwide Inpatient Sample (NIS) for the years 2008–2010. The NIS was queried for all delivery-related discharges. During the delivery admission, the ICD-9-CM codes for pyelonephritis were used to identify cases and were compared to women without pyelonephritis. A multivariable logistic regression model was constructed for various medical, infectious, and obstetric complications among women with pyelonephritis compared to women without, while controlling for preexisting medical conditions and demographics. Results. During the years 2008–2010, there were 26,397 records with a diagnosis of pyelonephritis during the delivery admission, for a rate of 2.1 per 1000 deliveries. Women with pyelonephritis had increased associated risks for transfusion, need for mechanical ventilation, acute heart failure, pneumonia, pulmonary edema, acute respiratory distress syndrome, sepsis, acute renal failure, preterm labor, and chorioamnionitis, while controlling for preexisting medical conditions. Conclusions. Pyelonephritis at delivery admissions is associated with significant medical and infectious morbidity.
doi:10.1155/2013/124102
PMCID: PMC3804393  PMID: 24194632
9.  Differences in Virulence Factors among Clinical Isolates of Escherichia coli Causing Cystitis and Pyelonephritis in Women and Prostatitis in Men 
Journal of Clinical Microbiology  2002;40(12):4445-4449.
Differences in the presence of nine urovirulence factors among clinical isolates of Escherichia coli causing cystitis and pyelonephritis in women and prostatitis in men have been studied. Hemolysin and necrotizing factor type 1 occur significantly more frequently among isolates causing prostatitis than among those causing cystitis (P < 0.0001) or pyelonephritis (P < 0.005). Moreover, the papGIII gene occurred more frequently in E. coli isolates associated with prostatitis (27%) than in those associated with pyelonephritis (9%) (P < 0.05). Genes encoding aerobactin and PapC occurred significantly less frequently in isolates causing cystitis than in those causing prostatitis (P < 0.01 and P < 0.0001, respectively) and pyelonephritis (P < 0.01 and P < 0.0001, respectively). No differences in the presence of Sat or type 1 fimbriae were found. Finally, AAFII and Bfp fimbriae are no longer considered uropathogenic virulence factors since they were not found in any of the strains analyzed. Overall, the results showed that clinical isolates producing prostatitis need greater virulence than isolates producing pyelonephritis in women or, in particular, cystitis in women (P < 0.05). Overall, the results suggest that clinical isolates producing prostatitis are more virulent that those producing pyelonephritis or cystitis in women.
doi:10.1128/JCM.40.12.4445-4449.2002
PMCID: PMC154654  PMID: 12454134
10.  Emphysematous Cystitis: Report of an Atypical Case 
Case Reports in Urology  2011;2011:280426.
We report the atypical case of a nondiabetic 66-year old male with severe abdominal pain and vomiting who was found to have emphysematous cystitis. Of all gas-forming infections of the urinary tract emphysematous cystitis is the most common and the least severe. The major risk factors are diabetes mellitus and urinary tract obstruction. Most frequent causative pathogens are Escherichia coli and Klebsiella pneumoniae. The clinical presentation is nonspecific and ranges from asymptomatic urinary tract infection to urosepsis and septic shock. The diagnosis is made by abdominal imaging. Treatment consists of broad-spectrum antibiotics, bladder drainage, and management of the risk factors. Surgery is reserved for severe cases. Overall mortality rate of emphysematous cystitis is 7%. Immediate diagnosis and treatment is necessary because of the rapid progression to bladder necrosis, emphysematous pyelonephritis, urosepsis, and possibly fatal evolution.
doi:10.1155/2011/280426
PMCID: PMC3350004  PMID: 22606608
11.  Genotypic Analysis of E. coli Strains Isolated from Patients with Cystitis and Pyelonephritis 
Background
Urinary tract infection is the most common health problem affecting millions of people each year, mainly caused by a large genetically heterogeneous group of Escherichia coli called uropathogenic E. coli This study investigates the genotypic analysis of E. coli strains isolated from patients with cystitis and pyelonephritis.
Methods
During 2008-2009, 90 E. coli strains were analyzed, consisting of 48 isolates causing pyelonephritis in children and 42 isolates causing cystitis. Having identified the strains by standard methods, they were subtyped by pulsed field gel electrophoresis (PFGE) and their corresponding patterns were compared using dendrogram.
Results
Sixty five PFGE profiles were obtained from the genome of E. coli strains by this genotyping method. Thirty six and thirty three patterns were obtained for pyelonephritis and cystitis, respectively. Most strains exhi-bited twelve and thirteen bands and the patterns with eight or nineteen bands had the lowest rate. Genome sizes of the strains were between 1610-4170 kbp.
Conclusion
With due attention to these results, genetic patterns showed that the strains had different clonalities and it could be suggested in some cases that the strains causing pyelonephritis or cystitis have common patterns and different diseases could be explained by different gene factors.
PMCID: PMC3438433  PMID: 22997556
Uropathogenic Escherichia coli; Pyelonephritis; Cystitis; Electrophoresis; Genetic patterns
12.  Family History and Risk of Recurrent Cystitis and Pyelonephritis in Women 
The Journal of urology  2010;184(2):564-569.
Purpose
Recurrent urinary tract infections and pyelonephritis have risk factors suggesting genetic sources. Family history variables indicative of genetic risk merit further investigation. We evaluated the risk of recurrent cystitis and pyelonephritis in women with and those without a family history of urinary tract infection.
Materials and Methods
We conducted a population based case-control study of 1,261 women 18 to 49 years old enrolled in a Northwest health plan. Participants were cases identified from plan databases with documented recurrent cystitis (431) or pyelonephritis (400). Shared controls (430) were similar age women with no urinary tract infection history. We evaluated the history of urinary tract infection and pyelonephritis in first-degree female relatives (mother, sister[s], daughter[s]) and other covariates, ascertained through questionnaires and computerized databases.
Results
Of the cases 70.9% with recurrent cystitis and 75.2% with pyelonephritis, and of the controls 42.4% reported a urinary tract infection history in 1 or more female relative (p <0.001 for each case group vs controls). In both case groups odds ratios were significantly increased for women reporting a urinary tract infection history in their mother, sister(s) or daughter(s). Risk increased with a greater number of affected relatives. In women with 1 vs 2 or more relatives the ORs for recurrent cystitis were 3.1 (95% CI 2.1, 4.7) and 5.0 (3.1, 8.1), and the ORs for pyelonephritis were 3.3 (2.2, 5.0) and 5.5 (3.4, 9.0), respectively.
Conclusions
In these community dwelling women a urinary tract infection history in female relatives was strongly and consistently associated with urinary tract infection recurrence and pyelonephritis. Risk estimates increased with stronger family history indices, suggesting a genetic component for increased susceptibility to these infections.
doi:10.1016/j.juro.2010.03.139
PMCID: PMC3665335  PMID: 20639019
urinary tract infections; epidemiology; pyelonephritis; female; case-control studies
13.  Escherichia coli K5 antigen in relation to various infections and in healthy individuals. 
Journal of Clinical Microbiology  1984;19(2):264-266.
A phage specific for Escherichia coli K5 antigen was used to determine the frequency of K5 in strains of E. coli isolated from cases of sepsis, meningitis, and urinary tract infection (pyelonephritis, cystitis, and asymptomatic bacteriuria), as well as from fecal samples of healthy subjects. Although entirely absent from meningitic strains, K5 was found to be one of the most common E. coli capsular antigens, especially in strains causing sepsis. K5 was less common in the fecal strains of healthy subjects than in strains causing various urinary tract infections, between which there was no significant difference in its frequency. Thus, even if K5 is a less important antigen than K1 in the etiology of acute pyelonephritis or acute meningitis, as the fifth most commonly occurring K antigen in E. coli strains causing urinary tract infection it should be included as a component in any K antigen-based vaccine against acute pyelonephritis.
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PMCID: PMC271034  PMID: 6199369
14.  Isolation and Characterization of 89K Pathogenicity Island-Positive ST-7 Strains of Streptococcus suis Serotype 2 from Healthy Pigs, Northeast China 
The Scientific World Journal  2012;2012:302386.
Streptococcus suis is a swine pathogen which can also cause severe infection, such as meningitis, and streptococcal-like toxic shock syndrome (STSS), in humans. In China, most of the S. suis infections in humans were reported in the southern areas with warm and humid climates, but little attention had been paid to the northern areas. Data presented here showed that the virulent serotypes 1, 2, 7, and 9 of S. suis could be steadily isolated from the healthy pigs in the pig farms in all the three provinces of Northeast China. Notably, a majority of the serotype 2 isolates belonged to the 89K pathogenicity island-positive ST-7 clone that had historically caused the human STSS outbreaks in the Sichuan and Jiangsu provinces of China, although the human STSS case caused by S. suis had never been reported in northern areas of China. Data presented here indicated that the survey of S. suis should be expanded to or reinforced in the northern areas of China.
doi:10.1100/2012/302386
PMCID: PMC3373141  PMID: 22701353
15.  Xanthogranulomatous Pyelonephritis: A Retrospective Review of 16 Cases 
Korean Journal of Urology  2011;52(6):421-424.
Purpose
Xanthogranulomatous pyelonephritis is an uncommon disorder of unknown etiology that is characterized by extensive destruction of the involved kidney. It is being increasingly recognized as an important cause of renal morbidity around the world.
Materials and Methods
This retrospective study was undertaken to review the xanthogranulomatous pyelonephritis cases presented at our tertiary care referral center in Bangalore, India.
Results
A total of 16 biopsy-proven cases of xanthogranulomatous pyelonephritis from October 2007 to March 2010 treated at our institute were included in the study. There were 10 females and 6 males with a mean age of 51.5 years. Flank pain was the most common presenting symptom followed by fever. All patients had unilateral disease and underwent total nephrectomy of the affected nonfunctional kidney.
Conclusions
Xanthogranulomatous pyelonephritis is a chronic and unusual infectious inflammatory condition involving the renal parenchyma. The definite treatment is nephrectomy. Early identification and prompt treatment of this relatively benign and uncommon condition is important to minimize morbidity and mortality.
doi:10.4111/kju.2011.52.6.421
PMCID: PMC3123820  PMID: 21750755
Nephrectomy; Pyelonephritis; Xanthogranulomatous
16.  Hemorrhagic cystitis: A challenge to the urologist 
Severe hemorrhagic cystitis often arises from anticancer chemotherapy or radiotherapy for pelvic malignancies. Infectious etiologies are less common causes except in immunocompromised hosts. These cases can be challenging problems for the urologist and a source of substantial morbidity and sometimes mortality for the patients. A variety of modalities of treatment have been described for the management of hemorrhagic cystitis but there is none that is uniformly effective. Some progress has been made in the understanding and management of viral hemorrhagic cystitis. This article reviews the common causes of severe hemorrhagic cystitis and the currently available management options.
doi:10.4103/0970-1591.65380
PMCID: PMC2938536  PMID: 20877590
Hemorrhagic cystitis; immunosuppression; radiotherapy; chemotherapy; viral cystitis; intravesical therapy
17.  Characterization of porcine dendritic cell response to Streptococcus suis 
Veterinary Research  2011;42(1):72.
Streptococcus suis is a major swine pathogen and important zoonotic agent causing mainly septicemia and meningitis. However, the mechanisms involved in host innate and adaptive immune responses toward S. suis as well as the mechanisms used by S. suis to subvert these responses are unknown. Here, and for the first time, the ability of S. suis to interact with bone marrow-derived swine dendritic cells (DCs) was evaluated. In addition, the role of S. suis capsular polysaccharide in modulation of DC functions was also assessed. Well encapsulated S. suis was relatively resistant to phagocytosis, but it increased the relative expression of Toll-like receptors 2 and 6 and triggered the release of several cytokines by DCs, including IL-1β, IL-6, IL-8, IL-12p40 and TNF-α. The capsular polysaccharide was shown to interfere with DC phagocytosis; however, once internalized, S. suis was readily destroyed by DCs independently of the presence of the capsular polysaccharide. Cell wall components were mainly responsible for DC activation, since the capsular polysaccharide-negative mutant induced higher cytokine levels than the wild-type strain. The capsular polysaccharide also interfered with the expression of the co-stimulatory molecules CD80/86 and MHC-II on DCs. To conclude, our results show for the first time that S. suis interacts with swine origin DCs and suggest that these cells might play a role in the development of host innate and adaptive immunity during an infection with S. suis serotype 2.
doi:10.1186/1297-9716-42-72
PMCID: PMC3127767  PMID: 21635729
18.  Role of Uropathogenic Escherichia coli Virulence Factors in Development of Urinary Tract Infection and Kidney Damage 
Uropathogenic Escherichia coli (UPEC) is a causative agent in the vast majority of urinary tract infections (UTIs), including cystitis and pyelonephritis, and infectious complications, which may result in acute renal failure in healthy individuals as well as in renal transplant patients. UPEC expresses a multitude of virulence factors to break the inertia of the mucosal barrier. In response to the breach by UPEC into the normally sterile urinary tract, host inflammatory responses are triggered leading to cytokine production, neutrophil influx, and the exfoliation of infected bladder epithelial cells. Several signaling pathways activated during UPEC infection, including the pathways known to activate the innate immune response, interact with calcium-dependent signaling pathways. Some UPEC isolates, however, might possess strategies to delay or suppress the activation of components of the innate host response in the urinary tract. Studies published in the recent past provide new information regarding how virulence factors of uropathogenic E. coli are involved in activation of the innate host response. Despite numerous host defense mechanisms, UPEC can persist within the urinary tract and may serve as a reservoir for recurrent infections and serious complications. Presentation of the molecular details of these events is essential for development of successful strategies for prevention of human UTIs and urological complications associated with UTIs.
doi:10.1155/2012/681473
PMCID: PMC3312279  PMID: 22506110
19.  SYNERGISTIC ACTION OF HEMOPHILUS INFLUENZAE SUIS AND THE SWINE INFLUENZA VIRUS ON THE CHICK EMBRYO 
The synergistic effect of Hemophilus influenzae suis and swine influenza virus in the pig can be reproduced by the inoculation of these agents on the chorioallantoic membrane of 9 to 10 day old chick embryos. Two strains of human influenza virus that were studied failed to substitute for the swine virus in the synergistic reaction. No loss of synergistic effect was noted when the swine influenza virus was put through 11 chick embryo passages. Recently isolated and old stock strains of Hemophilus were equally able to enhance the effect of the virus. Heat-killed cultures of H. influenzae suis can be substituted for the bacterial component of the reaction. Infection of the embryo with swine influenza virus predisposes to infection with H. influenzae suis. The combination of H. influenzae suis and swine influenza virus causes a selective destruction of the embryo lungs, not produced by the individual components. This pneumonia exhibits the essential features of the natural disease.
PMCID: PMC2135289  PMID: 19871266
20.  Streptococcus suis Capsular Polysaccharide Inhibits Phagocytosis through Destabilization of Lipid Microdomains and Prevents Lactosylceramide-Dependent Recognition 
Infection and Immunity  2012;80(2):506-517.
Streptococcus suis type 2 is a major swine pathogen and a zoonotic agent, causing meningitis in both swine and humans. S. suis infects the host through the respiratory route, reaches the bloodstream, and persists until breaching into the central nervous system. The capsular polysaccharide (CPS) of S. suis type 2 is considered a key virulence factor of the bacteria. Though CPS allows S. suis to adhere to the membrane of cells of the immune system, it provides protection against phagocytosis. In fact, nonencapsulated mutants are easily internalized and killed by macrophages and dendritic cells. The objective of this work was to study the molecular mechanisms by which the CPS of S. suis prevents phagocytosis. By using latex beads covalently linked with purified CPS, it was shown that CPS itself was sufficient to inhibit entry of both latex beads and bystander fluorescent beads into macrophages. Upon contact with macrophages, encapsulated S. suis was shown to destabilize lipid microdomains at the cell surface, to block nitric oxide (NO) production during infection, and to prevent lactosylceramide accumulation at the phagocytic cup during infection. In contrast, the nonencapsulated mutant was easily internalized via lipid rafts, in a filipin-sensitive manner, leading to lactosylceramide recruitment and strong NO production. This is the first report to identify a role for CPS in lipid microdomain stability and to recognize an interaction between S. suis and lactosylceramide in phagocytes.
doi:10.1128/IAI.05734-11
PMCID: PMC3264306  PMID: 22124659
21.  Invasion of Porcine Brain Microvascular Endothelial Cells by Streptococcus suis Serotype 2  
Infection and Immunity  2004;72(3):1441-1449.
Streptococcus suis is an important swine pathogen that mainly causes meningitis and occasionally causes other infections, such as endocarditis, arthritis, and pneumonia. The pathogenesis of S. suis infection has not been completely defined. However, in order to cause meningitis, S. suis has to cross the blood-brain barrier (BBB) made up of brain microvascular endothelial cells. The objective of this work was to study the interactions of S. suis serotype 2 with porcine brain microvascular endothelial cells (PBMEC). The ability of North American and European S. suis serotype 2 strains to adhere to PBMEC and, most importantly, to invade PBMEC was demonstrated by using an antibiotic protection assay and was confirmed by electron microscopy. The polysaccharide capsule of S. suis seemed to partially interfere with the adhesion and invasion abilities of the bacterium. Our results showed that intracellular viable S. suis could be found in PBMEC up to 7 h after antibiotic treatment. Inhibition studies demonstrated that invasion of PBMEC by S. suis required actin microfilaments but not microtubular cytoskeletal elements or active bacterial RNA or protein synthesis. At high bacterial doses, suilysin-positive strains were toxic for PBMEC. The role of suilysin in cytotoxicity was confirmed by using purified suilysin, electron microscopy, and the lack of toxicity of a suilysin-negative mutant. In swine, the invasion of endothelial cells of the BBB could play an important role in the pathogenesis of the meningitis caused by S. suis.
doi:10.1128/IAI.72.3.1441-1449.2004
PMCID: PMC356020  PMID: 14977949
22.  Streptococcus suis, an Important Cause of Adult Bacterial Meningitis in Northern Vietnam 
PLoS ONE  2009;4(6):e5973.
Background
Streptococcus suis can cause severe systemic infection in adults exposed to infected pigs or after consumption of undercooked pig products. S. suis is often misdiagnosed, due to lack of awareness and improper testing. Here we report the first fifty cases diagnosed with S. suis infection in northern Viet Nam.
Methodology/Principal Findings
In 2007, diagnostics for S. suis were set up at a national hospital in Hanoi. That year there were 43 S. suis positive cerebrospinal fluid samples, of which S. suis could be cultured in 32 cases and 11 cases were only positive by PCR. Seven patients were blood culture positive for S. suis but CSF culture and PCR negative; making a total of 50 patients with laboratory confirmed S. suis infection in 2007. The number of S. suis cases peaked during the warmer months.
Conclusions/Significance
S. suis was commonly diagnosed as a cause of bacterial meningitis in adults in northern Viet Nam. In countries where there is intense and widespread exposure of humans to pigs, S. suis can be an important human pathogen.
doi:10.1371/journal.pone.0005973
PMCID: PMC2696092  PMID: 19543404
23.  Tamm-Horsfall Protein Protects Against Urinary Tract Infection by Proteus mirabilis 
The Journal of urology  2009;181(5):2332-2338.
Purpose
Proteus mirabilis is a frequent cause of urinary tract infection. We sought to determine the role of Tamm-Horsfall Protein as a host-defense factor against cystitis and pyelonephritis caused by Proteus mirabilis.
Materials and Methods
We generated Tamm-Horsfall Protein gene knockout mice by the technique of homologous recombination. We introduced Proteus mirabilis transurethrally into the bladders of the Tamm-Horsfall Protein-deficient (THP−/−) and genetically similar wild-type (THP+/+) mice. We cultured urine to quantitate the degree of bacteriuria. We examined bladders and kidneys grossly and histomorphometrically to determine the intensity of inflammation.
Results
The Tamm-Horsfall Protein-deficient mice had more severe bacteriuria, cystitis, and pyelonephritic abscesses than the wild-type mice. The difference in the severity of pyelonephritis by semiquantitative histomorphometric analysis neared but did not reach statistical significance (p=0.053).
Conclusion
Tamm-Horsfall Protein acts as a host defense factor against Proteus mirabilis induced urinary tract infection.
doi:10.1016/j.juro.2009.01.014
PMCID: PMC2930622  PMID: 19303096
knockout mice; Proteus mirabilis; cystitis; pyelonephritis
24.  Group B streptococcus cystitis presenting in a diabetic patient with a massive abdominopelvic abscess: a case report 
Introduction
Streptococcus agalactiae or group B streptococcus is a Gram-positive pathogen that is typically associated with neonatal disease and infection in pregnant women. Group B streptococcus also causes invasive infections in non-pregnant adults including urinary tract infections. The spectrum of urinary tract infections caused by group B streptococcus includes cystitis, pyelonephritis, urosepsis and asymptomatic bacteriuria, which is particularly common among elderly individuals. A rare form of invasive group B streptococcus infection in adults is secondary abscess. Here, we present the first reported case of a patient who developed an unusual, massive abdominopelvic abscess secondary to acute group B streptococcus urinary tract infection.
Case presentation
A 46-year-old African-American woman presented to the University Emergency Department complaining of urinary tract infection symptoms and severe abdominal pain. Diagnostic imaging by transvaginal ultrasound and computed tomography revealed a massive peripherally-enhancing, low-attenuating fluid collection within her pelvis. The patient’s abdominopelvic abscess was drained by ultrasound-guided drainage and this yielded a septic aspirate that was culture positive for abundant S. agalactiae. A recent history of urinary tract infection symptoms in the patient suggested that her abscess developed secondary to cystitis. Complete resolution of the abscess as a favorable outcome was achieved in this case following surgical drainage and appropriate antimicrobial therapy.
Conclusion
Acute bacterial urinary tract infection leading to an abdominopelvic abscess has not previously been reported in the literature. This case report defines a new disease etiology associated with acute streptococcal cystitis and it will be of interest in cases of urinary tract infections where there is an association with abdominal and/or pelvic pain. A brief review of the literature on unusual secondary abscesses due to group B streptococcus is provided alongside this case to highlight the clinical significance and prognoses of these rare infections. Finally, this case emphasizes the requirement to distinguish unusual etiologies of pyogenic abscesses in order to guide successful clinical management and to treat patients with antibiotics active against the causal organism.
doi:10.1186/1752-1947-6-237
PMCID: PMC3443647  PMID: 22883571
Abscess; Cystitis; Group B streptococcus; Streptococcus agalactiae; Urinary tract infection
25.  Physicochemical surface properties of Escherichia coli strains isolated from different types of urinary tract infections. 
Infection and Immunity  1981;32(2):951-955.
Escherichia coli strains isolated from three groups of patients with urinary tract infections, such as acute pyelonephritis, acute cystitis, and asymptomatic bacteriuria, were analyzed with respect to their physicochemical surface properties by means of polymer two-phase partitioning in dextran-polyethylene glycol systems and hydrophobic interaction chromatography on Octyl-Sepharose. Strains causing acute pyelonephritis constituted a homogenous group which, depending on the growth conditions, demonstrated smooth-type lipopolysaccharide, elevated negative charge, and liability to hydrophobic interaction, whereas strains isolated from acute cystitis and asymptomatic bacteriuria showed a more heterogenous pattern.
PMCID: PMC351534  PMID: 6114038

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