haemophilus spp . generally colonize the upper respiratory tract and can cause infections such as bronchitis , sinusitis , epiglottitis , pneumonia and meningitis .
h. influenzae has been reported as a rare cause of genitourinary tract infection such as urinary tract infection , , , , , pyelonephritis , , prostatitis , epididymitis , salpingitis and endometritis .
we report here an immunocompetent japanese man with bacteremic pyelonephritis caused by nontypable h. influenzae associated with a left ureteral calculus .
a 44-year - old japanese man with a history of left ureteral renal calculus presented to our hospital with a one - day history of left flank pain , fever and malaise without any respiratory symptoms .
he had left flank pain caused by a left ureteral calculus over the past two decades . otherwise , his past history and family history were unremarkable . on physical examination ,
his blood pressure was 153/91  mm hg , pulse rate 112 beats / min , respiratory rate 20 breaths / min , oxygen saturation on ambient air 98% and body temperature 38.9  c .
laboratory tests showed an elevated white blood cell ( wbc ) count 12.2    10/l and creatinine level of 1.25  mg / dl .
microscopic examination of the urine sediment showed an elevated wbc and red blood cell ( rbc ) count of 50 and 99 per high power field , respectively .
two sets of blood cultures were obtained using bactec plus aerobic / f and anaerobic / f culture bottles ( becton , dickinson and company , sparks , md ) .
urine culture was performed using sheep blood agar and drygalski improved medium ( eiken chemical co , ltd , tokyo , japan ) .
abdominal ultrasound and computerized tomography ( ct ) scan of the abdomen and pelvis without contrast showed a left ureteral calculus ( 17    10    19  mm ) , left hydronephrosis and a normal - sized prostate gland .
after admission , treatment with intravenous ceftriaxone 2  g every 24  h was initiated and the ureteral stent was inserted into his left ureter .
after 32  h of incubation , gram - negative bacilli were isolated from an aerobic blood bottle .
both blood and urine cultures using sheep blood agar and drygalski improved medium showed no growth .
chocolate ii agar ( nissui pharmaceutical co , ltd , tokyo , japan ) for blood and urine based on candle jar method at 37  c were used for culture .
the bacteria required both x factor ( hemin ) and v factor ( nicotinamide adenine dinucleotide ) for its growth .
, the united states ) automated identification and susceptibility testing showed 99.99% probability of -lactamase - negative h. influenzae biotype 3 .
it was also identified as nontypable h. influenzae by influenza bacillus immune serum kit ( denka seiken , co. , ltd , niigata , japan ) .
this organism was susceptible to ampicillin ( mic  =  0.25  g / ml ) , amoxicillin clavulanic acid ( mic    1  g / ml ) , ampicillin sulbactam ( mic    0.5  g / ml ) , ceftriaxone ( mic    0.12  g / ml ) , meropenem ( mic    0.12  g / ml ) , clarithromycin ( mic  =  4  g / ml ) , levofloxacin ( mic    0.12  g / ml ) and rifampicin ( mic    0.5  g / ml ) and resistant to sulfamethoxazole - trimethoprime ( mic  =  4  g / ml ) .
nasopharyngeal culture that was obtained after the initiation of antimicrobials was negative for haemophilus spp .
follow up blood and urine cultures were negative . on hospital day 4 , he became afebrile .
he was discharged home on hospital day 9 and treated with oral amoxicillin 1000  mg three times a day for 5 more days .
fifteen days after discharge , he underwent extracorporeal shock wave lithotrity for the left ureteral calculus .
the non - typable strains generally are not invasive and only the type b strain is preventable by vaccine .
h. influenzae has been reported as a rare cause of genitourinary tract infection and fewer case reports of genitourinary tract infections along with bacteremia due to h. influenzae .
the reported prevalence of h. influenzae in urine samples was 0.04% in women and 0.22% in men .
true prevalence of this organism in the genitourinary tract , may be underestimated , since culture media for this organism are not routinely used for urine specimens . when chocolate agar was used for routine urine cultures
showed that biotype 4 predominated in genitourinary isolates , while biotype 1 in respiratory isolates .
wallace et al . also reported that nontypable h. influenzae of biotype 4 may have been most common for genitourinary tract infection of women .
the results of these studies suggest that h. influenzae biotype 4 might have some mechanism related to the affinity to the genitourinary systems and/or direct invasion to the epithelium .
the patients were stratified by gender due to differences in clinical features . in women , 90% ( 18/20 cases ) of the patients were associated with pregnancy and , notably , 75% ( 15/20 ) had bacteremia , .
non - bacteremic urinary tract infection was only a case reported by morgan et al . .
in men , 25.6% ( 10 out of 39 cases ) of past reported patients had anatomical or functional abnormality of genitourinary tract such as renal calculus , benign prostate hypertrophy , ureteral occlusion or post - operation .
there were only 3 cases of bacteremia among the infections in males ( 7.6% ) .
therefore the true proportion of the patients with underlying diseases was possibly underestimated . regarding the serotypes of h. influenzae , a total of 66.7% ( 26 out of 39 ) was type b and 28.2% ( 11 out of 39 ) was nontypable ( 2 cases was unknown ) . in 29 out of 39 patients , biologic type of h. influenzae
thirteen were type 2 , 9 were type 3 , type 1 or 4 for 3 patients respectively and type 8 was only from one patient .
our patient had left renal calculus and serologic / biologic type was nontypable / type 3 . regardless
gender and serologic type , h. influenzae were mostly biotype 14 ( 39 out of 42 ) .
it is possible that this ability might facilitate colonization or infection in the genitourinary tract . indeed ,
urease production in the urine will produce an alkaline ph which can predispose to stone formation .
we report an immunocompetent patient with a ureteral calculus associated with bacteremic urinary tract infection caused by nontypable h. influenzae ( biotype 3 ) .
h. influenzae is difficult to grow on urine culture and its isolation may be underestimated .
collaboration between clinicians and microbiology laboratory personnel is essential for correct identification of the organism and appropriate therapy for genitourinary tract infections due to this organism .
 haemophilus species are known to colonize the upper respiratory tract and can cause infections . 
 however haemophilus influenzae has been rarely described as a cause of genitourinary tract infection . 
 we report a 44-year - old nonimmunocompromised japanese man with bacteremic pyelonephritis caused by a nontypable h. influenzae associated with a left ureteral calculus . 
 the organism was isolated from both blood and urine cultures . 
 treatment consisted of 14  days of intravenous ceftriaxone and oral amoxicillin one after than other and insertion of a left ureteral stent . after discharge 
 , he underwent extracorporeal shock wave lithotrity for the left ureteral calculus . 
 he had no recrudescence of the symptoms . 
 h. influenzae should be considered as a genitourinary pathogen among patients with certain risk factors such as anatomical or functional abnormality of genitourinary tract . 
 collaboration between clinicians and microbiology laboratory personnel is essential for correct identification of the organism and appropriate therapy for genitourinary tract infections due to this organism . 
Introduction
Case report
Discussion
Conclusion
Conflict of interests
Ethical approval